David Cosserat: Atmospheric Thermal Enhancement Part II – So what kind of heat flow throttling do you favour?

Posted: February 19, 2013 by David Cosserat in Analysis, climate, Energy, general circulation, methodology, Ocean dynamics
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My Thanks to David Cosserat for this second guest post, which builds on the material covered in the strongly debated part I. Although it doesn’t cover every aspect of the elevation of the surface temperature above that of an airless planet, it neatly covers the essential issues at stake between proponents on opposing sides of the ‘greenhouse effect’ debate.

Atmospheric Thermal Enhancement

Part II – So what kind of heat flow throttling do you favour?

Our goal in these articles is really quite simple. It is to determine, exactly, the mechanism that causes the Earth’s surface (land + ocean)  to have a significantly higher temperature than if it had no atmosphere at all. Is it due to the so-called radiative gases in the atmosphere such as water vapour and carbon dioxide? Or does it have some non-radiative physical cause? On this issue hangs the future of the Anthropogenic Global Warming theory.

In Part I, I discussed two possible mechanisms that might cause the temperature enhancement. One I called Throughput Throttling and the other Output Throttling. Throughput Throttling is not sensitive to radiative gas concentrations (provided those concentrations are above certain minimum levels). In contrast, Output Throttling would appear to be very sensitive to them.

Part I was intended to clear away a number of misconceptions that some skeptics have that I believe are getting in the way of a resolution of the above issue. Many skeptics tend to react against a number of ideas that appear to support the warmist cause but in reality don’t support it at all. For example they refuse to believe that:

  • Greenhouse Gases (GHGs) are an essential part of the earth-atmosphere energy transfer mechanism.
  • There is enhanced radiation from surface to atmosphere well above the net rate of inflow of energy from the Sun.
  • There is similarly enhanced ‘back radiation’ from atmosphere to surface.
  • The Trenberth energy flow model is a valuable aid to understanding the flows of energy through the earth and its atmosphere.

As long as skeptics maintain that the above propositions are false, I believe they cannot possibly engage effectively in debate with friendly warmist-inclined scientists to discuss the actual warming mechanism. This is very unfortunate because, as I hope I have demonstrated in Part I, and in the discussion trail, none of the above propositions in fact support the warmist cause anyway, even though they are believed to do so by both skeptics and warmists.

To summarise:
The presence of atmospheric GHGs are vital for converting a significant proportion of the Sun’s incoming radiation (78Wm-2) directly to Kinetic Energy in the atmosphere. This process, commonly referred to as thermalisation, heats the atmosphere. But the rate at which the thermalisation process occurs is NOT determined by the concentration of GHGs in the atmosphere (assuming there is a sufficient minimum concentration of GHGs to do the job). It is instead determined by the constant rate at which the Sun delivers energy in the bands that are directly absorbed.

  1. The earth’s surface radiates energy at an enhanced rate (356Wm-2) towards the Base of the Atmosphere. At the same time, the lowest part of the atmosphere radiates energy at an enhanced rate (333Wm-2) towards the surface. Both those figures are well above the net inflow rate from the Sun to the earth’s surface of just 161Wm-2. These enhanced flow rates more-or-less cancel one another out, the net difference being just 23Wm-2. This means that 333Wm-2 of energy circulates round and round between the two bodies (earth and atmosphere) doing no work. But this enhanced level of radiative flow is not magically produced from nowhere. It is a simple consequence of the fact that bodies at an elevated temperature radiate energy at an elevated rate (Stefan-Boltzmann law). Repeat: the enhanced radiation is a consequence of enhanced temperature levels in the surface and atmosphere and is not its cause. It does no work. Skeptics should not be afraid of that. But warmists should.
  2. The presence of atmospheric GHGs are vital for converting all of the Kinetic Energy (199Wm-2) that flows to the Top of the Atmosphere to radiation that is lost to space. This process cools the atmosphere. If you are a warmist who believes in Output Throttling, the concentration of GHGs in the atmosphere dictates the rate at which this ‘de-thermalisation’ process occurs. If you are a skeptic who believes instead in Throughput Throttling then the concentration of GHGs at the Top of the Atmosphere has no effect on the rate of flow of radiative energy because it acts simply as an open drain of energy to space (again assuming there is a sufficient minimum concentration of GHGs to do the job).

So, our investigation depends on the issue of whether or not so-called greenhouse gases (GHGs) such as water vapour and carbon dioxide are actually responsible for the atmospheric thermal enhancement (ATE) that leads to an elevated temperature above that of an airless planet. If they are, then adding additional CO2 to the atmosphere would cause a further temperature rise, with possibly alarming consequences for mankind. If they are not, then adding additional CO2 would not cause any further temperature rise, so attempts to limit man’s output of CO2 would be pointless.

The Controversial ‘Trenberth’ Figures

In summarising the conclusions of Part I, you will see I have used actual energy flux density figures rather than just relying on qualitative discussion. The figures are taken from the Earth’s Energy Balance diagram published in the 2009 paper by Trenberth, Fasullo & Kiehl.  I said then, and I repeat now, that I do not endorse these figures as being perfectly correct. Their main use is as a helpful conversational device to fix ideas on matters of scale. But I got a barrage of criticism for using them:

  • From people who thought the figures were wrong – but when challenged were unable to provide any alternative values.
  • From people who thought the figures were ludicrously accurate (3 significant figures) without having read the TFK 2009 paper where it is made clear that the numbers were just best rough estimates that came out of averaging the re-analyses of several other peoples’ work.
  • From people who appeared unable to appreciate that TFK 2009 might have done a fairly reasonable job on the energy flux density estimates, despite being regarded by skeptics as ‘wicked warmists’.
  • From people who were anxious to provide earnest advice about how to construct a much better model than Trenberth’s containing much more additional complexity – without being sensitive to the level of detail actually required for our purposes here.
  • From people who thought the model was wrong because they just hated the idea of the enhanced ‘back radiation’ loop, claiming without any proof at all that the associated upward and downward energy flow figures must  be a fabrication because they violate the 1st and/or 2nd laws of thermodynamics (they don’t).

And so on, and on…

There was one other recurring concern that I found quite baffling. Several people were uncomfortable with my insistence that the TFK 2009 model was designed to represent a steady-state energy flow scenario. How, they implied, could that be appropriate for an earth system that we know constantly undergoes change over both time and space and that is subjected to increasing levels of GHGs? Well from my viewpoint that question denied the whole objective of the model: which is to smooth out all time and spatial variations so that we are left with one that exhibits a fixed energy through-flow rate and a consequential fixed mean surface temperature. I had to explain that the model was simply a necessary starting reference point for our conversation – a balanced steady-state energy flow platform from which we could move forward in our subsequent discussion. Then we could ask questions like: what happens to the surface temperature if we do something radical like doubling the concentration of atmospheric CO2?

I confess that I remain wholly unconvinced by any of the above objections. In the final analysis, they mostly seemed to me to be ‘arm waving’ conversational ploys. As I said in Part I, for over 15 years the TFK model and figures (originally published in 1997 and updated only marginally in their subsequent 2009 paper) have remained the ‘best show in town’, despite all their undoubted imperfections.

The only significant challenge to any of the Trenberth figures that I think still needs to be addressed is an important philosophical one about the ‘back radiation’ loop: whether the uni-directional ‘upwelling’ and ‘downwelling’ radiation flows exist as separate real phenomena or are just ‘virtual’ energy flows. This issue divided commentators to the point where is spawned another blog article where we all had great fun debating whether pyrgeometer instruments, (which are specifically designed to measure uni-directional radiation, and are installed all over the world at atmospheric research centres) work accurately – or even possibly are some kind of self-referential confidence trick that don’t work at all. But whichever side you take in that ongoing debate should not detain you here (please go to that blog to register your views!) because, as you will see, in this Part II we will only be using the difference between the upwelling and downwelling figures (which is accepted by most people as a small real value).

Resistances to Energy Flow

So now let us move on to unravel the remaining part of the puzzle of why the atmosphere at the surface has a temperature that is several tens of degrees C warmer than the surface of an airless earth.

In Part I,  I described a Thought Experiment (Fig.2) to demonstrate that it is perfectly possible for a body that is well insulated from its surroundings to retain heat at a very high steady state temperature, whilst receiving a very small through-flow of energy. In the Thought Experiment, the resistance to flow, resulting in the high temperature, was provided simply by the near-perfect insulation of the container.

Now we have to consider which mechanism in the real atmosphere causes that resistance to flow that allows its temperature to be significantly elevated:

  • Is it due to a restriction on the rate at which energy can flow up the atmospheric column?
  • Is it a restriction on the rate at which energy can be converted to radiation at the Top of the Atmosphere from where it flows out of the atmosphere to space?

Of course in logic we should include other possibilities. The enhanced temperature of the atmosphere might be due to a combination of both of the above mechanisms. Or it might be due to some other entirely different cause. For the sake of clarity and simplicity, we will proceed by debating the first two ‘either/or’ possibilities, that I have dubbed Throughput Throttling and Output Throttling. We can always compromise later if we find that both effects (and/or some others) play a role.

Before considering these two contenders in more detail, we need to remember from Part I why there is an Atmospheric Thermal Enhancement effect at all (whatever mechanism proves to be correct). It has got to be due to some physical mechanism that keeps the atmosphere at a range of stable equilibrium temperatures such that the energy flowing into the earth system from the Sun exactly balances the energy flowing from the earth system out to space. This requires, as do all stable control systems, some kind of negative feedback, in this case caused by a physical resistance to energy flow.

Let us re-use our Thought Experiment apparatus from Part I, Fig. 2. But in this case we will not be considering radiation – just heat flow by conduction. This time there is no vacuum inside this new enclosure. We imagine it just contains three bodies X, Y and Z, each in contact with the next as shown in Fig. 4:

Fig. 4 - Thought Experiment 2

For this Thought Experiment we have no need of a top lid of ‘imperfect insulation’ to impede the outflow of energy. This is because the three bodies X, Y and Z are themselves imperfect insulators. That is, they possess varying conductivities, kx, ky and kz that are greater than zero but less than infinity.

Using a fixed 10 watts of through-flow power as in our previous Thought Experiment in Part I, body X (made of stainless steel) has the highest conductivity and therefore the lowest temperature difference between its lower and upper surfaces – just 0.5K. Body Y (made of glass) has a temperature difference of 10K. And body Z (made of plastic) has the largest temperature difference of 50K. This makes a total temperature drop up the column of 60.5K.

Now the important key question arises: if the total temperature difference up the column is 60.5K, what sets the corresponding absolute temperature values that are shown at the right of the column? Well, the temperature at the base is not fixed because the perfect insulation of the base prevents body X from being heated (or cooled) by a flow of energy through the base from (or to) the outside. Instead, you may remember, we postulated that the base is heated by some other means such as a 10 watt electrical heater. Therefore in this Thought Experiment, as in the previous one, the actual absolute temperatures in the column must be fixed relative to the temperature at the top – which in this case is simply the ambient temperature of the surroundings, 289K. Given this number, and the known temperature differences across the three bodies X, Y and Z, the other temperatures up the stack follow consequentially.

So what has a hypothetical insulated box containing three slices of differing solid materials got to do with an atmosphere? Well, it reminds us that:

  • At steady state, input energy flow rate = output energy flow rate (1st law of thermodynamics)
  • temperature drops are in the direction of energy flow (2nd law of thermodynamics)
  • temperature drops are different for materials that have different conductivities

and most importantly of all

  • external conditions dictate how those temperature differences relate to absolute temperature values (the 289K ambient temperature ‘anchor’ in our example).

Our Thought Experiment also has another important feature: it receives a constant input energy flow. This is not something we are very familiar with in everyday life where objects tend to heat up or cool down at reducing rates as they tend towards the ambient temperature of their surroundings. In contrast a constant flow source just…keeps on flowing at the same rate.

An analogy for constant energy flow that electrical engineers will understand is the case of a constant current source flowing through an electrical circuit that presents an overall constant resistance to the current flow and therefore develops a constant voltage difference across the circuit.

In the case of the earth-atmosphere system, the Sun provides the constant input energy flux. Energy flows through the atmosphere which provides resistance to heat flow. This develops an overall constant effective temperature difference between the ground and the top of the atmosphere where the energy is lost to space.

Simplified Earth-Atmosphere Energy Flow Model

Fig. 5 below is a slightly re-arranged and simplified version of Fig. 3 in Part 1. The energy flows are the standard ‘Trenberth’ numbers, as before:

Fig. 5 - Earth-Atmosphere Energy Flow Model

Fig. 5 shows just three energy entry routes for KE arriving into the atmosphere. The first entry route is the stream of KE derived directly from the SW radiation from the Sun (78Wm-2). The second entry route is the stream of KE derived at cloud levels from Latent Heat during precipitation (80Wm-2). The third entry route is the stream of KE derived from the surface – a combination of surface conduction/convection (17Wm-2) and surface KE-to-surface LW radiation- to-atmospheric KE (23Wm-2).

Note in particular that we now no longer show the 333Wm-2 LW radiation energy flow that was cycling around continuously between surface and atmosphere in Fig. 3. This is because this continuously cycling energy does no work and so is not part of the through-flow from Sun-to-earth-to-space – which is what we now are focusing on.

However Fig. 5 can be simplified still further by making one other (and perhaps for some people unintuitive) assumption:

It doesn’t matter at what various heights the directly absorbed solar flow of radiant energy, and the latent heat of vaporisation of surface water, are converted to Kinetic Energy.

Why doesn’t it matter? It’s all because of the Environmental Lapse Rate.

The Environmental Lapse Rate

Atmospheric pressure goes down as we ascend through the atmosphere. This is simply because the pressure at any height is determined by the fixed weight of air above that point, which obviously diminishes with increasing height above the surface.

This is summed up in the US Standard atmosphere (1987), shown in a neat graphical form in Fig. 6. The vertical axis is in kilometres above the earth’s surface. Four environmental lapse rates are shown, for pressure, density, temperature and speed of sound. Up to the tropopause, all four are negative and vary monotonically with height.

image3As we ascend through the troposphere, the reducing pressure (green line) means that each unit volume of air contains fewer and fewer molecules. In other words, it gets less dense (orange line). Lower and lower density means the air will contain less and less stored Kinetic Energy. This in turn means it also has a lower and lower temperature (red line).

The negative temperature profile up through the troposphere to the tropopause is fixed at absolute temperature values by reference to the surface. This is at the highest temperature end of the flow because the air at the bottom of the atmospheric column is in thermal contact with the surface and the surface has a temperature that relates to the rate at which it absorbs incident radiant energy from the Sun. Note that this is the opposite of our Thought Experiment above (Fig. 4) where the absolute temperatures are all referenced to the temperature of the coolest end of the column.

Ultra-simplified Earth-Atmosphere Energy Flow Model

For diagrammatic purposes in Fig. 5, the three energy streams are shown entering the atmosphere at three specific heights. Because cloud levels vary, in the cases of directly absorbed SW radiation and of Latent Heat, there will in practice be quite a wide spread of entry heights. Even in the case of the KE flowing from the surface, the 23Wm-2 fraction (radiated from the surface and then almost immediately re-absorbed in the Base of the Atmosphere) will re-appear as KE over a (short) spread of distances from the surface. So the reality is that energy flows into the atmosphere at a multiplicity of heights.

Now consider what happens when there is a flow of Kinetic Energy into the atmosphere at any particular given height. Will that layer’s temperature be raised as it absorbs that incoming energy, thus distorting the temperature lapse rate? No, because the heated air will simply convect upwards, cooling in the process, until it reaches a height at which its temperature is in equilibrium with the air surrounding it.

Therefore, for our very specific purposes here, we do not need to concern ourselves with the varying heights at which the energy enters the atmosphere, because:

At whatever height the energy flow enters, the fixed pressure profile of the atmosphere will force the energy to be redistributed so as to maintain a fixed Kinetic Energy profile in accordance with the environmental lapse rate.

So we can simply draw our diagram as if all the energy has entered at a single arbitrary point. And what better point to choose than the surface, as shown in Fig. 7 below:

image4

Wow! Simple or what? All that complicated climate sciencey stuff is now compressed down into one elementary diagram. Of course it won’t be a diagram that will be of much interest or use to people studying the intricacies of atmospheric sciences. (I fully expect it to generate many howls of anguish, just like before.) But for our purposes here it will do just fine.

We now have the simplest possible model of energy flow. It has factored out all the complications of the real earth-atmosphere system.  Look at the complexities we have lost:

  1. The insertion at a range of heights of that proportion of the Sun’s incoming radiation that is directly absorbed by the atmosphere.
  2. The conversion of KE in the surface to Latent Heat in rising water vapour.
  3. The conversion of Latent Heat to KE at a range of heights relating to cloud levels.
  4. The conversion of KE in the surface to upward radiation which is almost immediately absorbed back to KE within the Base of the Atmosphere.
  5. The conversion of KE in the Base of the Atmosphere to downward radiation which is absorbed immediately back to KE within the surface, thus (predominantly) balancing the radiative element of the upward energy flow.

We have conveniently lost all the above complexities but we haven’t forgotten them. If they turn out to be important in our subsequent discussions, we can always bring them back in.  In the meanwhile, let’s stay with the simplified diagram and see how well we get on with it.

And now for the $64 billion dollar question. What throttles the flow of energy through the atmosphere to space?  Let me describe the two competing mechanisms as succinctly as I can:

Throughput Throttling

From Fig. 7 we see that the energy lost to space through direct LW radiation (the atmospheric window) is 40Wm-2. The remainder of the energy flow, 199Wm-2, is in the form of Kinetic Energy which percolates up the atmospheric column by convection and then is lost to space at the ToA.

If convection did not exist, the atmosphere would be almost a perfect insulator. But convection does not turn the atmosphere into a perfect conductor – far from it. Convection gives the atmosphere an effective conductivity, katm, which behaves in an analogous way to the real conductivity values kx, ky and kz discussed above in Thought Experiment 2.  Strictly, to take account of the lapse rate, the layers of the atmosphere should be split into a sequence of different  effective conductivities, k1, k2, k3, ….kn, such that:

1/katm = 1/k1 + 1/k2 + 1/k3 + …….. + 1/kn

It is the combined effective conductivity katm that allows just sufficient energy through-flow to balance the Sun’s incoming energy flux whilst maintaining the fund of KE at one particular permanently elevated profile of temperatures.

If Throughput Throttling is the sole mechanism impeding energy flow though the atmosphere then adding GHGs to the atmosphere will have no effect – because the effective conductivity katm is due to a mechanical convective process that is not sensitive to the existence of GHG molecules.

Output Throttling

This proposed flow control mechanism relies on the fact that the concentration of GHGs in the atmosphere affects the average height at which GHG molecules emit photons to space. If the concentration of GHGs goes up, the average emission height goes up. Why? Because the probability of photons being intercepted by other GHG molecules at the original average height is now greater due to the increased concentration of GHGs.

However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the average energy of the photons successfully emitted to space goes down. This downgrading of energy-per-photon would cause an imbalance between energy flow into the earth-atmosphere system from the Sun and energy flow outwards to space. And  so atmospheric temperature rises to compensate until the energy balance is restored.

Under this scenario, therefore, adding additional quantities of GHGs to the atmosphere will cause the whole temperature profile of the atmosphere to rise in compensation. In particular, and, of particular importance to humans, the temperature of the air at the surface will therefore rise.

Let the debate begin

So which kind of throttling do you favour?  Are you persuaded by the skeptical argument that says that the fund of KE in the atmosphere is kept at an elevated level by the slow rate at which convection moves KE energy up the atmospheric column, which offers an ‘effective conductance’ katm that is independent of GHG concentration? And that the conversion process to radiation at the Top of the Atmosphere offers no resistance, operating like an open drain?

Or do you prefer the warmist argument that the conversion of KE to radiation at the Top of the Atmosphere is limited in proportion to the concentration of atmospheric GHGs? The higher the concentration, the cooler is the mean height at which the release of radiation to space is achieved. This forces a compensating warming sufficient to achieve the required rate of energy throughput.

There are fierce arguments to be advanced on either side but the discussions conducted here at the Talkshop will of course be mature, polite, constructive and amicable.

Here is just one very recent dialogue on another blog to get you all going:

Steven Mosher: The greenhouse effect operates by raising the ERL [effective radiation level]. A raised ERL means an earth that radiates from a higher colder region. That means a slower rate of energy release to space and the surface cools less rapidly in response.

Konrad: No, running back to the ERL thing won’t work. The ERL game was only cooked up after it became impossible to ignore that most of the energy that radiative gases radiated to space was acquired through conduction and release of latent heat, not IR from the surface. And of course we can see cloud tops radiating strongly in IR images from space. Far hotter than the surrounding air at their altitude. The altitude of radiative gases provably does not set the temperature of much of those gases at the time they are radiating the most IR. Try again.

Let (friendly) battle begin…

Comments
  1. Ronaldo says:

    Thank you for an excellent exposition of the heat transfer mechanisms, On the question of radiation from Greenhouse gases at TOA, aren’t these from relaxation of molecular vibrational modes and quantised, which would imply temperature independance. I would very much appreciate comments on this, if for no other reason than to reduce my lack of knowledge about this.

  2. Ronaldo,

    So would I 🙂

    DC

  3. Stephen Wilde says:

    “Are you persuaded by the skeptical argument that says that the fund of KE in the atmosphere is kept at an elevated level by the slow rate at which convection moves KE energy up the atmospheric column, which offers an ‘effective conductance’ katm that is independent of GHG concentration? And that the conversion process to radiation at the Top of the Atmosphere offers no resistance, operating like an open drain?”

    Yes, essentially the position that I have adopted for some time and entirely consistent with the once settled proposition that atmospheric temperatures are set only by mass and gravity subjected to an energy source.

    AGW proponents have problems with the ‘open drain’ concept. My previous analogy was a highly flexible bag with holes in it that expanded readily to any increase in pressure such that there would be little or no increase in the amount of water held by the bag when the rate of throughput increased.

    In place of the variable size of holes in a very stretchy bag we have the readily expandable atmosphere open to space.

  4. Skeptikal says:

    I don’t think either theory is right.

    But of the two proposed theories put forward, I think that the one with least likelihood of even going close to being right is the “Output Throttling” theory. Any theory which relies on increases in the levels of radiating gases in the atmosphere to elevate temperature is going to fail. The reason for this is that any rise in temperature means that more heat is available to evaporate water (water vapour is a radiating gas) and more water vapour in the atmosphere will in turn lead to an increase in temperature, hey presto… an instant runaway greenhouse, no CO2 required.

  5. Clivebest says:

    Ronaldo writes : “On the question of radiation from Greenhouse gases at TOA, aren’t these from relaxation of molecular vibrational modes and quantised, which would imply temperature independance.”

    Yes they are quantized. All photons emitted or absorbed by CO2 molecules anywhere in the atmosphere always have fixed frequencies corresponding to one of the vibrational transition lines 99% within 14-16 microns. These lines get broadened a little bit by pressure and temperature. All CO2 emitted photons are correspond to one of these line frequencies.

    The only arguments for less net CO2 radiation escaping to space at higher(cooler) altitudes are:

    1) There are fewer CO2 molecules higher up
    2) They are at a lower temperature so have less probability to be excited up to a vibrational level.

  6. pochas says:

    David Cosserat,

    You are definitely on the right track with your description of the environmental lapse rate as the controlling factor of surface temperature. Some comments:

    “2. The conversion of KE ”
    There are four modes for energy transport in the lower atmosphere. Unfortunately they all act at once through different mechanisms, thus seriously confounding the attempt to model them. They are evaporation/precipitation, clear air convection, cloud-forming convection, and radiation which is dominant at night. All are energetically favorable (2nd law) and provide the negative feedbacks that stabilize our climate. IPPC positive water vapor feedback is an elementary error.

    “4. The conversion of KE in the base of the atmosphere”
    Don’t forget “Clear Window Radiation.” This the range of spectral bandwidths that is transparent to IR. It functions as a radiative safety valve. If the other opaque bandwidths become less transparent, then there is less energy flow through the opaque bandwidths and more through the transparent “clear window” bandwidths, as is easily demonstrated by means of your electrical analogy. Nevertheless it should be remembered that the dominant mode of heat transport in the lower atmosphere in daytime is convection, and that negative feedbacks from convection will counteract increased radiance at the surface from CO2, if any.

    “However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the average energy of the photons successfully emitted to space goes down.”

    Anyone making this comment (Hi, Stephen) 🙂 is merely reciting IPCC gospel which seriously misleads. I attach a graphic which may be instructive:

    The left pane of the graphic shows a narrow band of the wavelengths shown in the right pane. Note that the left pane shows wavelengths in decreasing sequence while the right pane shows them in increasing sequence. In the left pane, the absorption band at 15 μm (220K brightness temperature) is CO2, the band at 12 μm is ozone, the bands at ~260K are water vapor, and the 280K bands are window radiation from the surface. These fall nicely in sequence of descending altitude.

    The fact is that every IR emitting component in the atmosphere has its own brightness temperature which corresponds to a definite altitude where the emission takes place and does not depend on other components present unless the bands overlap, in which case the higher altitude band obscures the lower. CO2 is a noncondensable gas so it emits at the highest coldest altitude. As seen from space it is a dark absorption line in the earth’s spectrum. The other important gas, water vapor, continues to emit at its own characteristic brightness temperature from the same lower, warmer level as always, unaffected by the CO2 emissions. It is sometimes said that pressure broadening results in a fattening of the CO2 emission line and this causes AGW. Pressure broadening takes place only at the surface and will not affect emissions from the radiating zone. The net effect of CO2 at the surface may be confined to reduced cooling rates at night at high latitudes where water vapor is diminished. So high latitudes may experience some increased minimum temperatures. I note that tropical ocean temperatures have been decreasing (UAH).

  7. Stephen Wilde says:

    “Anyone making this comment (Hi, Stephen) ”

    I don’t recall ever having made that comment. I say that IF CO2 has any effect it will expand or contract the atmosphere so that the radiating occurs at the same temperature as before but at a different height.

  8. pochas says:

    Stephen Wilde says:
    February 19, 2013 at 2:28 pm

    I’m sorry, Stephen. I was thinking of Mosher.

  9. Tim Folkerts says:

    Let me briefly make a case for “output throttling”.

    David claimed: “Therefore in this Thought Experiment, as in the previous one, the actual absolute temperatures in the column must be fixed relative to the temperature at the top – which in this case is simply the ambient temperature of the surroundings, 289K.”

    This is definitely NOT the case. The temperature at the top is determined by the “thermal contact” between the top of the insulation and the surrounding ambient temperature.

    * With still air @ 289K above the top of the insulation, the temperature of the top of the insulation will be much higher than 289 K.
    * With blowing air @ 289K above the top of the insulation, the temperature of the top of the insulation will a little cooler.
    * With finned heat-sink @ 289K above the top of the insulation, the temperature of the top of the insulation will cooler yet.
    * With circulating water @ 289K above the top of the insulation, the temperature of the top of the insulation will be even cooler.

    It is CRITICAL to know how well heat can be transferred to the surroundings, becasue this will in turn dramatically affect the temperature at the bottom. For the earth, this “transfer to the surroundings” is entirely by IR. So the IR properties dramatically affect the temperatures at the top and bottom.

    Let’s improve the Model in Figure 4 by adding a heat sink that will be at 289 K when 10 W/m^2 are flowing through the heat sink to the air in the room (the room, of course, will be a bit below 289 K to achieve this result).
    * With “ideal greenhouse gases” (black bodies for IR) at the top, then the heat sink would be at the top of the insulation, and the bottom would be at 289+60.5 K
    * With no greenhouse gases, then the heat sink would be at the bottom, and the bottom would be at 289 K.
    * “Imperfect GHGs” (Like CO2 that only absorbs in certain bands) would be like cutting the heat sink in two — and putting part at the top and part at the bottom. The temperature would be somewhere in between the two cases above.

  10. Skeptikal says, February 19, 2013 at 12:40 pm: Any theory which relies on increases in the levels of radiating gases in the atmosphere to elevate temperature is going to fail. The reason for this is that any rise in temperature means that more heat is available to evaporate water (water vapour is a radiating gas) and more water vapour in the atmosphere will in turn lead to an increase in temperature, hey presto… an instant runaway greenhouse, no CO2 required.

    Unfortunately this is not true. Otherwise the AGW debate really would have been over long ago!

    Hypothetically: If doubling CO2 produces a temperature rise of 1 degC and the consequent additional water vapour evaporation due to that rise causes a doubling of that temperature change then the total rise will be 2 degC. That’s not runaway greenhouse. Just hotter than it would be without the water vapour multiplier.

    In any case a lot of people argue that the WV multiplier is fractional due to additional clouds reflecting more of the Sun’s incident radiation back to space. Thus the increase in temperature in the above example would be much lower than 1degC, maybe close to zero.

    DC

  11. pochas says, February 19, 2013 at 1:58 pm

    You say:Nevertheless it should be remembered that the dominant mode of heat transport in the lower atmosphere in daytime is convection, and that negative feedbacks from convection will counteract increased radiance at the surface from CO2, if any.

    I am not sure I am entirely happy with the use of the term ‘negative feedbacks from convection’ in this situation. I have characterised the warming effect as being due to the slowing down of energy transport up through the atmospheric column, which has an ‘effective conductivity’ of katm. Resistance to flow IS a subtle form of negative feedback but is that exactly what you meant?

    You say: “However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the average energy of the photons successfully emitted to space goes down.” Anyone making this comment…is merely reciting IPCC gospel which seriously misleads.

    Yes, I agree. But your following rationale was a bit too complex for me to be convinced. Care to simplify it down a bit? This is the crux of the last remaining refuge of the warmist argument, so it needs spelling out very carefully for everyone here. 🙂

    DC

  12. Ronaldo says:

    Pochas, at 1.58

    Thank you for your explanation – very helpful

  13. A C Osborn says:

    Skeptikal says:
    February 19, 2013 at 12:40 pm
    more water vapour in the atmosphere will in turn lead to an increase in temperature, hey presto… an instant runaway greenhouse

    That was a Sarcasm and a JOKE right?

    Or didn’t you notice how cool the summer was in the UK with all Cloud we had this year?

  14. Tim Folkerts says:

    Pochas, let me make a slight correction to fix the misconception you were discussing.

    “However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the a̶v̶e̶r̶a̶g̶e̶ ̶e̶n̶e̶r̶g̶y̶ ̶o̶f̶ ̶t̶h̶e̶ ̶p̶h̶o̶t̶o̶n̶s̶ number of photons successfully emitted to space (from the ToA) goes down.”

    Either statement would result in less energy to space from the ToA, but the NUMBER of photons is the proper way to think of it. The photons with a wavelength of15 um will be the same energy (E = hf = hc/λ), but the cold GHGs simply emit fewer of them.

  15. Tim Folkerts says, February 19, 2013 at 2:39 pm: Let me briefly make a case for “output throttling”.

    Tim,

    But you haven’t. Instead you have tried to take a thought experiment to pieces – a good diversionary tactic.

    If it helps, I’m happy to define the surroundings of the box in Fig. 4 as a perfectly conducting heat bath that is maintained at 289K. Trying to turn that simple thought experiment into a pseudo-model of the atmospheric heat flow is not helpful. The experiment is only intended to remind us that a constant flow of power through a system sets up temperature differences but does not in itself define absolute temperatures. You need an external reference (such as a perfectly conducting heat bath) to do that.

    Turning to the realities of energy relased to space at the Top of the Atmosphere, what you need to substantiate there is the process by which you argue that increasing CO2 concentration at the ToA leads to increasing resistance to converting the KE flowing up through the atmospheric column to radiation.

    DC

  16. Tim Folkerts says:

    Pochas, one more comment. (And let me say I agree with most of what you said.)

    I want to expand on “CO2 is a noncondensable gas so it emits at the highest coldest altitude. As seen from space it is a dark absorption line in the earth’s spectrum.

    The emissions from CO2 clearly come from high in the troposphere. More specifically, the emissions to space only come from the CO2 near the ToA. The emissions from any CO2 lower down are absorbed by CO2 higher up.

    When CO2 levels increase, the key effect for global warming occurs at the ToA. The CO2 at ToA increases, so it can block a bit more IR from lower (warmer) layers, and emit more from the higher (colder) layers. This might push the “brightness temperature” down from 220 K to 215 K.

    But lowering the brightness temperature will lower the energy emitted to space in the 15 um band, which lowers the TOTAL energy emitted to space at all bands. This imbalance would persist until somethingwarmed up to emit more photons. But since all the layers of the atmosphere are tied together by the lapse rate, then all layers would warm up a bit — including the surface.

    (As has been pointed out, the lapse rate might also adjust to this change at the top (both changes in CO2 and in condensing H2O could play a role). This is a rather subtle change that would require rather sophisticated analysis to get a handle on.)

  17. Tim Folkerts says:

    David says: “If it helps, I’m happy to define the surroundings of the box in Fig. 4 as a perfectly conducting heat bath that is maintained at 289K.

    The point is that this DOESN’T help. There is NOT perfect conduction between the earth and space. The top of the atmosphere is NOT held at 2.7 K. This severely limits the ability of this model to describe the earth.

    Furthermore, you say “The experiment is only intended to remind us that a constant flow of power through a system sets up temperature differences but does not in itself define absolute temperatures.

    There is ANOTHER serious limitation of this model, which is that the “insulation” for the earth acts more like a “diode” than a “resistor”. Pretty much ANY energy flow through the atmosphere results in the SAME temperature gradient (ie the observed lapse rate). This lapse rate is about the same at the equator as at the poles (or summer and winter at the same location), while the “throughput” is vastly different. That would be like increasing the heater to 20 W in your experiment, but STILL observing a 60.5 K temperature difference!

    So yes, throughout throttling works quite well in your model. I just think that your model is SO different from the earth in these two fundamental ways that it will not tells us much about the behavior of the real earth.

  18. pochas says:

    David Socrates says:
    February 19, 2013 at 3:31 pm

    “I am not sure I am entirely happy with the use of the term ‘negative feedbacks from convection’ in this situation. I have characterised the warming effect as being due to the slowing down of energy transport up through the atmospheric column, which has an ‘effective conductivity’ of katm. Resistance to flow IS a subtle form of negative feedback but is that exactly what you meant?”

    The effective conductivity you are referring to seems to imply an exclusively radiative model which is not realistic. It does have the advantage, though, that it conveniently provides no negative feedbacks to frustrate the modelers. The author and I are urging that clouds, convection, precipitation and the thermodynamics of the atmosphere be well understood before attempting to write computer models.

    You wrote: “Yes, I agree. But your following rationale was a bit too complex for me to be convinced.”

    I’ll work on it, but a better rendition will have to wait for another day.

  19. oldbrew says:

    @ Skeptikal

    ‘it is seldom mentioned in the global warming debate that the surface cooling effect of evaporation (which creates water vapor) is stronger than its greenhouse warming effect’

    http://www.weatherquestions.com/What_is_water_vapor.htm

  20. Max™ says:

    Problem with output throttling: the Sun emits far more photons in the IR wavelengths that the surface does.

    This is often misrepresented in Sun/Earth diagrams with a downscaled Planck curve for the Sun.

    At no point is the Planck curve for emissions from the Sun at the top of the atmosphere lower than that from the surface.

    Regarding back-radiation, rather than just saying it does no work, one could say it does negative work by reducing the work which could be performed by radiation from the surface.

    As for the input/output balancing, I think the point of arguments like Postma and I prefer is that there is a geometrical property which can not be represented by any sort of constant input=output averaging method.

    You simplified the model to:

    40+199 out
    239 in

    I would simplify it to:

    _______/\_ 478 in
    40+199 out………|
    _______|_<——-
    40+199 out
    ______ \/

    Or something along those lines.

  21. mkelly says:

    Tim Folkerts says:

    February 19, 2013 at 5:48 pm
    “This might push the “brightness temperature” down from 220 K to 215 K.”

    Since the emission by CO2 of a photon at 15 micro is not thermal in nature how could it change temperature?

  22. Tim Folkerts says:

    Max says: “At no point is the Planck curve for emissions from the Sun at the top of the atmosphere lower than that from the surface.

    Not quite. At the surface of each, the curve is indeed higher for the sun than the earth at any frequency.

    However, the surface of the sun is MUCH farther away than the surface of the earth, and when you take the geometry into account, then the earth’s IR wins.

    Think of it this way — incoming sunlight above the atmosphere is ~ 1370 W/m^2, of which ~ 1% (14 W/m^2) is above 4 um. Outgoing IR is ~ 340 W/m^2, of which ~ 100 % is above 4 um.

    So earth’s IR really is above the sun’s IR throughout the thermal IR part of the spectrum.

  23. Tim Folkerts says:

    mkelly.

    The emission IS thermal in nature. Quantum mechanics determines the band where CO2 can emit, but thermodynamics determines the maximum intensity. So the temperature of the CO2 (ie the temperature of the atmosphere at that altitude) determines how intense the light is.

  24. Clivebest says:

    Tim,

    You write: “When CO2 levels increase, the key effect for global warming occurs at the ToA. The CO2 at ToA increases, so it can block a bit more IR from lower (warmer) layers, and emit more from the higher (colder) layers. This might push the “brightness temperature” down from 220 K to 215 K.”

    The deeper you delve into all this stuff, the more fascinating it all becomes! It turns out that the strongest CO2 lines exactly at 15u behave in exactly the opposite way. The reason for this is that their “effective emission height” lies way up in the stratosphere, and the temperature there actually rises with height. Increases in CO2 actually increases IR radiation loss for these central transitions.

    Our friend “scienceofdoom” has done a good job in writing a basic LBL code using HITRAN. The spectrum for the TOA difference due to a doubling of CO2 is shown here

    If you look at a satellite spectrum for example this one you will see the central peak is at a higher temperature both for CO2 and for Ozone. Both originate from the (warmer) stratosphere.

  25. Max™ says, February 19, 2013 at 7:05 pm

    You say: Problem with output throttling: the Sun emits far more photons in the IR wavelengths that the surface does.

    Yes, but so what? What does the fact that the Sun emits more photons in the IR than the surface got to do with the issue of whether the Atmospheric Thermal Enhancement is, or is not, due to Output Throttling? I see no connection. You haven’t explained the link – just made an obscure assertion.

    You say: Regarding back-radiation, rather than just saying it does no work, one could say it does negative work by reducing the work which could be performed by radiation from the surface.

    What I actually said was: “This means that 333Wm-2 of energy circulates round and round between the two bodies (earth and atmosphere) doing no work.” So that’s 333Wm-2 of back radiation AND 333Wm-2 of forward radiation. This circulation of radiative energy is simply a consequence of the temperatures of the Surface and Base of the Atmosphere and does not dissipate. Only the extra 26Wm-2 of forward radiation contributes to the flow of energy up the atmospheric column and out to space.

    You say; As for the input/output balancing, I think the point of arguments like Postma and I prefer is that there is a geometrical property which can not be represented by any sort of constant input=output averaging method. You simplified the model to…[etc]

    Max, that’s gobbledegook! If you have something important to say, and I am pretty sure you have, don’t be lazy. Please explain yourself properly. We need your input but it has got to be coherent – otherwise you will lose 90% of your audience.

    DC

  26. Tim Folkerts says, February 19, 2013 at 6:00 pm

    You say: David says: “If it helps, I’m happy to define the surroundings of the box in Fig. 4 as a perfectly conducting heat bath that is maintained at 289K.” The point is that this DOESN’T help. There is NOT perfect conduction between the earth and space. The top of the atmosphere is NOT held at 2.7 K. This severely limits the ability of this model to describe the earth.

    Once again, Tim, let me spell this out: the Fig.4 thought experiment is not intended to model the earth.

    You say: There is ANOTHER serious limitation of this model, which is that the “insulation” for the earth acts more like a “diode” than a “resistor”.

    And again, Tim, let me spell this out: the Fig.4 thought experiment is not intended to model the earth.

    DC

  27. Stephen Wilde says:

    “This means that 333Wm-2 of energy circulates round and round between the two bodies (earth and atmosphere) doing no work. But this enhanced level of radiative flow is not magically produced from nowhere. It is a simple consequence of the fact that bodies at an elevated temperature radiate energy at an elevated rate (Stefan-Boltzmann law). Repeat: the enhanced radiation is a consequence of enhanced temperature levels in the surface and atmosphere and is not its cause. It does no work. Skeptics should not be afraid of that. But warmists should.”

    Just substitute the mechanical process of decompression of rising air and compression of falling air for upward IR and downward IR with that IR exchange being relegated to a mere consequence of the mechanical process.

    No net work is done because the uplift and descent cancel out.

    That energy locked into the surface/atmosphere cycle has been there since the atmosphere first formed and is related to mass and gravity alone. It will remain locked into that cycle until the atmosphere is lost.

    That is the essence of my article about the adiabatic loop which therefore seems consistent with David’s summary.

  28. bwdave says:

    David Socrates says:
    February 19, 2013 at 10:46 pm
    “Max™ says, February 19, 2013 at 7:05 pm

    You say; As for the input/output balancing, I think the point of arguments like Postma and I prefer is that there is a geometrical property which can not be represented by any sort of constant input=output averaging method. You simplified the model to…[etc]

    Max, that’s gobbledegook! If you have something important to say, and I am pretty sure you have, don’t be lazy. Please explain yourself properly. We need your input but it has got to be coherent – otherwise you will lose 90% of your audience.”
    ———
    I think Max makes the most relevant point here, so far. Any model such as TFK that uses an “average” set of steady state conditions is a meaninless diversion that simply cannot capture, or possibly model what actually occurs in a system that that is being driven by a much greater temperature difference and in which much of the unconsidered peak solar insolation is not “thermalised” in the S/B sense at all, but rather, it is stored as latent heat.

  29. Max™ says:

    Gobbledegook?

    Distributing a hemispherical input across a sphere requires one to dilute it unrealistically and misrepresenting as being weaker than it is.

    _____

    The point about the solar IR is that any IR absorption in the upper atmosphere is likely to be direct heating from the sun, rather than reduced cooling of the surface.

    The idea that “the atmosphere is transparent to [the important] solar wavelengths, and absorbs [the important] terrestrial wavelengths” is presented as though the sun doesn’t contribute significant amounts of IR in terrestrial wavelengths, when in fact the solar IR at any part of the spectrum is greater than that from the surface, excepting portions which are absorbed completely before reaching the surface.

    This shows a misrepresentation of the curves, with the corrected surface and TOA curve for the portion of the solar curve I could find data regarding: http://i341.photobucket.com/albums/o396/maxarutaru/blackbody_zpsbef97587.png

    If anyone has info on the longer wavelengths of sunlight, let me know, it is difficult to find.

    http://rredc.nrel.gov/solar/spectra/am1.5/ASTMG173/ASTMG173.html covers down to around 4 microns.

  30. Tim Folkerts says:

    David, Let me respond more specifically to what you said at the end, rather than worry about Figure 4.

    Regarding Throughput Throttling, you say:

    “Convection gives the atmosphere an effective conductivity, katm, which behaves in an analogous way to the real conductivity values kx, ky and kz discussed above in Thought Experiment 2.

    No, it doesn’t really behave analogously to Thought Experiment 2, with an effective conductivity. Instead, convection gives the atmosphere a LAPSE RATE, with a conductivity that increases when the throughput increases, maintaining a constant temperature difference REGARDLESS of the throughput. (Yes, the throughput makes a bit of a difference in the lapse rate, but really not very much I suspect. The one exception I can think of off-hand would be with a “negative throughput” that might occur at night and create an inversion.)

    The “effective conductivity” adjusts to maintain a constant gradient, not a constant throughput (to a first order approximation).

    Regarding output throttling you say:

    However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the average energy of the photons successfully emitted to space goes down.

    As I said to Pochas earlier, this should more accurately say something like: “However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the a̶v̶e̶r̶a̶g̶e̶ ̶e̶n̶e̶r̶g̶y̶ ̶o̶f̶ ̶t̶h̶e̶ ̶p̶h̶o̶t̶o̶n̶s̶ number of photons successfully emitted to space (from the ToA) goes down.”

    * The NUMBER of photons goes down.
    * The AVERAGE ENERGY of the photons would actually go UP (the 15 um photons that get blocked are low energy — removing low energy photons pushes the average up).
    * The TOTAL ENERGY of the photons goes down.

    And so atmospheric temperature rises to compensate until the energy balance is restored.

    Yep! 🙂

  31. wayne says:

    MaxTM, I have anything about the solar radiation you might want via a Planck integrator (or any radiation as a matter of fact). Tim however is correct, at wavelengths longer than 4 μm, there is very little. However, I think you are speaking of IR being a large portion of the solar irradiance, true. Of the 1362 W/m² of solar radiance, there is 627 W/m² of near IR below red at 750 nm. And below the red that is so dark and deep and hot you would not really call it ‘red’, just when the coil on your electric stove just becomes barely visible, below 680 nm, there is 726 W/m², more than half. if you then exclude the UV and are only speaking of visible and below, it is much more than half.

    Is that what you were trying to reference?

  32. gbaikie says:

    I think the entire atmosphere of gases of earth radiates an insignificant amount of energy
    per day. Stuff other than gases, such as clouds do radiate a significant amount of energy.
    And it is the skin surfaces of earth which is radiating most of the energy.

    I believe the Earth has absorbed an enormous amount of energy- a large amount of this heat energy can found in the Earth’s oceans. Also a significant amount of this stored energy is held be the atmosphere and the stored heat of the atmosphere is the average kinetic velocity of these gases.
    If you calculated the average daily loss of air temperature globally, this same amount energy added to atmosphere per day. The same applies to the land and ocean surfaces.

    If the atmosphere and surface were to start being significant cooler than they are now, it takes
    a long time to add back this heat into the system.
    There is a few days of total solar output at Earth distance of energy in the global atmosphere and only very small portion of this total energy solar energy is being absorb per day of sunlight.

    So if you turn off the Sun, it would take days to cool down the Earth’s atmosphere, and if turn the sun back on it takes longer than days to return to the original temperature.

    With day and night cycle you turning off the Sun for about 12 hours during the night, and it’s being warmed back up during the day.
    So roughly the atmosphere holds a few days worth of heat [in the form of the kinetic motion of the gas molecules. And the entire ocean holds a few thousand years heat.

    “So now let us move on to unravel the remaining part of the puzzle of why the atmosphere at the surface has a temperature that is several tens of degrees C warmer than the surface of an airless earth.”

    I think it’s obvious that skin surface of airless earth would get much hotter during the day and the temperature of the surface during the night depends upon the amount heat which was absorbed
    during the day.
    For example the Moon has a very fluffy skin surface and despite days in the sunlight, and the surface temperature reaching 120 C, very little heat is adsorbed.
    If instead of something like over 90% of the surface covered by lunar regolith, it was instead covered with bare rocks, a lot more heat would be absorbed and it’s very long lunar nite would
    be warmer.

  33. bwdave says, February 20, 2013 at 12:29 am:

    bwdave,

    Thanks for translating Max’s third point of February 19, 2013 at 7:05 pm. See my reply to him below.

    DC

  34. Max™ says, February 19, 2013 at 7:05 pm
    Max™ says,February 20, 2013 at 2:07 am

    Max,

    As always, you have raised some important issues to discuss and here is my considered reply:

    1. IR PHOTONS
    I agree with Tim Folkert’s factual response to you on this point (February 19, 2013 at 8:28 pm) and Wayne’s (February 20, 2013 at 5:06 am ).

    But even if that were not the case, I still do not see why the ratio of incoming IR to outgoing IR matters. All the absorbed IR from the Sun, whether the 78Wm-2 portion that is absorbed directly into the atmosphere or the 161Wm-2 portion that is absorbed at the earth’s surface is thermalised to KE. Then, at some stage later (surface, clouds, ToA) that energy (along with the SW radiation from the Sun thermalised at the earth’s surface) is re-radiated as LW. You may disagree with the Trenberth numbers I have used but surely not with that principle?

    2. BACK RADIATION
    I note you have not responded to my comment on your original suggestion about back radiation being ‘negative work’. This is a crucial issue. So do you now agree with me that the 333Wm-2 radiation that circulates endlessly between earth’s surface and Base of the Atmosphere does not contribute to throughflow (“does no work”) but is simply a (perhaps just mathematical) consequence of the fact that those two bodies are facing one another, at roughly the same temperature, and are therefore bound (by S-B law) to be radiating towards one another?

    [Note: I include ‘(perhaps just mathematical)’ in deference to the feelings of those commentators to Part I who don’t believe the 333Wm-2 radiation exists. But here in Part II we are not considering what I regard as a mainly philosophical issue, and are only dealing with the 23Wm-2 net difference upwards (see my Fig. 5 above) which is the fraction of the radiation that “does work”.]

    3. INPUT/OUTPUT BALANCING
    You say, re. Postma: “Distributing a hemispherical input across a sphere requires one to dilute it unrealistically and misrepresenting as being weaker than it is.”

    I agree with that observation completely. In fact I believe that N&Z’s (revised) analysis for the ATE of ~90K, rather than than the conventional 33K, is much closer to the mark.

    But Postmas’s excellent improved model that incorporates the diurnal cycle goes way beyond what we are trying to do here where the focus is simply on discussing the mechanism that elevates the Earth’s mean surface temperature several ‘tens of degrees’ above what it would be if there were no atmosphere – but without discussing exactly how many ‘tens of degrees’ are involved. As far as I understand him (and maybe you can enlighten me to the contrary) Postma is not claiming that taking into account the earth’s rotation and a correct use of the fouth power S-B explains all of that temperature elevation. If that were all there was to it, it would also apply to the airless Moon! No there must be a physical mechanism and that is what we are trying to debate here.

    So please can we now all focus the issue of this article, the mechanism: Throughput Throttling or Output Throttling. 🙂

    DC

  35. gbaikie says:

    “But even if that were not the case, I still do not see why the ratio of incoming IR to outgoing IR matters. All the absorbed IR from the Sun, whether the 78Wm-2 portion that is absorbed directly into the atmosphere or the 161Wm-2 portion that is absorbed at the earth’s surface is thermalised to KE.”

    I can understand how dust particles, water droplets and such things can be heated directly by sunlight and because they are warmed, they in turn can warm the air.
    But I doubt it’s 78Wm-2 worth of energy.
    And don’t see how velocity of air molecules is significantly increase directly by sunlight or any radiant energy.

  36. Stephen Wilde says:

    David said:

    “the 333Wm-2 radiation that circulates endlessly between earth’s surface and Base of the Atmosphere does not contribute to throughflow ”

    I think part of it may be throughflow.

    What is happening is that at equilibrium solar input gets a free pass straight through the system such that over time energy out equals energy in.

    That invevitably involves the surface to atmosphere exchange to a considerable extent.

    However there is an additional energy exchange between surface and atmosphere which is the portion that is locked in.

    That locked in portion is the amount of energy required to create the Atmospheric Thermal Enhancement.

  37. Max™ says:

    Postma may differ, but my point is just that the day side is colder than it would be with no atmosphere, while the night side is warmer. Water in the atmosphere and oceans contribute to reducing the diurnal variation, the mass of the atmosphere determines the temperature profile through the convective zone, and the radiative properties of the atmosphere have little to no significance at all.

    I don’t use the “P=emissivity*sigma*T^4 up and down” calculation as it is an inappropriate application of the SB law.

    The temperature of the atmosphere reduces the energy lost through radiation/convection/conduction by the surface, but just as back-conduction or down-vection are nonsensical, so is treating back-radiation on it’s own.

    Saying there is 333 W/m^2 going back and forth is another way of saying “the surface and atmosphere are at least 277.15 K, if taken to be black bodies”, but no, the radiation from the atmosphere doesn’t do anything useful by itself.

    _____

    I get the idea Trenberth was going for, it is why I made my own budget, but the 78 W/m^2 counted as being absorbed in the atmosphere directly from the sun is shortwave, isn’t it?

    The atmosphere should absorb as much or more IR from the sun as it receives from the surface, which doesn’t seem to be properly accounted for, most sites with data on the solar spectrum seem to just cut off or ignore the wavelengths above 2 to 4 microns.

  38. gbaikie says, February 20, 2013 at 8:59 am

    Thank you for your response which emphasises nicely the (very large) fund of KE in the atmosphere (and the hugely much larger one in the oceans) compared with the comparatively miniscule daily throughflow of energy from the Sun to the earth system and then back out to space.

    One small clarifiation, just to make sure we are both completely on the same track:

    You say: I think the entire atmosphere of gases of earth radiates an insignificant amount of energy per day. Stuff other than gases, such as clouds do radiate a significant amount of energy. And it is the skin surfaces of earth which is radiating most of the energy.

    It is certainly true that almost all of the atmosphere (Nitrogen and Oxygen and Argon – over 99% by volume) takes no significant part at all in radiation back to space. But take a look at my Fig. 5. You may or may not agree with the precise numbers I have used there but the one thing that is certain is that almost all radiation back to space, apart from the 40Wm-2 that goes up from the surface through the so-called Atmospheric Window, comes from the atmosphere. It’s just that it comes from a tiny fraction of GHGs.

    DC

  39. gbaikie says, February 20, 2013 at 9:30 am

    You say: I can understand how dust particles, water droplets and such things can be heated directly by sunlight and because they are warmed, they in turn can warm the air. But I doubt it’s 78Wm-2 worth of energy.

    Well if you have followed Part I of this series you will know that the energy flux figures that I included in my diagrams are taken from Trenberth et.al.’s 2009 paper and that some people have hotly disputed some of them.

    My standard answer is that, until somebody shows me alternative figures, these are the ones I will use. Do you have an alternative figure to Trenberth’s 78Wm-2 figure for energy absorbed directly by the atmosphere? If so, I will be happy to assess it.

    You say: And don’t see how velocity of air molecules is significantly increase directly by sunlight or any radiant energy.

    The process is absorption. A small proportion of GHGs molecules in the atmosphere and a large proportion of liquid water molecules in clouds absorb the Sun’s incoming LW radiation thereby raising their KE by a corresponding amount.

    DC

  40. Stephen Wilde says, February 20, 2013 at 9:32 am

    Er…um…best to look at Fig. 4 in Part 1.

    356Wm-2 LW up
    333Wm-2 LW down
    23Wm-2 difference is thermalised as KE in the Base of the Atmosphere.

    The 23Wm-2 is the ‘locked in’ portion that you refer to that contributes (along with all the other thermalised flows) to maintaining the atmospheric fund of KE at its elevated level.

    So when I talk about ‘333Wm-2 circulating round and round’ between the surface and the Base of the Atmosphere, this is true arithmetically speaking – although it isn’t the same photons going round and round. 🙂

    DC

  41. Stephen Wilde says:

    Thanks David, I thought that must be what you meant.

  42. Stephen Wilde says:

    .”Water in the atmosphere and oceans contribute to reducing the diurnal variation, ”

    And every other variation.

    Which is why we must consider the oceans as part of the atmosphere for Earth but that doesn’t matter in this thread at this stage.

    I much appreciate the way that David is narrowing down this issue to just the most basic information needed to establish the real cause of the Atmospheric Thermal Enhancement.

  43. gbaikie says:

    “You say: I can understand how dust particles, water droplets and such things can be heated directly by sunlight and because they are warmed, they in turn can warm the air. But I doubt it’s 78Wm-2 worth of energy.

    Well if you have followed Part I of this series you will know that the energy flux figures that I included in my diagrams are taken from Trenberth et.al.’s 2009 paper and that some people have hotly disputed some of them.”

    Yes, and I also find many fundamental aspects which disagree about, but I would agree that some of info is based upon observational data, but the problem in the translation of the data.
    I would agree that a large portion of that sunlight is reflected- 102 of the 341 Wm-2. Though I tend think it could actually be higher number.
    I would guess the 78Wm-2 is mostly about the spectrum loss as comparing TOA to surface solar spectrum. This missing part spectrum is generally labeled “absorbed” by atmosphere, and would rather think it’s better to think of it as being blocked somehow, rather say the solar energy has been converted into heat [absorbed]. And the “blocked somehow” would be absorbed and re-emitted [emitted random direction which aren’t measured at the surface with instrument pointing at the Sun].

    Moving to the next part, being 161Wm-2 absorbed by surface. First, I would say well over 90%
    it would absorbed by the ocean and that part of the above mentioned 78Wm-2 [which “absorbed” by atmosphere] is actually reaching the surface as radiant energy- as diffused light.

    Then we get to ridiculous part. Least being the 169Wm-2 being emitted by atmosphere.
    It instead is being emitted thru the atmosphere from the surface.
    And then we get to the utter madness of 396 Wm-2 being constantly emitted from the surface. Meaning more energy should available to be harvested coming from the surface than compared to coming from sunlight.

    So if take 24 hour period, times it by 169 Wm-2, you get a daily total of 4 Kw hours of energy- so Germany gets about 2 Kw hours average solar radiance and Arizona would be 6 Kw hours or more.
    And solar panels can absorb about 20% of this energy and convert it to electrical energy, and thermal solar panel can absorb about 60% of this energy as heated water.
    The typical land surface [not including any water it may evaporate from the land] is not going to absorb more heat than manmade solar collector and an ocean will on average do better in terms of absorbing *useful heat*- useful energy for ocean is warming from 4 C to 5 C [or evaporating water] whereas that not considered useful heat for a solar collector [it’s below average air temperature- a can of water in the shade will get warmer.] .

    But the point is 396 Wm-2 over 24 hours is 9.5 Kw hours per day- a apparent energy source far superior to solar energy- if you could actually make it warm anything or somehow harvest this energy some magical manner. And in addition to the 396 Wm-2 coming from the ground, you have another 333 Wm-2 coming from the sky. If true, how could there be any worries about global energy needs?

    [Sorry but these issues have been thoroughly thrashed out in Part I, needless to say not to everyone’s satistfaction. Please stay on topic: Is it Throughput Throttling? or is it Output Throttling. DC]

  44. Kristian says:

    Does anyone know what the global mean diurnal range on Earth is? That is, what is the average difference in temperature between the nightside and the dayside hemisphere at any one time?

    I have a feeling the reason the average surface temperature of our planet is as balmy as it is, has to do with this diurnal range being exceedingly small. THAT is what the ‘atmospheric effect’ is mostly all about – evening out temperature differences. Look at the Moon. The temperature swings between night and day are huge. Therefore, as a result of the inherent exponential relation between temperature and radiative heat loss of the S-B equation, the Moon only needs to maintain a physical mean global surface temperature of less than 200K in order to be able to radiate away as much energy as it receives from the Sun.

    The Earth, on the other hand, needs to keep its mean surface temperature high above that of the Moon, because it doesn’t have those periods of very high temperatures radiating off extreme (disproportionate) amounts of energy.

    Thoughts?

  45. Tim Folkerts says, February 20, 2013 at 3:55 am

    You say: convection gives the atmosphere a LAPSE RATE, with a conductivity that increases when the throughput increases, maintaining a constant temperature difference REGARDLESS of the throughput.

    Convection gives the atmosphere a lapse rate?

    This is the reverse of the way I see things. The negative temperature lapse rate [degC/m] is not determined by convection. It is fixed by:

    (i) the weight of the atmosphere (which does not vary), resulting in a profile of pressures, Pz, reducing monotonically with height z above the surface;

    (ii) the corresponding specific heat of air at height z.

    The specific heat of air is simply the average of the specific heats of the constituent atmospheric gases, in proportion to their relative molar abundances. So CO2, being such a miniscule proportion of the dry atmospheric volume(0.04%), contributes insignificantly to this weighted average. This means that a doubling of atmospheric CO2 would not significantly change the lapse rate.

    Therefore upward convection is a consequence of the negative lapse rate not its cause, as you imply.

    Conductivity increases when the throughput increases?

    Here at last we reach the nub of the issue. Yes, the effective conductivity of the atmospheric column for the upward flow of energy by convection (perhaps better viewed for this discussion inversely as its effective resistivity) will vary locally according to the rate of vertical air flow. My effective conductivity figure katm is of course the value of conductivity relevant to the mean upflow convection rate (as it must be for any averaged energy flow model).

    So the question is, for a small change in that average energy flow, what would be the change in effective resistivity (1/katm). I would suggest that, as with all fluid flows, the incremental reduction in effective resistivity will be smaller than the corresponding incremental increase in flow rate. Thus an increasing rate of flow of rising air would meet increasing resistance, but I agree not on the scale that it would experience if katm were truly fixed.

    I do not know whether this increasing resistance has ever been calculated theoretically or measured empirically for the atmospheric column but surely it is a generally understood property of all fluids in enclosed pipes.

    I guess the problem here, on both sides of this discussion, is lack of real numbers to back either point of view. I am hoping contributors to this discussion will be able to provide them. 🙂

    re.Output Throttling

    You say:

    * The NUMBER of photons goes down.

    * The AVERAGE ENERGY of the photons would actually go UP (the 15 um photons that get blocked are low energy — removing low energy photons pushes the average up).

    * The TOTAL ENERGY of the photons goes down.

    OK, if this is the correct generally agreed description of Output Throttling, let’s go with it from now on. But, like my katm above, this also needs to be substantiated by credible numbers.

    Konrad has strong views on this. Where the heck are you, Konrad? 🙂

    DC

  46. pochas says:

    Tim Folkerts says:
    February 19, 2013 at 4:46 pm
    Pochas, let me make a slight correction to fix the misconception you were discussing.
    “However, the increase in average emission height means the emission is appearing from GHGs which are at a lower temperature – so the a̶v̶e̶r̶a̶g̶e̶ ̶e̶n̶e̶r̶g̶y̶ ̶o̶f̶ ̶t̶h̶e̶ ̶p̶h̶o̶t̶o̶n̶s̶ number of photons successfully emitted to space (from the ToA) goes down.”

    Correct. Thank You

    Tim Folkerts says:
    February 19, 2013 at 5:48 pm
    “But lowering the brightness temperature will lower the energy emitted to space in the 15 um band, which lowers the TOTAL energy emitted to space at all bands. This imbalance would persist until something warmed up to emit more photons. But since all the layers of the atmosphere are tied together by the lapse rate, then all layers would warm up a bit — including the surface.”

    Yes. At this time I can’t see how the warming effect could be completely neutralized. But it comes only from the narrow 15 micron band of CO2 which is small due to the low emitting temperature. A small amount of a small emission equals a very small effect at the surface before being further attenuated by convection and spread out between window radiation and the water bands. Lost in the noise.

  47. Kristian says, February 20, 2013 at 11:50 am

    Kristian,

    Spot on! I was amazed about a year ago when I looked at the difference in energy it took to raise the temperature of the Moon’s surface from, say 50K to 51K (Moon ‘nightime’ side) compared with the amount of energy it takes to raise the temperature from, say 300K to 301K (Moon ‘daytime’ side).

    In the first case it is ~0.026Wm-2

    In the second case it is 5.54Wm-2

    Wow! That’s 4th power in action – highly unintuitive for us humans.

    We decided not to deal with these ‘4th power’ energy asymmetries in this blog trail because our focus is narrowly on comparing two mechanisms, Throughput Throttling and Output Throttling rather than on the various other possible temperature elevating mechanisms.

    But see TB’s 6th Dec 2012 blog, Why Earth’s surface is so much warmer than the Moon’s – Part 1, for an interesting list of other possible causes of elevated temperatures.

    DC

  48. gbaikie says:

    [Sorry but these issues have been thoroughly thrashed out in Part I, needless to say not to everyone’s satisfaction. Please stay on topic: Is it Throughput Throttling? or is it Output Throttling. DC]

    “The presence of atmospheric GHGs are vital for converting all of the Kinetic Energy (199Wm-2) that flows to the Top of the Atmosphere to radiation that is lost to space. This process cools the atmosphere.”

    I don’t think GHG are doing much to cool the atmosphere. And if CO2 did much to cool an atmosphere, Venus would not be so hot.

    ” If you are a warmist who believes in Output Throttling, the concentration of GHGs in the atmosphere dictates the rate at which this ‘de-thermalisation’ process occurs. If you are a skeptic who believes instead in Throughput Throttling then the concentration of GHGs at the Top of the Atmosphere has no effect on the rate of flow of radiative energy because it acts simply as an open drain of energy to space (again assuming there is a sufficient minimum concentration of GHGs to do the job).”
    I believe the top of the atmosphere has no effect of rate radiative energy and doesn’t require
    minimum concentration of GHGs to do the job. So I suppose I am closest Throughput Throttling.

    Instead I believe that it’s possibly the largest effect of GHG might be near the surface and where one has the largest amounts of them [particularly H20]. And close might include something like a few mm above the ocean, but may also be as high as 100 meters above surface.

  49. mkelly says:

    Tim Folkerts says:

    February 19, 2013 at 5:48 pm
    “When CO2 levels increase, the key effect for global warming occurs at the ToA. The CO2 at ToA increases, so it can block a bit more IR from lower (warmer) layers, and emit more from the higher (colder) layers.”

    If CO2 from (warmer) layers are emitting the same 15 micro as the TOA colder layers than the emission is not strictly thermal in nature.

    Tim Folkerts says:

    February 19, 2013 at 8:46 pm

    mkelly.

    The emission IS thermal in nature. Quantum mechanics determines the band where CO2 can emit, but thermodynamics determines the maximum intensity. So the temperature of the CO2 (ie the temperature of the atmosphere at that altitude) determines how intense the light is.

    Since E=hv how can the intensity change?

  50. Tim Folkerts says:

    David, how about “Convection gives AN UPPER LIMIT TO the lapse rate” ?

    Or stated another way, WITHOUT convection there could be pretty much any lapse rate, depending on the throughput. WITH convection, the lapse rate is capped at ~ 6.5 K (for moist, condensing air, or ~10 K for dry, non-condensing air).

    “So the question is, for a small change in that average energy flow, what would be the change in effective resistivity?

    Well, heat flux (Φ in W/m^2) is related to the thermal conductivity (k) and the temperature gradient (ie the lapse rate, L)
    Φ = k L
    so for a typical lapse rate and typical energy flow,
    k = Φ/L = (200 W/m^2) / (0.0065 K/m) = 31,000 W/m*K

    If the lapse rate stays the same, then the changes are proportional — a 1 % increase in heat flux = 1% increase in conductivity.

  51. Tim Folkerts says:

    mkelly asks: “Since E=hv how can the intensity change?”
    That is the equation for one photon. The total energy is, of course
    E_total = n * E_photon = nhν

    More of these 15 um photons are emitted by a mole of warm CO2 than a mole of cold CO2.

  52. Kristian says:

    David says: “Convection gives the atmosphere an effective conductivity, katm, which behaves in an analogous way to the real conductivity values kx, ky and kz discussed above in Thought Experiment 2. Strictly, to take account of the lapse rate, the layers of the atmosphere should be split into a sequence of different effective conductivities, k1, k2, k3, ….kn, such that:

    1/katm = 1/k1 + 1/k2 + 1/k3 + …….. + 1/kn

    It is the combined effective conductivity katm that allows just sufficient energy through-flow to balance the Sun’s incoming energy flux whilst maintaining the fund of KE at one particular permanently elevated profile of temperatures.”

    Exactly! And the particular surface temperature needed to drive this convectional engine with the particular energy input that Earth’s global surface receives from the Sun, coupled with the specific pressure that our atmosphere exerts on it and the specific density of that same atmosphere, relating to the rate of molecular collisions -> KE on each level, so that it (the engine) can manage to maintain this balance, is … let me think … 288K.

  53. mkelly says:

    Tim Folkerts says:

    February 20, 2013 at 2:17 pm

    Thank you for the info. You were talking total.

  54. wayne says:

    Or stated another way, WITHOUT convection there could be pretty much any lapse rate, depending on the throughput. WITH convection, the lapse rate is capped at ~ 6.5 K (for moist, condensing air, or ~10 K for dry, non-condensing air).

    Tim, I have to agree there. That’s the way I see it. It takes an abnormal high rate of condensation, storms, saturated air, to drag it even closer toward isothermal. You can see that effect in action from collapsing thunder-heads not too far from sun-set. Too cool at the bottom, too warm at the top and the lapse will restore, sometimes violently.

    But on the thermal conductivity, are you sure you have that relation correct? 31,000 W/m·K? Big value! Where does that equation come from? Have a ref?

  55. tchannon says:

    TF,
    “Or stated another way, WITHOUT convection there could be pretty much any lapse rate, depending on the throughput.”

    Not so. There is a theoretic conductivity based lapse rate. This is particular. Does not exist where there is gravity.

  56. Tim Folkerts says, February 20, 2013 at 2:13 pm

    Tim,

    I don’t get this idea that convection has any effect on the lapse rate. Surely the lapse rate is only dependent on physical constants as (in the simplest example) for the Dry Adiabatic Lapse Rate where: L = g/Cp = 9.8degC/km. Introduce water and the rate goes down because of the latent heat that is released when water vapour condenses. So the Saturated Adiabatic Lapse Rate is 5degC/km. The US Standard Atmosphere lapse rate is (not surprisingly) in between these two lapse rates at 6.5degC/km. This is in effect a world mean lapse rate, so it is the one that is relevant for us to use here since we are basing our discussions on long term world mean energy fluxes.

    Therefore, in our model world, heat flowing into the atmospheric column will cause convection in conformance with the world mean lapse rate. In other words heat will rise so as to avoid disbalancing the fixed world mean lapse rate.

    How you get from there to saying that convection affects the lapse rate I do not know. It’s the other way round: the fixed lapse rate forces the convection to occur as a consequence of energy flowing in.

    DC

  57. suricat says:

    DC Says: February 20, 2013 at 11:21 am

    “[Sorry but these issues have been thoroughly thrashed out in Part I, needless to say not to everyone’s satistfaction. Please stay on topic: Is it Throughput Throttling? or is it Output Throttling. DC]”

    I don’t know how you can come to the conclusion that ‘the science is settled’ when Part 1 isn’t finished yet.

    Have you read my latest posts there? Do you continue to comment there? If not I’ll copy them here and post here.

    Best regards, Ray.

  58. Tim Folkerts says:

    David, I think you are thinking that the lapse rate is more fundamental than it is. Excuse me if oyu know much of the following, but it might help move the conversation forward for others …

    1) The equilibrium condition for a column of gas is isothermal. For example, if you create a column of gas 1m x 1m x 1000m and get it all to 300 K in a perfectly insulated container, it will all stay at 300 K. There is no ‘natural tendency’ for a lapse rate to develop. (“No temperatures differences” is pretty much the definition of “thermal equilibrium” despite what some people seem to think.)

    2) The thermal conductivity of air is about 25 mW / m*K. To set of a temperature gradient of 1K / 1000m, we would only need
    dQ/dT = k A dT/dx = (25 mW /m*K) * (1m^2) * (1K / 1000m) = 25 μW
    So if we put a 25 μW heater on the bottom and a 25 μW cooler on the top of the column, then we would create a lapse rate of 1 K/km

    3) With 10x as much power = 250 μW = 0.25 mW, we could get a lapse rate of 10 K/km. Let’s assume this is dry air in the column (and no GHGs), which puts us right at the dry adiabatic lapse rate. Any power up to 0.25 mW per square meter will simply set up conduction through the gas, and no convection.
    Put the other way around, of you wanted to hold the top at 290K and the bottom at 300 K, you would need a 0.25 mW heater on the bottom and a 0.25 mW cooler on the top.

    4) Once the power gets above 0.25 mW/m^2, then the lapse rate due simply to conduction would exceed 10 K/m. For example, if you heated the TOP and cooled the bottom by 100x 25 μW = 2.5 mW, then you would have a lapse rate of 100 K/km due to conduction. To hold the top at 300K and the bottom at 200K would require a 2.5 mW heater at the top and a 2.5 mW cooler at the bottom, and the air would conduct 2.5 mW of power.

    5) If you try to make the BOTTOM warm and the TOP cool, then you cannot exceed 10 K/km = 0.25 mW/m^2 (for dry air still). This would be unstable, with warm air at the bottom able to rise and expand while STILL remaining below the density and above the temperature of the surrounding air. Convection would commence. The convection can carry LOTS of energy by physically moving the hot atoms from the bottom to the top. To hold the top 11 K cooler than the bottom will take MUCH more power than holding the top 9K cooler than the bottom.

    SIDE NOTES:
    1) the thermal conductivity depends on both density and temperature; 25 mW / m*K is simply a typical number for air near 20 C and near 1 Atm.
    2) With GHGs in the column, then some energy can be transferred upward via IR radiation. With water in the column, then evaporation at the bottom/condensation at the top could transfer considerable energy. These would presumably increase the “effective conductivity” so that it would in practice take more than 25 μW to set up a 1 K/km lapse rate.

    RECAP:
    * The Adiabatic Lapse Rate is the gradient at which the air becomes unstable to convection. It is NOT the equilibrium condition for a column of gas.
    * The power required to initiate convection is measured in mW/m^2, while typical heating of the surface is measured in W/m^2, so in practice the such a lapse rate will (almost) always occur (both here on earth and on other planets).

    I *hope* I got that all right!

  59. suricat says:

    David Socrates says: February 20, 2013 at 11:42 pm

    “How you get from there to saying that convection affects the lapse rate I do not know. It’s the other way round: the fixed lapse rate forces the convection to occur as a consequence of energy flowing in.”

    ‘What’s ‘fixed’ and what ‘isn’t’? See below. 🙂

    ‘Au contrair’ (to the contrary), energy influx alters the ‘lapse rate’. Energy is the ‘prime mover’ and the consequences of ‘energy influx’ is ‘dissipation’ to, primarily, the nearest ‘attractor/s’. It depends on the ‘energy’ involved with ‘convection’, but ‘entropy disparity’ always falls towards the ‘nearest attractor’.

    I believe the ‘system’ is more ‘fluid’ than you suggest David. 🙂

    Best regards, Ray.

  60. gbaikie says:

    ” Tim Folkerts says:
    February 21, 2013 at 1:30 am

    David, I think you are thinking that the lapse rate is more fundamental than it is. Excuse me if oyu know much of the following, but it might help move the conversation forward for others …

    1) The equilibrium condition for a column of gas is isothermal. For example, if you create a column of gas 1m x 1m x 1000m and get it all to 300 K in a perfectly insulated container, it will all stay at 300 K. There is no ‘natural tendency’ for a lapse rate to develop. (“No temperatures differences” is pretty much the definition of “thermal equilibrium” despite what some people seem to think.)”

    So you have this container. Let’s have 2 of them, one at 14.7. And the other at 2 atm.
    And they are placed horizontal and all as you describe.
    But if they are made so they were vertical, there would some changes in terms density and pressure in the container. No doubt these changes would be more dramatic if instead 1 km it’s length was 10 km.
    With dry atmospheric air the temperature in Earth atmosphere difference with 1000 meters of elevation is 9.8 C and the air density and pressure deceases.
    Air gets more dense the colder it is- cubic meter of air at 14.7 psi which cooler is more dense
    than if warmer.
    Despite each 1000 meter of elevation with air getting colder, density is reduced per 1000 meter
    of elevation.
    So if the air wasn’t cooler 1000 meters higher- air density would be even lower as compared to the normally cooler air at such elevation.

    So with the vertical 1000 meter column one has to have lower air density at the top of column. And if you have a uniform temperature throughout the column, the air density will be even less.
    And less air per cubic meter if the air molecules are traveling the same average velocity will have a lower temperature.
    So to have uniform temperature the top of column will have have higher velocity molecules [and you will also have a higher pressure at the top of column].

  61. Max™ says:

    Wouldn’t a column of gas in a gravity well tend towards isentropic, rather than isothermal?

    You could extract work from the difference in total energy between gas at 300 K/0 km and gas at 300 K/10 km, couldn’t you?

  62. Stephen Wilde says:

    “How you get from there to saying that convection affects the lapse rate I do not know. It’s the other way round: the fixed lapse rate forces the convection to occur as a consequence of energy flowing in.”

    I think the reality is that an influx of energy tries to distort the lapse rate away from the slope fixed by gravity but in doing so causes more convection as a negative system response.

    It does take a little while for the slow convective processes to ramp up and there will be a slope distortion during that period but for so long as there is a slope distortion in one location there will be an equal and opposite slope distortion elsewhere in the overall global circulation otherwise top of atmosphere radiative balance would become permanently out of balance.

    That all assumes that the influx of energy is simply an internal redistribution of energy which is all that GHGs achieve since they do not add to energy coming in.

    An increase in energy supply from outside the atmosphere would not be a simple redistribution and therefore would have a residual effect on equilibrium temperature even after the negative system responses.

    However even then the negative system responses do greatly mitigate the effect as witness the early faint sun paradox. I think the water cycle on Earth makes the system more resistant to such changes from outside than other planets would be.

    Only more mass, more gravity or more incoming energy will raise the equilibrium temperature. Anything else (such as radiative characteristics) only affects the rates of throughput on a regional basis by altering the overall circulation.

  63. gbaikie says:

    “Only more mass, more gravity or more incoming energy will raise the equilibrium temperature. Anything else (such as radiative characteristics) only affects the rates of throughput on a regional basis by altering the overall circulation.”

    If Earth had twice or half the gravity, this would have significant effect upon raising or lowering equilibrium temperature?

    Not that I think it is a particular good idea, but if you wanted to increase the equilibrium temperature
    of Mars is there way of doing this and what would it be? [Other than changing it’s orbit].

    Would you agree that glacial and interglacial periods could said to have different equilibrium temperature?. And/or one could say the last few tens of millions of years we have been in ice box
    global climate [a different equilibrium temperature than most of last 500 million years]. Would this fit under category of a change in incoming energy? Or would this fit under changes in regional basis that happens to have particular global effect?

  64. Tim,

    Thanks for taking the trouble to provide your detailed analysis of the lapse rate issue. Don’t ever apologise for making things simple! It was well worthwhile and promted me (and possibly others) to review my own thoughts on lapse rates generally and on the form of my earlier challenges to you.

    As often is the case, this may be more a matter of language rather than substance. When I said that “convection does not have any effect of the lapse rate” I was thinking of not having any effect on the fixed lapse rate thresholds – e.g. the dry adiabatic lapse rate (9.8degC/km), saturated adiabatic lapse rate(5degC/km), and the US Standard Atmosphere lapse rate (6.5degC/km) – not the actual lapse rate that occurs at a particular place at a particular time, which is I agree very much dependent on the rate of flow of power up the atmospheric column at that particular place and time, for the reasons you clearly elaborate.

    Yes, if the power flowing up the atmosphere at some particular place and time on earth is low enough that the lapse rate it creates does not exceed the fixed lapse rate threshold (the relevant one for the atmospheric conditions there), then no convection takes place, only (miniscule) conduction. If the power flowing up that atmospheric column is such that the lapse rate it creates exceeds the relevant fixed lapse rate threshold, convection does take place and with the sudden dramatic jump in effective conductivity that you describe.

    I await you confirmation of my above analysis, because the next step is the interesting one.

    If, for example, we agree for the sake of argument that our mean energy flux model that we have (painfully) developed here in Parts I and II is subject to the US Standard Atmosphere lapse rate threshold of 6.5degC/km, then what actual average lapse rate does our model generate? If it hovers around the 6.5degC/km then the abrupt discontinuity between the low conductivity just fractionally below that threshold compared with the high effective conductivity just above, could be just the non-linear feedback mechanism that Throughput Throttling enthusiasts are looking for.

    Just a wild thought. 🙂

    DC

  65. suricat says, February 21, 2013 at 1:47 am

    Thanks for your comment. See whether my response above to Tim F helps to clear the air.

    Re. your earlier question about replies to Part I, I am still monitoring there. Apologies for my tardiness in responding.

    DC

  66. Stephen Wilde says:

    gbaike asked:

    (i) “If Earth had twice or half the gravity, this would have significant effect upon raising or lowering equilibrium temperature?”

    Yes, because a high thin atmosphere with a weak gravitational field spreads the available energy over a larger volume for a lower temperature and a shallow dense atmosphere with a strong gravitational field concentrates the available energy over a smaller volume for a higher temperature.

    (ii) “if you wanted to increase the equilibrium temperature
    of Mars is there way of doing this and what would it be?”

    Add more mass to the atmosphere or increase the gravitational field or increase incoming energy.

    (iii) “Would you agree that glacial and interglacial periods could be said to have different equilibrium temperature?. And/or one could say the last few tens of millions of years we have been in ice box
    global climate [a different equilibrium temperature than most of last 500 million years]. Would this fit under category of a change in incoming energy? Or would this fit under changes in regional basis that happens to have particular global effect?”

    Since such changes appear to be due to Milankovitch variations then they would be a result of changes in the amount of energy coming in from outside the system which does affect equilibrium temperature.

  67. Stephen Wilde says, February 21, 2013 at 9:24 am: I think the reality is that an influx of energy tries to distort the lapse rate away from the slope fixed by gravity but in doing so causes more convection as a negative system response.

    Steven,

    I agree with everything else you say except that you might (or might not!) want to slightly revise the precise wording of your statement above in the light of my recent reply to Tim F.

    DC

  68. Trick says:

    Tim F. 2/21 1:30am: “1) The equilibrium condition for a column of gas is isothermal. For example, if you create a column of gas 1m x 1m x 1000m and get it all to 300 K in a perfectly insulated container, it will all stay at 300 K. There is no ‘natural tendency’ for a lapse rate to develop. (“No temperatures differences” is pretty much the definition of “thermal equilibrium” despite what some people seem to think.)”

    David didn’t implement my Part 1 ground rule suggestion for adding a gravity vector explicitly in Fig. 5 top post so confusion on gravity continues. In my clip this post, Tim F. is correct only with no gravity.

    Once gravity vector is explicitly added to Fig. 5 in top post, a pressure gradient develops (P(z)/Po) and hence an ideal temperature gradient develops (T(p)/To from the Poisson eqn. ref. p. 78 in Wallace & Hobbs) in thermodynamic equilibrium (in time, column becomes isentropic meaning at max. entropy) for adiabatic case (dq=0).

    In words, once gravity is added to the column, the molecules can do useful work on each other until no more useful work can be done at all, this is the point of max. entropy at thermodynamic equilibrium. The Bohren text elegantly & mathematically proves the physics for those interested. With gravity turned on, T(z=max.) at top of adiabatic column becomes slightly less than To at the bottom in LTE.

  69. Stephen Wilde says:

    DC said:

    “I agree with everything else you say except that you might (or might not!) want to slightly revise the precise wording of your statement above in the light of my recent reply to Tim F.”

    Could you be specific please ?

    I see several ways that I could revise the wording but not sure if any of those revisions would deal with the point you have in mind.

  70. Tim Folkerts says:

    Let me address several issues here related to m comments about lapse rate.

    “And they are placed horizontal and all as you describe.”
    No, they are vertical. 1000 m tall.

    But if they are made so they were vertical, there would some changes in terms density and pressure in the container.
    Yes. At equilibrium, pressure decreases as you go up, density decrease as you go up, but temperature remains constant. This is one possible solution to the Ideal Gas Law.

    “So to have uniform temperature the top of column will have have higher velocity molecules”
    No. 3/2 kT = KE = 1/2 mv^2. KE is proportional to T, so molecules will the same temperature will have the same velocity whether they are at the top or the bottom of the column; whether at high density or low density. Read up on the Kinetic Theory of Gas.

    ” In my clip this post, Tim F. is correct only with no gravity.
    No, I am 99% sure that isothermal is it the answer for thermal equilibrium, even in a gravitational field. Yes, a pressure gradient is created. And a density gradient is created. But it is possible for these two gradients to balance in such a way that there is no temperature gradient.

    “and hence an ideal temperature gradient develops (T(p)/To from the Poisson eqn. ref. p. 78 in Wallace & Hobbs) in thermodynamic equilibrium (in time, column becomes isentropic meaning at max. entropy) for adiabatic case (dq=0).”
    This is the subtle step. “Adiabatic” in this case means that a parcel of air moves adiabatically from one altitude to another altitude, ie that the parcel of gas does not exchange heat with its surroundings, even if they are at a different temperature. This is only an approximation — conduction (and thermal radiation) is very poor so very little heat can flow between the parcel and the surroundings. (This is the same sort of approximation utilized in the Otto cycle where two of the processes are treated as adiabatic, when indeed they are only nearly adiabatic.) But conduction (and radiation) do exist, so the “adiabatic idealization” does not hold 100%. Put another way, because conduction is so poor, it would take a LOOOONG time for the atmosphere to come to thermal equilibrium — in the mean time, convection stirs up the atmosphere, taking it away from thermal equilibrium.

    RECAP:
    * The true thermodynamic equilibrium situation is isothermal.
    * If the system is prevented from exchanging heat from one part of the system to another part of the system, then the adiabatic lapse rate will be the expected non-equilibrium situation.
    * The earth’s atmosphere has such strong convection that the non-equilibrium, adiabatic approximation is the de facto situation.

    [Moderation note] The theoretically postulated thermodynamic equilibrium situation is isothermal. The experimentally determined thermodynamic equilibrium situation is not isothermal. ‘Truth’ is for theologians. Experimentum summas Judex – Experiment is the final arbiter – Albert Einstein.

  71. Stephen Wilde says:

    “a pressure gradient is created. And a density gradient is created. But it is possible for these two gradients to balance in such a way that there is no temperature gradient.”

    What about the progressive conversion of KE to PE as one goes higher to levels of lower pressure and density ?

    PE does not register as temperature so there must be a reduction in temperature with height even though the energy content of each molecule stays the same from top to bottom.

  72. Stephen Wilde says:

    ” convection stirs up the atmosphere, taking it away from thermal equilibrium. ”

    In fact, any deviation from equilibrium stirs up the atmosphere and the resulting convection takes it back towards equilibrium.

  73. Max™ says:

    Thought experiment: what would be the result if you added enough N2 and O2 to double the mass of the Martian atmosphere?

  74. gbaikie says:

    “Thought experiment: what would be the result if you added enough N2 and O2 to double the mass of the Martian atmosphere?”

    Mars has very thin atmosphere, if you double the atmosphere, you still need a pressure suit
    to breathe [can’t just use face mask, need spacesuit].

    With such a doubled atmosphere, it should not effect very much the amount of sunlight reaching the surface- most noticeable reduction in amount sunlight reach the surface should be when the sun is at low angle, but not significant.

    The biggest effects should be a reduction in polar ice caps- less CO2 ice should form in winter.
    Also seems one would get more H20 gas in atmosphere. And dust storm should be more intense and longer lasting.
    One should on practical level make Mars colder, more heat loss from structures and people- so “feels colder” but should be slighter warmer in in terms of warmer nights and warmer surface air during daylight. Or presently during day time skin surface may reach 80 F, but surface air drops in temperature significantly just one meter above the surface. So doubling the atmosphere should
    have less drop in temperature in first 10 meter above the surface.

  75. gbaikie says:

    One more thing, Mars: “Total mass of atmosphere: ~2.5 x 10^16 kg”
    So, 2.5 x 10^13 tonnes- 25 trillion tonnes.
    If added 25 trillion tonnes of water [or brought trillions tonnes of water from
    beneath the mars surface] as liquid water at surface it would much larger
    effect upon global temperatures.

    [Guys, this is way off topic, please desist. “Throughput Throttling” versus “output Throttling” is the matter of debate here. Remember? 🙂 DC]

  76. Tim Folkerts says:

    Stephen ponders: “What about the progressive conversion of KE to PE as one goes higher to levels of lower pressure and density ?

    This is subtle. There is a self-selection process going on. As you go up, the slowest molecules from the layer below don;t make it up to the next layer (hence the decrease in density). Only the high-energy molecules with above-average KE make it up. But they lose some KE on the way (that “progressive conversion you mention). The net result is that the average KE stays the same as you go up!

  77. Stephen Wilde says, February 21, 2013 at 2:50 pm: DC said: “I agree with everything else you say except that you might (or might not!) want to slightly revise the precise wording of your statement above in the light of my recent reply to Tim F.” Could you be specific please ?

    Stephen,

    Yes, sorry, I could have done better but I didn’t have much time this morning. Here goes with the long version. I shall also be interested to see whether Tim F agrees with this.

    You had said, Feb 21, 2013 at 9:24 am: I think the reality is that an influx of energy tries to distort the lapse rate away from the slope fixed by gravity…

    No. The point Tim F was making (if I have understood him correctly) is that the actual measurable temperature lapse rate is NOT fixed only by gravity. It is also a function of energy throughflow. To see why this is so, I offer the following rationale.

    First of all, I think we all agree that what IS fixed by gravity is the pressure lapse rate which is determined solely by the weight of the atmosphere and remains fixed irrepective of temperature (as long as the temperature is high enough for the atmosphere to remain gaseous!!)

    Now given the atmosphere’s fixed pressure lapse rate, and given also the fixed aggregate specific heat, Cp, of its constituent gases, it is easy to show that the corresponding actual measurable temperature lapse rate MUST be influenced by the rate at which energy flows through it…

    For example (and ignoring the small practical issue about liquifaction or solidification at low pressures!!), if NO energy flows at all, there would obviously be no lapse rate. And at the opposite extreme, if the Sun’s energy flow rate were to be twice its current value, consequently elevating surface temperature very considerably, we would be hardly surprised to find that the lapse rate went up. How could it not?

    In reality, we know (from measurements) that on average 199Wm-2 flows up the atmospheric column. And we also know (from measurements) that the corresponding mean real lapse rate is about 6.5degC/km, as defined for the US Standard Atmosphere. Of course, real lapse rates at different points all over the world, and at different points in time, will be spread above or below this figure. All these individual real lapse rate variations are just part and parcel of the chaotic behaviour of the real atmosphere.

    So much for constantly fluctuating real lapse rates

    We now come to the things that are unfortunately called lapse rates but, I believe, could much more helpfully be called lapse rate thresholds.

    (1) If the real lapse rate of a column of completely dry air is greater than the dry adiabatic lapse rate threshold of 9.8degC/km, it will convect.

    (2) If the real lapse rate of a column of air saturated with water vapour is greater than the saturated adiabatic lapse rate threshold of 5degC/km, it will convect.

    Thus at a particular place and at a particular time on the earth, if the atmosphere is dry and the rate at which energy is rising up is sufficiently high to generate a real measurable lapse rate in excess of 9.8degC/km, then the air will convect.

    And if, a particular place and time on earth, the atmosphere is saturated with water vapour and the rate at which energy is rising up is sufficiently high to generate a real measurable lapse rate in excess of 5degC/km, then the air will convect.

    In short, the lapse rate thresholds are fixed. But the countless real measurable lapse rates, all over the earth, are different from place to place, and time to time.

    If you agree with the above rationale, your statement of Feb 21, 2013 at 9:24 am I think the reality is that an influx of energy tries to distort the lapse rate away from the slope fixed by gravity… is not quite compatible with it.

    DC

  78. Tim Folkerts says:

    Max asks “Thought experiment: what would be the result if you added enough N2 and O2 to double the mass of the Martian atmosphere?”

    It would significantly warm the surface — for a couple different reasons that I can think of off-hand.

    1) The increased “thermal mass” will help even out the temperatures from day to night — making the day side cooler and the night side warmer. Any smoothing out of the temperatures helps raise the average temperature.

    2) The increased # of moles will make the atmosphere thicker and will raise the “top of atmosphere”. The top will be cooler (due to the lapse rate effect). Since the top becomes cooler, the radiation from the “top of atmosphere” will decrease, and the radiation from the surface (and hence the temperature) must increase to re-establish energy balance.

  79. Trick says:

    Tim F. 3:43pm: “No, I am 99% sure that isothermal… dq=0 This is the subtle step…”

    Mod. note: “The theoretically postulated thermodynamic equilibrium situation is isothermal.”

    Geez, you guys. It is 100% sure that ideal but subtle dq=0 soln. theory IS isentropic LTE T(p) since that is the physics (since Poisson eqn.). Just need to nudge Tim F. 1% to get out the modern theory & look for that last 1% evidence. The modern theoretically postulated thermodynamic equilibrium column IS isentropic at max. entropy point by 2nd law. Really neat atm. physics shows this. Readers here should be interested in it (e.g. see Bohren 1998 text detail).

    If there is any free energy to do useful work in molecule collisions in Tim’s unforced adiabatic column, nature uses the free energy to make more entropy up to max. This process results in the heat death of Tim’s 1km subtle dq=0 adiabatic column same as the adiabatic universe when there will not be enough free energy existing to do any useful work.

    Tim F. – Yes, the model IS idealized dq=0 adiabatic both for boundary and parcel which is close enough to real life so a lot can be learned from the ideal condition. That’s what the dq=0 means at boundary and at parcel level (and is ok w/2nd law reversible processes); you can see it exactly enforced in the math proving isentropic T(p) varying with pressure at LTE for m^2 column Fig. 5 if ideally unforced & no heat and work exchange w/surroundings. This is the early beginning of the lapse rate actually.

    When forced as in Fig. 5, the column entropy is always below the max. attainable as is the To and the lapse rate becomes the observed lapse up from Fig. 5 To=287K. Yes, Tim, a change in pressure happens at the speed of sound, temperature changes much more slowly: wait LOOOOng time for LTE.

    The potential temperature To is a conserved quantity in the adiabatic idealization, remaining constant like density in an incompressible fluid. Of course in reality dq is never = 0 but setting dq=0 is close enough to get paid for some government work.

    Interesting to think of the top of an otherwise adiabatic column being open to deep space as in Fig. 5 so only radiation gets out. What then happens is discussion worthy. Pretty sure Stephen will say top goes up and down so include thinking Kelvin-Helmholtz theory say like for Uranus. And a Uranus gravity vector downward.

    ******

    As far as the KE throttling (no math defn.of “throttle” given), both radiation and conduction are “percolating” KE (no math defn. “percolate” either). Really all three: conduction, radiation AND convection exist and operate (“percolate KE”) in the m^2 column Fig. 5. And all those have math defn.s. (approx. Fourier, exact Planck and quantum, approx. parcel meteorology) for which the basic heat eqn. theory computes Teq. from measured earth input data remarkably close to observed earth Tavg. Neither throughput nor output “throttle” choice works all alone so neither can derive observed earth Tavg. as well as the complete theory.

    Is that lucid David? Ask for clarification if not as lotsa’ interesting math & ref. exposition skipped over for such “brevity”. Such as it is w/o a decent editor on my staff.

    [DC: Trick I long since gave up on trying to follow your convoluted explanations. Sorry!]

  80. Stephen Wilde says:

    David,

    Thanks for the clarification and I’ve given it some thought.

    My initial feeling is that the concept of lapse rate thresholds other than the one set by gravity are likely an unnecessary complication.

    The only lapse rate that must be met for an atmosphere to be retained is the one set by gravity. All other lapse rates must dance around that single ‘threshold’.

    All other lapse rates including the one set by water vapour are just a variant of the real lapse rates which are all dependent on the composition of the atmosphere at any given location. In the troposphere the effect of water vapour swamps all else and in the stratosphere the effect of ozone swamps all else.

    Even the dry rate is just a variant of the real lapse rates because the composition of the molecules even in dry air are not a pure representation of the lapse rate set by gravity.

    In reality no atmosphere exactly matches the theoretical lapse rate set by gravity and so every atmosphere has to have a circulation in order to get the distorting effect of the atmosphere removed so that radiative balance can be achieved at top of atmosphere.

    It doesn’t matter whether the compositional variants result in mechanical or radiative consequences. Either way the atmospheric circulation must reconfigure so that the infinite variations of real lapse rates always net out to the pure theoretical lapse rate set by gravity.

    That pure theoretical lapse rate is itself defined by the netted out value of all the real world lapse rates otherwise there would be no top of atmosphere balance and no atmosphere.

    One can then see that my statement is compatible with all the real world lapse rates being indicative of the rate of throughput, some being faster (water vapour in troposphere) and some slower (ozone in the stratosphere) than the ideal gravity set lapse rate.

    The important thing is that all those faster and slower rates of throughput must net out to zero between surface and top of atmosphere so that the pure gravity set lapse rate is observed overall.

    Any lapse rate faster than the ideal one accelerates energy throughput and any lapse rate slower than the ideal one decelerates energy throughput and any net divergence from the ideal lapse rate is simply resolved by a change in circulation and atmospheric volume just sufficient to negate the discrepancy.

    In reality we see variations around the mean all the time due to the time it takes for negative system responses to adapt to forcing elements.

    If the atmosphere gets too warm so that more is going out than coming in then the excess going out causes cooling (atmospheric contraction) back to the initial equilibrium temperature.

    If the atmosphere gets too cool so that more is coming in than going out then the surplus coming in causes warming (atmospheric expansion) back to the initial equilibrium temperature.

    That initial equilibrium temperature being set only by mass held by gravity and subjected to a flow of energy from outside the atmosphere.

    Changes in composition whether of radiative or of other properties of molecules cannot change equilibrium temperature. They can only affect the circulation pattern within an expanded or contracted atmosphere.

  81. Tim Folkerts says:

    The Moderator correctly notes: ” The theoretically postulated thermodynamic equilibrium situation is isothermal.
    I agree 100%.

    The moderator then makes the odd addition: “The experimentally determined thermodynamic equilibrium situation is not isothermal.”
    No, the experimentally determined NON-equilibrium situation is not isothermal. The experimentally determined quasi-adiabatic situation agrees with the theoretical adiabatic situation (ie a stable lapse rate).

    PS. You might want to inform Hans Jelbring that the theoretical equilibrium situation is isothermal. He (and many others) seem quite convinced that the adiabatic lapse rate is the true thermodynamic equilibrium solution.

    “It has been shown by Jelbring 2003 (ref 2) that the an energetically closed planetary atmosphere under the impact of gravity which is allowed to come to rest for a long time (no winds and no temperature inversions) has to develop a “static” dry adiabatic temperature lapse rate that is equal to the “dynamic” one mentioned above.
    https://tallbloke.wordpress.com/2012/01/25/hans-jelbring-an-alternative-derivation-of-the-static-dry-adiabatic-temperature-lapse-rate/

    and

    “A simplified model of Earth will be considered. The model planet does not rotate. It
    neither receives solar radiation nor emits infrared radiation into space. …
    Equilibrium atmospheric conditions have been reached …
    The temperature lapse rate in our model atmosphere also has to be –g/cp.
    https://tallbloke.wordpress.com/2012/01/01/hans-jelbring-the-greenhouse-effect-as-a-function-of-atmospheric-mass/

  82. Trick says:

    Tim F. “I agree 100%”

    LOL, where did the 1% come from now? Adiabatic column can only be at thermal equilibrium isothermal transiently, once thermodynamic equilibrium max. entropy is achieved in time, there is no free energy & get heat death with the math solution proving T gradient is Poisson eqn. What part of Poisson eqn. derivation do you disagree with?

  83. Kristian says:

    Tim,

    I think what the moderator is trying to tell you is that, of course the equilibrium situation would be isothermal. A system in thermodynamic equilibrium is per definition isothermal, simply as a function of there being no net flows of energy. It is simply an excercise in redundancy making a point out of this fact, as if it were a new or controversial discovery of some kind.

    What is relevant is whether a system like our (Sun-)surface-atmosphere will ever reach such a state of equilibrium. Theoretical concept versus real world situation.

  84. Tim Folkerts says:

    Kristian, I agree with you. But what you & I consider obvious has been considered wrong by many, most notably Jelbring who wrote a paper “proving that an adiabatically sealed container will achieve a lapse rate at equilibrium. You and I and many others may say “of course”, but a couple of threads here and a thread at WUWT (with over 1000 comments!) shows that there is considerable disagreement with this simple conclusion!

  85. Tim Folkerts says:

    Trick, I am having a little trouble deciphering exactly what you are saying February 21, 2013 at 11:36 pm.

    ” Adiabatic column can only be at thermal equilibrium isothermal transiently …”
    Do you mean ‘An adiabatic column which is at thermal equilibrium and can only be isothermal transiently (and then move on to some other thermal profile)”? This would be odd, since “thermal equilibrium” is not transient — it is the stable state that systems tend toward.

    “once thermodynamic equilibrium max. entropy is achieved in time, there is no free energy & get heat death …
    OK. Entropy generally increases when heat flows from warm to cool, so entropy can increase when heat flows from the cool top of a column of air to the warm bottom. Once that temperature gradient is removed, then we have reached the “heat death” of that column of air.

    “What part of Poisson eqn. derivation do you disagree with?”
    I have no problem with the derivation — it accurately describes the situation where a parcel of air is moved
    adiabatically from one altitude to another. But since this (by definition) means the parcel cannot exchange heat with the surroundings, this means that the system can never allow the flow of heat to move toward true equilibrium.

    As Kristian reiterated, the earth is never close to equilibrium, and the adiabatic lapse rate is the de facto “normal” for earth, but it is NOT “thermodynamic equilibrium”.

  86. Max™ says:

    Total energy remains fixed in a closed column of gas in a gravity well.

    Kinetic energy decreases towards the top of the column while potential energy increases.

    Temperature is a measure of averaged kinetic energy.

    If the averaged kinetic energy at all altitudes was the same, the total energy at the top would be much higher than that at the bottom.

    ________

    Thermodynamic equilibrium implies potentials are the same everywhere, does it not?

    How would one do that with gravitational potential?

  87. gbaikie says:

    “What is relevant is whether a system like our (Sun-)surface-atmosphere will ever reach such a state of equilibrium. Theoretical concept versus real world situation.”

    It can’t simply because there is a day and night.
    Adding a massive amount of atmosphere, like Venus [or gas giants] gets closer.

  88. Trick says:

    “DC: Trick I long since gave up on trying to follow your convoluted explanations. Sorry!”

    Well, DC expressed some hope of follow-up with numbers. However DC got lost in the numbers, writing I’m not lucid enough for DC so I dropped them.

    This stuff is simple but not easy DC. Thermo is convoluted by nature’s design and DC made one of the best starts I’ve seen in Part 1.

    Your top post Part 2 has hardly any furtherance of the science & so wordy/convoluted I don’t follow all of it either, so I research stuff on my own. Ask questions for clarification, it is a talkshop. Where do I make DC lose track exactly? Or just research a good text book from which I’m condensing poorly. I again recommend Bohren or Wallace&Hobbs. Or even on line with Caballero text.

    I’ll admit I try to induce some interest in looking basic stuff up on your part. Just what is Poisson eqn.? It is straight from conservation of column energy (as Max 2:17am implies) setting dq=0. What’s that mean? (Means adiabatic, no small quantity of heat added to unit mass of material.) Just what is heat eqn.? Both should prove interesting and applicable. And Part 2 could benefit from your research of that theory.

    Help me; cite a ref. on atm. column effective conductivity throughput throttling. I’ll go dig into it.

    ******

    Kristian 12:05am – Have to consider whether real world or theoretical system is forced or unforced equilibrium also.

    ******

    Tim F. 1:54am: Interesting questions, more tomorrow. Need to refill my lucidity. Think about thermal equil. as same temp. throughout a solid or same temp. in no gravity gas but is not max. entropy for a gas in gravity field. Adding gravity potential changes a gas max. entropy point higher so need to invoke thermo. equil.

  89. Trick says:

    OK, can’t resist a little more now.

    Tim F. – “This would be odd, since “thermal equilibrium” is not transient — it is the stable state that systems tend toward.”

    Like many, this is thinking from a solid point of view. Yes, solids are ok to use “thermal equilibrium” in a bar of iron b/c the molecules are fixed in the lattice – they can’t move in the gravity field (not much anyway).

    But in a gas in gravity well you have to think more complex thermodynamic equilibrium b/c the molecules move around so that their mgh (PE) changes cannot be ignored (this is the “potentials” Max discusses). I offer this as a cite from Bohren: The Fourier conduction “law” for solids and fluids is misnamed a “law” b/c it is not strictly applicable to gases where PV=nRT becomes important also.

    Because of the gravity “potentials” (Max term) a gas originally in thermal equilibrium will find an even higher max. entropy in thermodynamic equilibrium when gravity turned on. Caballero discusses this in detail with pictures.

    ******

    Seems like we agree on heat death for an adiabatic column and the universe.

    ******

    Poisson eqn. – “But since this (by definition) means the parcel cannot exchange heat with the surroundings, this means that the system can never allow the flow of heat to move toward true equilibrium.”

    Can’t exchange heat with the surroundings, right. But each parcel IN the column can exchange heat with other parcels IN the column until heat death occurs. At that point, get max. entropy and Poisson eqn. shows exact lapse rate under the ideal conditions off from observed lapse about 10%. Lapse of g/Cp is a worse approximation, off ~20% from observed lapse up thru tropopause.

    Kristian is right of course, the real world never reaches thermodynamic equilibrium as it is forced; entropy therefore is not strictly applicable but the concept is still useful. And even calculable if say assume standard atm. P&T profile and integrate numerically over say 10,000 slices with a computer as they did in Verkley paper.

  90. Trick
    Tim F
    and ALL

    I ask you as politely as I can muster to please desist from discussing the ‘gravity well/Loschmidt’ issue. It has little to do with the topic under discussion here which is…

    So what kind of heat flow throttling do you favour?

    …and, even if it did, that issue was NOT resolved before so it is unlikely it will be resolved now. Trick and one or two others did it to death elsewhere many months ago over hundreds of comments, with no ultimate agreement, and with the consequence that almost everyone else withdrew from that thread.

    Thanks for your cooperation. 🙂

    DC

  91. Stephen Wilde says:

    “So what kind of heat flow throttling do you favour?”

    Compositional changes attempt to create output throttling but volume and circulation changes negate it via throughput throttling.

  92. Stephen Wilde says, February 21, 2013 at 9:29 pm

    Stephen,

    Between us, I definitely think we are getting somewhere very interesting. It would also be good to have Tim F’s input, and that of others, if we can drag them away from Loschmidt. 🙂

    I agree with every word you say in your particularly careful and lucid explanation above. But I would like to explore more deeply the mechanism that pulls the earth back to equilibrium, centered around what you call the lapse rate set by gravity.

    Since we are talking here of a model atmosphere, where all the energy flows are averaged out for the planet as a whole, it is perfectly reasonable for us to talk also about a corresponding average lapse rate. The question we need to resolve is whether your ‘lapse rate set by gravity’ and my ‘average lapse rate’ are actually the same thing. I think they are.

    Well my ‘average lapse rate’ is simply the lapse rate that would occur if there were no weather and no dynamic changes such as the diurnal cycle (there is neither in my model, by definition). Yes, this is a very theoretical idea (all models are!) but I think it leads to a very practical conclusion, so please bear with me.

    In such a model it follows that the ‘average lapse rate’ is the only lapse rate. So what is its likely exact value? I suggest that for earth as currently constituted the best estimate we have for the ‘average lapse rate’ is 6.5degC/km. This you will immediately recognise as the US Standard Atmosphere lapse rate figure.

    Now I agree it is unlikely that a Standards Organisation would have got the figure exactly right, but it doesn’t have to be exactly right. It just needs to be in the right ball park for the purposes of our discussion here. And 6.5degC/km does seem nicely positioned between the two theoretically calculated lapse rates, the dry adiabatic at 9.8degC/km and the saturated adiabatic at 5degC/km – just where commonsense would lead us to expect it to be, since the atmosphere is obviously (on global average) somewhere between these states of dryness and wetness.

    So what is my ‘average lapse rate’ actually determined by?

    Insolation, Cp of air, and pressure

    And what is your ‘lapse rate set by gravity’ actually determined by?

    Insolation, Cp of air, and pressure

    And although neither of us knows exactly how the atmosphere works in all its fluid dynamical details (but neither does anybody else I would suggest), we can still agree pragmatically that it does have such an average lapse rate; and that the current best estimate we have for it is 6.5degC/km.

    Now if 6.5degC/km is the critical threshold lapse rate for the atmosphere as a whole, at or below which there is no convection, and if an actual perturbation in the real atmosphere locally raises it above that level, causing convection (and, thereby, an ‘effective conductivity’ that is 1000 times higher than it is at or below that level) we have the perfect highly-non-linear feedback mechanism to keep the earth system in check at that precise critical lapse rate value.

    In which case we have found ‘earth’s thermostat’.

    DC

  93. Max™ says:

    Note: I mean chemical and thermal potential as well as gravitational.

  94. Max™ says:

    It is related to throughput, by the way, because the difference between an isentropic state and the current state dictates how rapidly energy will flow through the system.

  95. Stephen Wilde says:

    David.

    I agree that there is only one lapse rate if one takes the atmosphere as a whole. It is set by gravity and must be met long term if an atmosphere is to be maintained.

    One can call it the average lapse rate or the lapse rate set by gravity. I agree that we are talking about the same thing.

    I suspect however that it is closer to the dry air lapse rate than the Standard Atmosphere lapse rate because the latter is limited to the troposphere and heavily affected by water vapour whereas the true average lapse rate has to apply to the entire atmosphere from top to bottom all around the sphere.

    Otherwise what you say is perfectly correct. Whatever that average lapse rate set by gravity may be it is THE critical threshold and ANY local deviation from it must be corrected for elsewhere within the atmospheric circulation otherwise the atmosphere will be lost.

    Changes in effective conductivity are a good way of looking at it. Due to the pressure gradient and the three dimensional atmosphere being open to space the ‘drain’ is supremely effective and instantly responsive. The time scale for the equilibrium response only being limited by the speed of any necessary circulation changes which are mechanical rather than radiative processes.

    The negative system response is so sensitive because not only does pressure reduce with height but as part of that phenomenon the volume of each successive layer as one goes up increases enormously due to the three dimensional geometry of the atmosphere.

    The result is effectively no resistance to any redistribution of existing energy within the atmosphere. The circulation simply reconfigures with no need for any increase in equilibrium temperature.

    One has to actually increase the amount of energy coming in to get an increase in equilibrium temperature or increase mass or gravity.

    Nothing else can do it.

    The non linear feedback is provided by decreasing pressure plus increasing volume with height. The power of the negative system response is logarithmic because the decline in pressure and increase in volume with height are also logarithmic due to three dimensional geometry. That brings wayne’s comments about degrees of freedom into play.

    There is simply no additional resistance to the throughput of energy from radiative characteristics of constituent molecules and therefore no increase in equilibrium temperature.

    Strange that I always though that this was all common knowledge and settled science but apparently not.

  96. Tim Folkerts says:

    One last post on thermodynamics, and then back to David’s original idea.

    Trick said: “Can’t exchange heat with the surroundings, right. But each parcel IN the column can exchange heat with other parcels IN the column until heat death occurs.
    No. Here are a few references that I ran across with a quick web serach …
    “Because the parcel was lifted without adding heat, … ” http://san.hufs.ac.kr/~gwlee/session3/potential.html
    “Potential Temperature (θ)-the temperature an air parcel would have if it were expanded or compressed adiabatically from its existing pressure and temperature to a standard pressure
    p0 (=1000 hPa). http://atoc.colorado.edu/~cassano/atoc5050/Lecture_Notes/wh_ch3_part2.pdf
    “The term adiabatic means that no heat transfer occurs into or out of the parcel. Air has low thermal conductivity, and the bodies of air involved are very large, so transfer of heat by conduction is negligibly small.” http://en.wikipedia.org/wiki/Lapse_rate#Dry_adiabatic_lapse_rate

    Each of these is very clear that “adiabatic” is applied to the parcels individually, not just to the container as a whole.

  97. Trick says:

    David 7:51am: “the ‘gravity well/Loschmidt’ issue…has little to do with the topic under discussion here which is…So what kind of heat flow throttling do you favour?”

    There is an implicit gravity well in Fig. 5 so it is important to discuss how gravity potential (and even Max’ chemical potential) works for “heat flow throttling” even if gravity vector not shown explicitly. Is there a reason why David doesn’t show gravity explicit in Fig. 5?

    Whatever Loschmidt issue is other than the Loschmidt number (=Avogadro number), Loschmidt is not mentioned or explained in top post or in the text books so I may trip across it w/o knowing. I agree with Max 10:06am too, that knowing the isentropic state and the current observed state allows a clue for how rapidly energy flows thru system.

    My favored guess for what David means by “heat flow throttling” is the atm. gas processes of conduction, convection and radiation which all are defined mathematically & act on the m^2 heat flow in forced equilibrium shown in Fig. 5 top post. All should be fair game on topic for discussion, right?

    Top post: “The earth’s surface radiates energy at an enhanced rate (356Wm-2) towards the Base of the Atmosphere. At the same time, the lowest part of the atmosphere radiates energy at an enhanced rate (333Wm-2) towards the surface.”

    “So what kind of heat flow throttling do you favour?”

    My favour for “heat flow throttling” is I happen to understand Stephen’s explanation of the adiabatic loop (the 17 thermals and the 80 latent shown in Fig. 5) and Stephen’s diabatic loop (the 78 insolation in Fig. 5 and 157 balance of atm. body radiation toward surface body not shown plus the 1 missing shown implicitly) all adding up to the 333 toward the surface which Trenberth doesn’t break down.

    Also, I note, not yet discussed is the 1 Trenberthian missing heat shown in Fig. 5 continuously warming the surface (L&O) where 161 SW is shown into surface but only 160 LW out (40+80+17+23). Interesting.

  98. Stephen Wilde says:

    Tim Folkerts said:

    “The net result is that the average KE stays the same as you go up!”

    Then why is the temperature lower with height ?

    Temperature is a measure of KE isn’t it ?

    I don’t think your suggestion stacks up due to the fact that you (and all other radiative only proponents) ignore mechanical pressure effects on temperature (and thus KE).

    [Reply] Because the usual conflation between the temperature of individual molecules and the properties of bulk gases is obscuring the issue, which as David has pointed out has been dealt with at length elsewhere, and no doubt will be again. So can we please drop it for now and return to the topic, as per David’s request. – Thanks – TB.

  99. Trick says:

    Tim F. 2:19pm – Thanks for the links, I looked & believe they are perfectly on topic. David may not but still he (and tb) is a learning machine. The first one, in part, shows why I favour “heat flow throttling” as combination of all 3 processes:

    “If we were to lift a volume of that air (without adding any heat to the air)…”

    Well, that 1st site listed gets a time out to go and study what adiabatic container discussed in top post & Part 1 really means. They can’t “reach in” and lift the air, right? The air is lifted by free energy already IN the column. When all that free energy is used up (heat death at max. entropy), the Poisson lapse shown is the result and is steady LTE, no more bobbing air parcels since not enough free energy w/o reaching in. dq=0 is subtle, no “reaching in” allowed.

    The second link shows derivation of Poisson eqn. an adiabatic process 10% off from observed lapse with potential temperature conserved yet shows a non-isothermal lapse ascending with pressure reduction! OMG non-isothermal!

    Study that. It is exactly what I wrote (poorly, I know David). Capture a parcel at top at cooler temperature, bring it to surface, find higher temperature with NO HEAT EXCHANGE from other parcels b/c of heat death already assumed existing – meaning adiabatic bring to surface process. Cool huh? (well, except for the virtual bring to surface reach in again). Tim’s thermal equil. iron bar theory is the temperature at top is equal to potential temp. at bottom. Not so in a gas, need thermodynamic equilibrium of Poisson eqn. lapse shown therein when gravity exists.

    The third link is a slightly different context than Poisson, it is (shortened for brevity) deriving the approx. g/Cp lapse – the one that is 20% off from observed. The reasons that it is off so much from observed is 1) the assumption of constant temperature so the integration dT/dz can proceed to get a constant g/Cp and 2) no forcing. That’s why Poisson eqn. lapse is much closer to observed since in Poisson the integration of T proceeds as a variable T.

    In the third link case cannot conclude “Temp. is same at top and bottom” simply b/c that is what is 1st assumed (i.e. the simplifying assumption cannot be a conclusion.)

  100. Stephen,

    Looks like good progress. Can we now please clear up some hopefully terminological issues so that everyone has a clear understanding:

    (1) You say: I agree that there is only one lapse rate if one takes the atmosphere as a whole. It is set by gravity and must be met long term if an atmosphere is to be maintained.

    Can you just confirm that you agree that the lapse rate we are now both talking about is set by three things not one: gravity; CP of air; and insolation. Otherwise we are not in agreement! (You wouldn’t have a lapse rate if Cp=0; and you wouldn’t have a lapse rate if insolation was 0, as I elaborated in my previous comment at February 21, 2013 at 8:07 pm)

    (2) You say: Whatever that average lapse rate set by gravity may be it is THE critical threshold and ANY local deviation from it must be corrected for elsewhere within the atmospheric circulation otherwise the atmosphere will be lost.

    Elsewhere? In terms of my model, as soon as the lapse rate is exceeded within a local atmospheric column, energy escapes with 1000 fold efficiency straight up within that same column. (Of course I appreciate in the real atmosphere there may be all sorts of turbulent effects and horizontal circulations going on but that is what I have rigorously tried to factor out with my model which has no ‘weather’.)

    (3) You say: Changes in effective conductivity are a good way of looking at it. Due to the pressure gradient and the three dimensional atmosphere being open to space the ‘drain’ is supremely effective and instantly responsive. The time scale for the equilibrium response only being limited by the speed of any necessary circulation changes which are mechanical rather than radiative processes.

    Again, I don’t disagree that that is what happens in the real atmosphere. I think what you are saying is that heat from one particular hot area can in principle rise up and be spread all over the globe to be released anywhere at the ToA. But just be aware that in my model, the atmospheric column is essentially one dimensional – up and down.

    (4) You say: The negative system response is so sensitive because not only does pressure reduce with height but as part of that phenomenon the volume of each successive layer as one goes up increases enormously due to the three dimensional geometry of the atmosphere.

    That statement I don’t really understand. First of all, when you refer to “negative system response” are you referring to my comment at February 22, 2013 at 9:41 am: “highly-non-linear feedback mechanism to keep the earth system in check” ? My feedback mechanism works when the local lapse rate begins to rise above the average lapse rate. Convection immediately begins, increasing upward flow of energy to space by 1000 fold, thus preventing the rise from continuing.

    Also, I don’t understand how the “volume of each sucessive layer” increases. Surely one conventionally takes equal height slices when discussing the atmosphere, so all my slices by definition have the same height and therefore the same volume. Or are you just referring again to the sideways spread of energy in the real atmosphere (as opposed to my model)?

    (5) You say: The non linear feedback is provided by decreasing pressure plus increasing volume with height. The power of the negative system response is logarithmic because the decline in pressure and increase in volume with height are also logarithmic due to three dimensional geometry. That brings wayne’s comments about degrees of freedom into play.

    Again are you talking about my negative feedback effect due to the local lapse rate beginning to rise above the average lapse rate, as discussed in (4) above? If so, I don’t think my negative response is logarithmic. I think it’s more like exponential! My remarks in (4) about equi-volume slices also apply here. And I also don’t understand how Wayne’s comments about degrees of freedom come into my proposed ‘earth’s thermostat’ mechanism.

    Sorry the above is so very detailed and may seem a bit nit picking but I think we are so much on the right track that I don’t want us to come off the rails!

    DC

  101. Tim Folkerts says:

    Stephen I am not a “radiative only proponent”! And I doubt you will find many such people around (at least among those who have given serious thought to the issues). Yes, radiation is the ultimate key to earth’s temperature, since energy arrives at earth as radiation (from the sun) and leaves as radiation (thermal IR). But the warming effects between the TOA and the surface require knowledge of the bulk properties of the atmosphere.

    The “greenhouse effect” always includes both …
    1) a radiative component (which could be called “output throttling” which blocks the “warm, bright IR” from the surface)
    2) and a bulk component (which could be called “throughput throttling”, which separates the IR radiators from the surface).

    Or we could say it another way. The effective black body temperature of the earth is 255 K. As long as the albedo doesn’t change, the effective black body temperature will remain 255 K. If some of that radiation escapes to space from regions above the surface where it is cooler than the surface (due to the lapse rate), then the radiation from the surface must be above 255 K to make up the difference. It is perhaps too obvious, but for thermal IR radiation to escape to space from above the surface, there there must be materials that can emit IR located above the surface (the “blocking” radiate component and the “spacer” effect of the bulk of the atmosphere). The more more atmosphere there is, the higher the GHGs and clouds will be (ie the main difference between earth & Venus). The more GHGs there are, the higher they will be in a given atmosphere (ie the main difference between earth with 350 ppm CO2 and earth with 400 ppm CO2) .

  102. gbaikie says:

    “So what is my ‘average lapse rate’ actually determined by?

    Insolation, Cp of air, and pressure

    And what is your ‘lapse rate set by gravity’ actually determined by?

    Insolation, Cp of air, and pressure”

    “In which case we have found ‘earth’s thermostat’.”

    Which translates to sunlight and water.

    As gravity is constant. Cp of atmosphere gases is around 1.
    And water vapor almost 2. And liquid water is about 4

    And since sunlight can also be seen as constant.

    Water is the thermostat.

    Which there is broad agreement.

    Or the way CO2 is seen as particularly significant is
    it is thought to change the amount vapor in atmosphere.

    But just because there is much agreement, it doesn’t mean it is correct-
    though perhaps something about it, is correct.

    A problem as I see it, is the focus on atmosphere which more about
    an effect, rather than a cause.
    More symptom than the cause.

    It begins with the sunlight interacting with a surface.

    And with Earth, most of the surface is ocean.
    And it is well known that the ocean traps an enormous
    amount of heat.

    Another surface on Earth is the clouds [an “ocean” of droplets
    of water], and another is land surfaces.

    With Venus, a significant surface- in terms it’s relation to
    sunlight- is it’s clouds [mostly comprised of droplets of sulfuric acid].

  103. Stephen Wilde says:

    David, you are making me work hard and I think much of that is covered in my earlier stuff but here goes:

    (1) Mass sets the starting point at the surface for the temperature decline with height. Insolation sets the height that an atmosphere can reach. Gravity sets the slope. Obviously all three are interdependent but the strength of the gravitational field sets the slope that will develop for a given amount of mass and given level of insolation. If one changes the strength of the gravitational field without altering mass or insolation the slope will be steeper for a stronger field (low compact hotter atmosphere)and shallower for a weaker field (higher more diffuse cooler atmosphere).

    (2) The distortion of the lapse rate caused by water vapour in the troposphere and the opposite distortion caused by ozone in the stratosphere are not dealt with in those layers but could be said to be dealt with in the rest of the vertical column right up to top of atmosphere so your highly idealised model is correct in its own terms.

    (3) Agreed in principle for an idealised model such as yours.

    (4) I’m referring to the lateral increase in size which is only fully realised around a sphere. A 1 metre deep shell around the Earth just above the surface has a much smaller volume than a 1 metre deep shell around the Earth at 1000 metres height.

    I’m not sure what you mean by ‘preventing the rise from continuing’. The only thing that prevents the rise from continuing is the reversed lapse rate at the tropopause. Without that it could keep going to top of atmosphere like a bubble of vapour from the bottom of a boiling saucepan to the top of the water within it.

    (5) I may have misunderstood some aspect of your proposed negative response because I thought my comments were consistent with it. Perhaps I used the term ‘logarithmic’ incorrectly because I think the term ‘exponential’ is suitable too. Either way it is far more powerful than a linear system response. Wayne’s degrees of freedom come in because the higher one goes the smaller the surface becomes in the field of view of a molecule and so the more likely is its energy to leave the atmosphere or simply be transferred within the atmosphere rather than being returned to the surface. Therefore there is an upward bias in the degrees of freedom for energy leaving a molecule

    Note that convection is itself the corrective mechanism and will fizzle out naturally when balance is regained. One doesn’t need a further negative response to that convection.

    I think we are very close so it is good to iron out the terminology and potential misunderstandings.

  104. Stephen Wilde says:

    Tim.

    Sorry if I failed to appreciate the subtleties of your position.

    I agree that there is a combination of output and throughput throttling.

    Our difference seems to be that you think GHGs lead to a higher equilibrium temperature whereas I think they do not.

    Only more mass, more gravity or more incoming energy lead to a higher equilibrium temperature.

  105. Tim Folkerts says:

    Stephen says: “Only more mass, more gravity or more incoming energy lead to a higher equilibrium temperature.”

    How can you leave “outgoing energy” off the list? Surely less outgoing energy would raise the temperature of the earth just as effectively as more incoming energy. And surely outgoing energy is (at least in part) determined by radiation from GHGs.

  106. Bryan says:

    Tim Folkerts says that convection is a necessary condition for the DALR.
    On this planet this is certainly not true.

    The DALR atmosphere is also called the Neutral Atmosphere.
    This occurs when there is very little or no vertical convection.
    This occurs quite naturally, often at night.

    So under these conditions if two thermometers were placed one kilometer vertically apart, the upper one would read about 9.6K less than the lower one.

  107. tallbloke says:

    Bryan, timely observation. Particularly true of the bulk of the troposphere from say 1km up.

  108. Stephen Wilde says, February 22, 2013 at 5:05 pm

    Stephen,

    Thanks for your continuing responses. We really are getting somewhere now I think.

    We are throught the hoop on (1), (2) and (3).

    On (4), I have two comments:

    Firstly I think you have simply made a mistake concerning the geometry of the earth and its atmosphere. The earth’s radius is 6371km. The radius of a spherical shell at 10km height above the earth’s surface is therefore 6381km. So 1 square metre on the earth’s surface becomes 1 x (6381/6371)^2 = 1.003 square metres at 10km. A negligible difference.

    Secondly, where I said ‘Convection immediately begins, increasing upward flow of energy to space by 1000 fold, thus preventing the rise from continuing’, I meant preventing the rise in the lapse rate from continuing, not the rise in the physical parcel of air winging its way up to the tropopause. Apologies for my ambiguity!

    On (5), I also have two comments:

    Firstly: A logarithmic increase would be a declining rate of rise of output corresponding to a linear rising input. An exponential increase would be an increasing rate of rise of output corresponding to a linear rising input. (A linear increase would of course be a linear rise of output in response to a linear rising of input.)

    Secondly, regarding the size of the field of view of the surface from 10km, it is almost the same as from ground level, for the same kind of geometrical reason as discussed in (4) above (but the geometry is a bit more complex). So Wayne’s degrees of freedom would not enter into what we are discussing, if they are dependent on the field of view changing significantly.

    DC

  109. Tim Folkerts says:

    Bryan, I don’t have time to check everything i have written, but I would be surprised if I said “convection is a necessary condition for the DALR.” Could you indicate specifically what you are referring to so I might know how to respond?

  110. Bryan says:

    Tim Folkerts says in two quotes;

    1.
    “Instead, convection gives the atmosphere a LAPSE RATE, with a conductivity that increases when the throughput increases, maintaining a constant temperature difference REGARDLESS of the throughput. (Yes, the throughput makes a bit of a difference in the lapse rate, but really not very much I suspect. The one exception I can think of off-hand would be with a “negative throughput” that might occur at night and create an inversion.)David, how about “Convection gives AN UPPER LIMIT TO the lapse rate” ? ”

    2.
    “Or stated another way, WITHOUT convection there could be pretty much any lapse rate, depending on the throughput. WITH convection, the lapse rate is capped at ~ 6.5 K (for moist, condensing air, or ~10 K for dry, non-condensing air).”

    The condition for DALR is hydrostatic equilibrium.
    This condition is not unstable as some folk think.

    When it occurs (the neutral atmosphere it is stable for extended time periods.
    Convection occurs on the other hand is when the air parcel is not in hydrostatic equilibrium.

    If I have taken the wrong meaning from the above quotes perhaps you can set the record straight .

  111. Tim Folkerts says, February 22, 2013 at 5:51 pm: Stephen says: “Only more mass, more gravity or more incoming energy lead to a higher equilibrium temperature.” How can you leave “outgoing energy” off the list? Surely less outgoing energy would raise the temperature of the earth just as effectively as more incoming energy. And surely outgoing energy is (at least in part) determined by radiation from GHGs.

    How could one leave outgoing energy off the list? Very easily, Tim, because input energy = output energy, unless that is you are playing the cup and pea game. The only way to have a coherent discussion about climate is to talk steady state. As soon as you assume that input energy does NOT equal output energy you are into a transient situation where anybody can prove anything and everybody gets very muddled.

    But perhaps you intended that?

    DC

  112. Tim Folkerts says:

    Stephen>> 1) Mass sets the starting point at the surface for the temperature decline with height. Insolation sets the height that an atmosphere can reach. Gravity sets the slope.

    David >> We are through the hoop on (1), (2) and (3) …

    Are we even through Hoop 1?

    Insolation (along with albedo) sets the starting temperature (255 K). Not mass!
    Gravity (along with heat capacity) sets the slope.
    Mass sets the height that the atmosphere will reach.
    GHGs (along with the above) set the altitude where the temperature will be 255 K.
    The lapse rate (along with all of the above) sets the surface temperature.

  113. Tim Folkerts says:

    Bryan, I think we are close, but not 100% on the same page here. Part of it has to do with the “environmental lapse rate” (experimental) vs “adiabatic lapse rate” (theoretical). Let me take one more stab at an explanation.

    “The condition for DALR is hydrostatic equilibrium.
    A second condition is that a parcel of air that moves adiabatically up or down will be at the same temperature as the surrounding atmosphere. There are many (infinite) other profiles that would be in hydrostatic equilibrium. The ALR is a theoretical result — a model that it pretty close to the actual atmosphere is some cases.

    “This condition is not unstable as some folk think.
    The theoretical ALR is perfectly stable – no energy transfer and no movement of air.
    The actual ELR is OFTEN stable and often is close to the ALR. One of the main reasons that the ELR is often close to the ALR is convection. If there is even a tiny net flow of energy upward, then the air will convect, which can carry large amounts of energy upward. This will remove energy from the warm surface, cooling it (and add energy to the cool air above, warming it), thereby reducing the ELR back toward the ALR.

    So the AIR might be unstable (when the surface is being heated), but the LAPSE RATE is rather stable.

    Or stated another way, convection is like a “pop-off valve” which kicks in once the ELR > ALR.

  114. Trick says:

    David 11:17pm: “How could one leave outgoing energy off the list? Very easily, Tim, because input energy = output energy…”

    Well, yes of course in=out at LTE & David in top post wrote correctly and then expanding RHS:

    “…earth’s surface radiates energy at an enhanced rate (356Wm-2) towards the Base of the Atmosphere. At the same time, the lowest part of the atmosphere radiates energy at an enhanced rate (333Wm-2) towards the surface.”

    Input energy = (Output from surface energy – atm. towards surface energy) W/m^2

    Clearly the atm. throttles whether favor throughput or output. The throttle varies the near surface temp. since as Tim F. points out as the “atm. towards surface” increases then surface T goes up & increases “output from surface” to keep in balance with “Input energy”.

    Simple not easy. Stephen even made this same “clarify” point once before.

  115. Tim Folkerts says:

    David says: “The only way to have a coherent discussion about climate is to talk steady state. “.

    I was not trying to play any sort of game, only to say (once again) that “output throttling” is an important factor and influences the output power.

    Certainly output = input in steady-state. The “output throttling” (radiation to space from clouds & GHGs) helps determine that steady-state conditions. Stephen seemed to be saying that ONLY mass, gravity, and insolation mattered.

    So maybe I’ll ask you. Do you think that ONLY mass, gravity, and insolation matter? Could I replace the atmosphere with an equal mass of pure N2 or pure CO2 or pure Ar and get the same temperature as we have now at the surface (assuming I could keep the same albedo)?

  116. donald penman says:

    I think that the Earth is not a machine and it does not have a thermostat ,your model only leads to this conclusion because of the assumptions you have made in constructing that model.Space is not an insulator energy can flow to space, objects tend to keep moving with a constant velocity because there is little to stop this movement in space.If we are not forced to think of the earth as a machine then other important aspects of the atmosphere which are not apparent in your model become clear to us,an atmosphere gives us a local thermal equilibrium which we would not have in space caused by the constant random motion of molecules in the atmosphere. local thermal equilibrium allows the part of our body that is in being irradiated by sunlight to acquire the same temperature as the part of our body in direct sunlight, to get the same effect in space then spaceships have to rotate with respect to an energy source ,having an atmosphere then gives us this benefit.Clearly there is resistance to energy flow in an atmosphere both physical and radiative but as the atmosphere becomes more like space then this resistance becomes less.

  117. Kristian says:

    Tim, you say: “Insolation (along with albedo) sets the starting temperature (255 K). Not mass!” and “GHGs (along with the above) set the altitude where the temperature will be 255 K. The lapse rate (along with all of the above) sets the surface temperature.”

    No. You’ve got it all turned upside down.

    You can not deduce the temperature at any one level in the troposphere from just looking at the insolation at that same level.

    240 W/m^2 flow down from the Sun through TOA on average. Here, at the tropopause, where convection ends and the tropospheric lapse rate profile starts (going down)*, the mean global temperature is 205-210K (which by way of the S-B equation should account for an energy flux of 100-110 W/m^2). Extrapolated down (6,5 K/km x 12,5 km), this gives a surface temperature of 288-289K. The level with a mean global temperature of 255K is simply to be found somewhere along this ladder (5+ km above the surface). But since of the 240 W/m^2 coming in at TOA only 165 W/m^2 on average reach the surface, the insolation at this 5 km level, in the middle of the convective troposphere, is surely not 240 W/m^2. This particular temperature level is rather controlled by the surface temperature and the lapse rate. Not the other way around.

    So,
    TOA: 207K, 240 W/m^2
    Theorised mean emission height: 255K, 195 W/m^2 (if flux is reduced linearly from TOA to BOA)
    Surface: 288K, 165 W/m^2

    *Of course the tropospheric temperature profile really has its starting point at the surface. Based on the insolation, the mass (the pressure exerted) and the density (the potential rate of molecular collisions -> KE) of the atmosphere above it, the surface temperature is set. This temperature is needed to adequately drive convection, transporting the absorbed heat as high up from he surface as gravity allows. This level is the tropopause, and here the heat is finally dumped and radiated off back to space.

  118. Stephen Wilde says:

    Tim.

    Only mass and gravity determine the proportion of insolation that an atmosphere can retain.

    If anything else changes then the circulation adapts appropriately.

  119. Stephen Wilde says:

    David.

    Points 4 and 5 aren’t really essential. We both agree that the negative system response is strong enough to avoid all forcing elements other than mass gravity and insolation from affecting equilibrium temperature.

    Explanations as to why that is so and how it is achieved are bound to be varied and disputed.

  120. Stephen Wilde says:

    Tim said:

    (i) “Insolation (along with albedo) sets the starting temperature (255 K). Not mass!”

    If there is no atmosphere then insolation and albedo set the surface temperature. As soon as one adds mass in an atmosphere it begins to raise the average global temperature above the mid way point between the day and night sides. The more mass the higher the temperature.

    (ii) “Gravity (along with heat capacity) sets the slope.”

    Please indicate how heat capacity alters the slope given that circulation changes would negate the effect of heat capacity.

    (iii) “Mass sets the height that the atmosphere will reach.”

    Without insolation there would be no gaseous atmosphere. All the molecules would form a solid on the ground. Insolation lifts the molecules off the ground and the more insolation the higher they rise.

    (iv) “GHGs (along with the above) set the altitude where the temperature will be 255 K.”

    Changing that altitude alters the throughput of energy which cancels out the effects of GHGs. The entire atmosphere expands and contracts which speeds up or slows down the rate of throughput.

    (v) “The lapse rate (along with all of the above) sets the surface temperature.”

    The ideal lapse rate is a result of declining pressure with height which does not in itself set surface temperature. The rate of decline of pressure with height is set purely by the strength of the gravitational field. It must be measured from the location of maximum pressure at the surface. It is not correct to take a so called effective radiating height within a single layer part way up the atmospheric column and then project that back to the surface to get surface temperature.

    The ideal lapse rate must be measured from surface right up to top of the atmosphere because many factors can distort the ideal lapse rate in different layers between surface and space so that the real world lapse rate below the so called effective radiating height will often differ from the ideal lapse rate.

    Ozone in the stratosphere actually reverses the lapse rate as does solar heating of molecules in the thermosphere.

  121. gbaikie says:

    ” Tim Folkerts says:
    February 22, 2013 at 5:51 pm

    Stephen says: “Only more mass, more gravity or more incoming energy lead to a higher equilibrium temperature.”

    How can you leave “outgoing energy” off the list? Surely less outgoing energy would raise the temperature of the earth just as effectively as more incoming energy. And surely outgoing energy is (at least in part) determined by radiation from GHGs.”

    An actual greenhouse is not like the greenhouse effect- an actual greenhouse works by preventing the convection of air. But let’s look at actual greenhouses and ask the question
    would they increase the average temperature of a planet?

    At first blush, it seems very obvious that actual greenhouse would increase the average temperature of the planet. A greenhouse allows one to grow tropical plants in a temperate
    zone- it reduces the chance of getting freezing temperatures and these freezing temperatures
    will kill tropical plants. And if measure the temperature inside a greenhouse, you can see a very dramatic increase in average yearly temperature. And such dramatic increase will occur in temperate zones. Less useful in tropical areas or polar regions- unless in tropical zone one in region where one gets freezing nights and polar regions in winter are going to freezing nites [and days] despite having a greenhouse.
    But a greenhouse could add say 20 C to average yearly temperature in certain areas- have a very dramatic effect.

    Lot’s of people own and have cars, and cars can function like an actual greenhouse. If you parked a car somewhere and measured it’s annual average temperature, it like a greenhouse could have a dramatic increase in annual average temperature.
    But over the years, cars or greenhouses don’t get ever increasing annual average temperatures- a 10 year old greenhouse isn’t significantly warmer than a 1 year old greenhouse.

    In terms of the average temperature of Earth, it’s all about tropical ocean temperature. Having a very large region with average yearly temperature of 25 C, is the reason Earth has an average temperature of about 15 C.
    So if you put greenhouse at the equator, had the floor of greenhouse be the ocean water, are you going to have increase in average temperature inside the greenhouse?
    It doesn’t seem to me that it would have significant difference- and one would not see such dramatic increases in average yearly temperatures, as you would see in temperate zones.

    A finally if you had a few zillion greenhouses in a temperate zone, would the greenhouse add to the average temperature of this temperature zone?
    Inside the greenhouses certainly one see a difference, but I mean, do increase the temperature outside the greenhouses? Is not even possible that all these greenhouses reduce the average temperature in the temperature zone- they are trapping warm air which otherwise would add to general region- it would be a small effect if any, but main point is I don’t see them doing much to warm the region.

    And compared to say greening the Sahara desert- irrigation and adding some lakes- this would have noticeable effect on region.
    It should increase the regional average temperature- basically having warmer nights in the region and have affects beyond the region.
    By adding water to a desert, you will reduce daytime highs and increase night time temperature- because water vapor and water trap heat.

  122. clivebest says:

    Stephen,

    You replied to Tim as follows:
    “(iv) “GHGs (along with the above) set the altitude where the temperature will be 255 K.”
    Changing that altitude alters the throughput of energy which cancels out the effects of GHGs. The entire atmosphere expands and contracts which speeds up or slows down the rate of throughput.

    The entire atmosphere expanding and contracting is saying the same thing as it warming and cooling. So yes the rate of throughput increases and decreases in response to GHGs

    Tim,
    There is no real physical meaning to the 255K altitude. H2O and clouds radiate to space from varying heights in the atmosphere. CO2 however is very different. It radiates to space mostly from very high up in the atmosphere. It plays very little role in the thermodynamics of the bulk of the atmosphere – so-called throughput throttling, where convection and evaporation dominate. However, CO2 does play a role in “output throttling” together with other GHGs (particularly H2O).

    I have spent the last week actually calculating emission heights for all lines in the 15 micron CO2 band, using the HITRAN database. The results can be seen here.

    The main central lines in the spectra radiate way up in the stratosphere. Only the side band lines radiate in the troposphere. The effect of doubling CO2 indeed raises these altitudes. However, It turns out that heat loss actually increases in the stratosphere while it decreasing loss in the troposphere due to the side bands. The total effect is to decrease radiation slightly. You can read more about all this here. http://clivebest.com/blog/?p=4597

    The real signature for a CO2 GHG effect would be to observe cooling in the stratosphere. This is especially true as there is no significant water vapour there.

    If I had to answer the question as to which heat throttling mechanism to chose. I would say they are complementary. You can’t have one without the other !

  123. Stephen Wilde says:

    clive said:

    “The entire atmosphere expanding and contracting is saying the same thing as it (is) warming and cooling. So yes the rate of throughput increases and decreases in response to GHGs”

    If the atmosphere expands then the increase in height converts more KE to PE so if incoming energy stays the same the net effect would be no warming despite the expansion.

    If the atmosphere contracts then the decrease in height converts PE back to KE so if incoming energy stays the same the net effect would be no cooling despite the contraction.

    So you can have expansion without warming and contraction without cooling provided the change in volume is caused by something other than more mass, more gravity or more incoming energy.

    The AGW error is in assuming that expansion is a consequence of prior warming but it doesn’t need to be so. Instead the expansion can simply be a consequence of more PE in the atmosphere relative to KE

    There is just a faster adiabatic loop throwing surplus energy out faster so that it cannot alter equilibrium temperature and it is the faster adiabatic loop that pushes the heights up rather than a warmer surface.

    One doesn’t need a warmer surface to give a faster adiabatic loop either because all the necessary changes occur within the layers of the atmosphere and not at the surface.

    One can get regional temperature changes from the new global circulation but the overall energy content remains the same as before.

    Due to the decline in pressure with height, the temperature dependance on pressure and the top of atmosphere being open to space there is no additional resistance to energy throughput from a change in radiative characteristics alone.

    The expansion and contraction is what prevents warming or cooling of the system as a whole because it regulates throughput via its throttling effect.

    A given amount of mass and a given strength of gravitational field can only cause the retention of a fixed proportion of the energy arriving from any external source or sources. If anything else seeks to alter that equilibrium temperature then the volume of the atmosphere changes in order to regulate the energy throughput and it achieves that by juggling the ratios of KE and PE within the overall circulation.

    I’m unable to account for the remarkable stability of planetary temperatures and the long term retention of atmospheres any other way.

  124. Stephen Wilde says:

    “If I had to answer the question as to which heat throttling mechanism to chose. I would say they are complementary. You can’t have one without the other !”

    That seems to accord with my earlier comments.

    If it were not for output throttling there would be nothing to activate the mechanism for throughput throttling.

    So the question is whether they are equal and opposite.

    They cannot ever be of the same sign as proposaed by AGW theory because that results in an infinite positive feedback until the atmosphere is lost.

    They cannot be unequal for any extended period of time or we would observe a far more unstable atmosphere in the paleo record.

    Equal and opposite it must be.

  125. clivebest says:

    “So the question is whether they are equal and opposite.”.

    Yes they are equal and opposite. I think the Earth will always remains in energy balance.

    If it can cope with seasonal and orbital changes, then it can surely also cope with far smaller GHG changes.

    However there is no logical reason why any new atmospheric equilibrium should not result in a slightly warmer surface temperature. My gut feeling though is that temperatures won’t change very much because the oceans have always acted to stabilize the climate.

    I may be right or I may be wrong – but only let measurements decide. Never let ideology influence your judgement.

    So for example – searching for missing heat in the oceans is just a joke !

  126. Trouble is, just asserting that they are equal and opposite without providing convincing proof isn’t going to get us anywhere near agreement with warmists. Likewise, just asserting that they exactly ‘offset’ one another isn’t going to help either. One might just as well assert that “both throughput and output throttling are actually the same sign, both serving to reduce the rate of flow of energy to space”. These are all just assertions. None will help convince anyone who disagrees.

    I am afraid there is no way of avoiding delving down into the physics of what is going on in the atmosphere and establishing the quantitative impact of these various putative mechanisms. Over this weekend I have been looking into lapse rates in much more detail and am appalled by the sloppy explanations I have found. No wonder atmospheric science is so ambiguous and in such an incoherent mess. For example from some sources “dry adiabatic” means the air has no water in it. For others, it means that the air has any amount of water in it (including none) as long as it is not actually saturated. Then some use other adjectives like “moist” and “wet”. Likewise, the use of the term “environmental lapse rate” is very sloppy and it is often not explained clearly that the dry and saturated adiabatic rates apply to parcels of air and are not attributes of the atmosphere as a whole.

    No wonder climate science is making such little progress. Bit like weather forecasting, I guess. 🙂

    DC

  127. Stephen Wilde says:

    There is lots of evidence that the output throttling and throughput throttling are equal and opposite OVER TIME.

    Also output throttling is simply my diabatic loop and throughput throttling is simply my adiabatic loop.

    Additionally, the oceans are involved as part of the diabatic loop such that they introduce variations in the rate of energy release back to the air whereupon the adiabatic loop in the atmosphere adjusts its own speed to negate the effect from the oceans just as it also negates the effects of every other forcing element other than from changes in mass gravity or incoming energy.

    Naturally there are time lags in oceans and in air and so lots of variations around the mean which is what causes so much confusion because the lagging effects can be up to around 1000 to 1500 years if one includes the thermohaline circulation of trhe oceans .

    Just watch the movements of the global air circulation in response to forcing elements and you can see the negative system responses in action on all time scales.

    More energy coming out of the oceans during the positive Pacific Multidecadal Oscillation pushes the climate zones poleward and increases throughput.

    Less energy coming out of the oceans does the opposite.

    An active sun pulls the climate zones poleward allowing more sunlight into the oceans in the subtropics to warm the oceans thus favouring warming El Ninos over cooling La Ninas which leads to warmer higher latitudes.

    A quiet sun pushes the climate zones equatorward allowing less sunlight into the oceans in the subtropics so the oceans cool thus favouring La Ninas over El Ninos which leads to cooling higher latitudes.

    No doubt more GHGs have a similar effect but there is doubt as to whether their net sign is warming or cooling but either way it is infinitesimal compared to what sun and oceans do all the time.

    But whether warming or cooling it is all just variations around the mean set by mass gravity and insolation.

    The answer to the climate debate is noting and measuring the average positions sizes and intensities of the climate zones so that changes can then be linked more accurately to the available forcing elements.

    I agree with David about the sloppiness of the science as regards lapse rates. Previously I proposed cutting through it by adopting the term ‘ideal’ lapse rate for the theoretical one set by gravity and all others being ‘environmental’ or ‘real’ lapse rates.

    To absolutely prove my hypotheses will require much data of different types to that ever previously collected but in the meantime the poleward / equatorward shiftig of the climate zones plus the contraction and expansion of the atmosphere from solar and oceanic influences need only be observed for a decade or two to show that it must be so.

    I think we have enough prima facie evidence over the past century to put it beyond reasonable doubt once proper weight is attached to the observed changes in climate zone positioning and the behaviour of the jets.

    I am very satisfied that David’s rigorous analyses here leave my hypotheses fully intact and indeed tend to support them.

  128. Trick says:

    David 12:18pm: “…some use other adjectives like “moist” and “wet”.”

    Yeah, points out the trouble found using words not math from fundamental physics. The physics and math for the 2 lapse rate derivations (exact but ideal Poisson lapse eqn. Tim F. linked above & approx. g/Cp lapse) are precise enough though (off only 10-20% from observed). There is no condensing allowed in the parcel for g/Cp lapse or more exact Poisson lapse derivation physics&math so they use various imprecise words to convey the concepts unfortunately.

    Stephen’s adiabatic loop might increase/decrease in “speed” moving heat around IN the earth system but only Stephen’s diabatic loop can add/remove IR to/from space and affect system total energy e.g. global avg. surface temperature as shown by proper use of heat eqn. Like lapse rate explanations, Stephen’s words aren’t precise enough to “avoid delving down into the physics” (David term).

    The conjecture that makes physical sense for me agrees with Stephen’s words here:

    “ No doubt more GHGs have a similar effect but there is doubt as to whether their net sign is warming or cooling but either way it is infinitesimal compared to what sun and oceans do all the time.”

    The physics conjecture makes most sense is added but self limited IR active gas warming in lower troposphere, cooling in upper troposphere and stratosphere so both signs (spatial and temporal avgd. global). My main conjecture though as Stephen implies is science hasn’t yet found the physics&math to define or measure “infinitesimal” added IR active gas effect in either “sphere” but Stephen seems to imply “infinitesimal” is non-zero. Need more observations as Stephen writes to get closer to actual answer.

    Thus how close to zero is “infinitesimal” supports your local climate blog for sure.

  129. Stephen Wilde says:

    clivebest said:

    “However there is no logical reason why any new atmospheric equilibrium should not result in a slightly warmer surface temperature.”

    I think there is.

    The warmer the planet ‘s surface or atmosphere the more energy will be radiated out and so in the long term it can only remain at the temperature required for outgoing to match incoming.

    The rate of arrival of new energy MUST be matched by the rate of throughput for an atmosphere to be retained.

    That is why in my other article I said that energy in effectively gets a free pass straight through the system at equilibrium (the diabatic loop).

    All that is left is the energy circulating between surface and atmosphere (the adiabatic loop) and the speed of that loop MUST change in response to any forcing element otherwise ANY forcing element has the power to destabilise the system with a loss of the atmosphere.

    If GHGs or anything else make it ‘too warm’ then outgoing will exceed incoming until it cools back to the initial temperature.

    If they make it ‘too cool’ then incoming will exceed outgoing until it warms back to the initial temperature.

    The system can never remain either permanently too warm or too cool or the atmosphere will be lost.

    If there is no more energy from the external source the only way one can raise surface temperature is by the atmosphere radiating more energy back to the surface hence the reliance on DWIR but if that happens there will always be a residual component of the excess energy being obstructed by the atmosphere on each successive attempt at escape.

    Due to the interposition of the atmosphere between surface and space there will never be a point at which 100% of any excess surface energy can escape. There will always be a residual that will accumulate indefinitely. Equilibrium will never be regained.

    The idea that CO2 creates warming that then creates more humidity that then creates warming that then creates more humidity is just such an inpossible positive feedback loop but it would happen even without the involvement of water vapour.

    The ‘ideal’ rate of decline in temperature with height is set by gravity and the height of the atmosphere is set by incoming energy so if neither the decline in temperature with height nor the height of the atmosphere can change (rate of throughput fixed) the imbalance will be permanent and cumulative

    If however one can adjust the decline in temperature with height via real world lapse rates differing from the ideal lapse rate and adjust the height of the atmosphere (rate of throughput variable) then there need be no permanent warming of the surface and no rise in equilibrium temperature so that, long term, energy in can equal energy out.

    Fixed rate of throughput allows a rise in temperature but eventually leads to loss of atmosphere if ANY output throttling occurs and is not negated.

    The critical point is that the surface can never simply rise to a new equilibrium temperature when output throttling occurs because the excess energy at the surface cannot all get past the atmosphere to restore equilibrium however many attempts it makes. There will always be a residual at each attempt that gets cycled back through the atmosphere to the surface cumulatively.

    On the other hand a variable rate of throughput prevents a rise in temperature by negating any output throttling and retains the atmosphere.

    If GHGs slow down the rate of energy transmission in the diabatic loop (output throttling) then a speeding up of the adiabatic loop negates the effect (throughput throttling).

    No need for any rise in temperature although the distribution of energy within the system will change.

    All climate change is simply just such a redistribution.

  130. Max™ says:

    Wouldn’t the discussion over wet/dry lapse rates be better explained by looking at what the mechanism involved is which makes the difference?

    The wet lapse rates involve less cooling with increasing height, why?

    Well, water vapor which undergoes cooling would probably condense and release latent heat into the local atmosphere, right?

    So the drop off with height would be somewhere in between the fully saturated rate where any increase in height leads to water vapor condensing out and giving the smallest stable change in temperature with height, while the dry rate would be the largest stable change in temperature with height.

  131. clivebest says:

    Stephen,

    “The warmer the planet ‘s surface or atmosphere the more energy will be radiated out and so in the long term it can only remain at the temperature required for outgoing to match incoming.”

    That is correct.

    “All that is left is the energy circulating between surface and atmosphere (the adiabatic loop) and the speed of that loop MUST change in response to any forcing element otherwise ANY forcing element has the power to destabilise the system with a loss of the atmosphere.”

    I suspect you are right – but the speed of the loop can only regulated by the water cycle – not by convection alone.

    “If however one can adjust the decline in temperature with height via real world lapse rates differing from the ideal lapse rate and adjust the height of the atmosphere (rate of throughput variable) then there need be no permanent warming of the surface and no rise in equilibrium temperature so that, long term, energy in can equal energy out.

    Yes the environmental lapse rate will adjust to restore energy balance. So probably too will clouds and water vapour in the upper atmosphere.

    However I suspect there may also be moderate changes in surface temperature as seen in paleoclimate data. This is no real big deal. For example in one of your previous posts you suggested that the climate zones my extend in latitude. This would be beneficial to mankind – even though “average” global temperatures rise a litle.

  132. gbaikie says:

    So, the point of agreement is that a warmed atmosphere is the Greenhouse Effect.
    That a warmed atmosphere causes the surface air temperature to be warmer.
    And what not as much agreed is that warm air is kinetic energy. If this was agreed upon
    we could say that the increase in the kinetic energy of the atmosphere is a warmer
    atmosphere- that the greenhouse effect is about increasing in kinetic energy of the
    atmosphere.

    What is agreed upon is that the warmed air causes the skin surface of the planet to be
    warmer as compared to a planet without an atmosphere.

    But this is false. But if said the warmed atmosphere may prevent the skin surface from
    getting as cool at night as compared to a planet without an atmosphere this is
    plausible.
    A great difference between the Moon and Earth is that skin temperature is much cooler
    [in the day time] in the shade. In a shaded patio on Earth, the skin temperature will be around
    the air temperature, on the Moon the skin surface would 100 K [or more] cooler.
    Or a large rock casting shadow on the Moon will in about 2 hours of shade cause a 100 C
    skin surface temperature to become about 0 C and in several more hours the shaded area
    gets much cooler.
    “The data show an average decrease in surface temperature during the eclipse of around 100K, with some locations remaining warmer than others.”
    http://www.diviner.ucla.edu/blog/?p=610

    But this is a bit of distraction.
    Main agreement is a warmed atmosphere causes Earth
    to be warmer and the point to resolve is what warms and cools the atmosphere.

    So:
    “To summarise, Tim and I (and a few others) agreed that:

    GHGs are essential for inputting short wave (SW) radiant energy from the Sun.”

    So this referring to the 78 Wm-2
    “Atmosphere Flows

    Into atmosphere: 78+17+80+356 = 531Wm-2”

    And we know that our atmosphere takes big chunks out the sun spectrum as
    shown here:

    The above graph indicates H2O taking out most of the radiant energy before
    reaching the surface of Earth. O3 and CO2 are also taking some away. But
    the largest amount removed is not said to be from H20, CO2, O3, or any
    other greenhouse gas.
    Or the 78 Wm-2 is the amount agreed upon which absorbed by the atmosphere
    and such absorption seems to considered to converted into heat by the greenhouse
    gases or at least is involved in process we can call Thermalisation, wiki:
    “When a molecule absorbs energy, as in the technique of molecular fluorescence, the lifetime of the excited state is ~10^−12 sec. Then it rapidly loses energy to the lowest level of the lowest excited state; this is called thermalization.”

    An aspect of thermalisation is it’s occurring in a brief period of time. I would tend loosely call this
    re-radiated- and I am not sure if there technical difference between these terms, but word thermalisation suggests something is being heated.

    And for purpose of discussion we are suppose to consider it true, that direct sunlight
    warms gases. How it could do this is something I am fascinated to know, but for the sake
    of argument we are assume it’s true and assume the entire 78 Wm-2 of this direct solar energy
    adds to warming the atmosphere.

    And: “This mechanism would be independent of the level of GHGs in the atmosphere, assuming their concentration is already more than enough – which it is – to fulfill its two vital roles: (a) converting incoming SW radiant energy from the Sun to Kinetic Energy; and (b) converting Kinetic Energy back to LW radiant energy that is lost to space at the Top of the Atmosphere.I call this THROUGHPUT THROTTLING, a bit like the increasing restriction on the rate at which a fluid flows through a long narrow pipe as the pressure increases.”

    So the 78 Wm-2 amount being absorbed would not change [or change much] if one had more GHGs.
    Or if global CO2 doubled we should not expect bigger chunks taken out of the solar spectrum
    when reaches the surface.
    Which is somewhat reasonable and is convenient way of understanding Venus, where are massive chunks of solar radiation not reaching the surface of Venus, ie, more 99% of it not reaching the surface.
    And if the concern is what warms the atmosphere, and if direct sunlight warms the atmosphere
    that makes sense.
    And that I don’t believe that sunlight directly warms the atmosphere, should not get into the way
    of looking at these two alternative. After all both, sides agree the atmosphere is directly heat by sunlight, and we looking for agreement.

    If the surface converts 161 Wm-2 of sunlight into heat and the atmosphere converts 78 Wm-2,
    into heat one has to paid attention to the 78 Wm-2.
    Now it seems fairly obvious that if the atmosphere were absorb more than 78 Wm-2, the surface would have absorb less.
    So if the atmosphere absorbed 2 Wm-2 more sunlight the amount reaching the surface would 2 Wm-2 less. Now, David Socrates does not think an increase in GHGs could absorb as much as something like 2 Wm-2. But even if it did, it does not seem like it’s going help much in terms of warming the Earth much.
    But if the atmosphere were to absorb additional 2 Wm-2, the amount reflected light from the Earth surface would be diminish and one have a lower maximum skin temperature.
    One could say less sunlight reflected from the surface and a lower maximum skin temperature
    could seen as less wasteful [one is assuming atmosphere absorbs and converts sunlight into heat at what seems to be 100% efficiency- and the surface of earth does have such efficiency
    of converting sunlight into heat.
    But it seems if the surface absorbs less heat, then you should also have less surface to atmosphere radiation, which currently is suppose to be 356 Wm-2.

    So I would agree that an increase in GHGs should not significantly [more than error in amount being currently measured] increase from the current 78 Wm-2, which said to be absorbed by the atmosphere, but even it were to increase, it’s not clear this should increase global temperatures.

  133. Stephen Wilde says:

    clive.

    In paleoclimate data the time scales are such that Milankovitch cycles and atmospheric mass could cause variations and the effect of such variations would indeed be mitigated by shifts in the climate zones.

    The water cycle makes it very much easier for stability to be maintained as compared to planets without water but convection would be enough on its own on such planets otherwise the atmospheres would be lost. Huge planet wide dust storms on Mars and the power of Venusian winds come to mind. Our water cycle just means that any necessary adjustments need not be so violent. Perhaps the reduction in violence assisted the development of life.

    gbaike.

    I don’t think it is a matter of skin temperature alone. An atmosphere evens out both day and night extremes by redistributing energy around the whole sphere and in doing so achieves a higher global average temperature than the mid point between day and night temperatures on a planet without an atmosphere.

    On Earth much of the warming of the atmosphere was initially achieved aeons ago when energy conducted to non GHGs from the surface and created the very first atmosphere. Non GHGs do not get directly warmed by sunlight coming in.

    Ever since then that initial block of energy has been recycled up and down adiabatically and will always be so as long as there is an atmosphere. Obviously the photons themselves change over time but the amount of energy involved is fixed by mass held by gravity and irradiated.

    The amount of energy being so recycled between surface and atmosphere is the source of the additional warmth that is the subject of concern.

    It is indeed about kinetic energy but stability is maintained because the adiabatic loop is variable in speed and size and so can influence atmospheric volume whereby KE can be shuffled to and fro to PE and back to keep the temperature of the entire system just right to keep top of atmosphere balance steady over time as long as there are no changes in mass gravity or insolation.

    I can see no other way that it could be done.

  134. gbaikie says:

    More about 78 Wm-2 and converting sunlight into heat.

    Not sure how the 78 Wm-2 is arrived at, but if sunlight goes thru more
    atmosphere it loses more watts per square meter. And fact that sunlight
    loses more energy the more atmosphere goes thru could be unrelated
    to this number of 78 Wm-2.
    But the sunlight is already going thru lessor and larger amounts of GHGs-
    depending on time of day and latitude [angle of sun]. In other words
    one could measure whether or not increase of GHGs would increase
    the 78 Wm-2 amount. One does not need to increase global GHGs,
    at lower angle of sunlight, the sunlight is traveling thru more GHGs.

    A kilowatt hour is equal to 1000 times 3600 seconds or 3.6 million
    joules.
    78 Wm-2 suggests that per 24 hour period, the amount joules added
    is 78 times 3600 times 24 which is 6.7 million joules.
    A meter square column of air from surface to space is about 10 tons
    of air.
    Now long long does it retain this heat.
    If add 6.7 million joules to 10 tons of water or 10 tons of air, how does it
    take to lose, say 1/2 of this energy to Space.

    Let’s say you added 6.7 million joules to 10 tons of water at bottom of ocean
    and compared this to 10 tons of water at the surface of ocean.
    It seems the energy would get to space quicker if at the surface.

    First to heat 1 kg of water by 1 K requires about 4200 joules.
    http://www.engineeringtoolbox.com/water-thermal-properties-d_162.html

    So ton of water is 4.2 million joules per k increase and 10 tons
    is 42 million, so we talking increase of about .159 C.
    So you have some sea water which 3 C and you add 10 tonnes
    of seawater which is 3.159 C. The warmed water rises and a bit and
    mixes and conducts it’s heat to the rest of the water. And the answer
    is probably more than 1000 years.
    On the surface of ocean, say water is 25 C per degree it’s 41.8
    million joules so .16 C. And warmer water does rise but spreads out-
    but it mixes and conducts heat to surrounding water. And so the amount
    heat involved getting into space is the warmer water would spread out over
    large area and if temperature over large area was about 1/10 C warmer,
    so probably less than a year.
    Or a few joules more heat lost per square meter of surface
    per second, and some of heat would cause more water to evaporate. Etc.

    Now how much does 6.7 million joules heat up 10 tons of air?
    “For ordinary calculations – a value of cp = 1.0 kJ/kg.K”
    http://www.engineeringtoolbox.com/air-specific-heat-capacity-d_705.html
    So 10 million joules per 10 tons per K. So an increase of .67 C.

    [It doesn’t seem like if you had a balloon with 10 tons of air in it and warmed
    the air by .67 C, that you would not get any significant amount of buoyancy. And
    this is true if at the surface or the stratosphere. Or a safe guess is if balloon
    mass weighed a ton, it would not rise.
    Or if buoyancy was measured in less 1mm per second
    per second one might have some buoyancy. But I think other convection
    mechanisms could be more significant.]

    So if such a release of warmed air was released at surface or stratosphere how long
    would it take for that heat to reach space?
    I am not sure. But it seems the air at surface would warm a surface and that
    surface would radiate the heat into space. That is my take.

    But instead air, say it was CO2, so 10 tons of CO2 somewhere around .6 C
    warmer then surrounding air.
    With CO2 [according to a theory] it seems more energy would be lost if in the
    stratosphere, but how many joules per second? Would such warmed CO2 lose?
    How long would take to radiate 6.7 million joules?
    You may claim the atmosphere radiates 199 W/m-2, but I mean if atmosphere
    is warmed slightly [.6 C]. Would it be more than 10 W/m-2
    added to the 199 W/m-2 ?
    There are 86400 seconds in a day, so to get 6.7 million joules to space in a day
    requires 77.5 W/m-2 does that seem correct?

  135. Trick says:

    Stephen 10:27pm: “…because the adiabatic loop is variable in speed and size and so can influence atmospheric volume whereby KE can be shuffled to and fro to PE and back to keep the temperature of the entire system just right.”

    Size? Meaning what exactly? David is right; need precision not just words to soundly investigate the “infinitesimal” & gain support. Top post is more precise.

    Temperature isn’t conserved Stephen; esp. not “just right” as observations show near surface global avg. temperature heat flow throttling varies monthly even though mass, insolation and gravity are constant. These observations prove there are other drivers of near surface global temperature or T would be measured constant & it is not.

    Energy IS conserved so the variable speed adiabatic loop can’t exchange KE with surroundings; if it does then you need a more precise term than adiabatic loop. The diabatic loop varies the surface temperature with SW insolation, LW surface emission, albedo and as in top post variations of “the lowest part of the atmosphere radiates (LW) energy at an enhanced rate (333Wm-2) towards the surface” as shown in the thermometer records and shown, as Clive mentions, in paleo records.

    Meaning for heat flow throttling in Stephen’s words:

    “ No doubt more GHGs have a similar effect but there is doubt as to whether their net sign is warming or cooling but either way it is infinitesimal compared to what sun and oceans do all the time.”

    Which I would more precisely restate understanding that heat flow throttling is not keeping the near surface global avg. temperature exactly right or even constant:

    “ No doubt more IR active gases, ENSO et. al. circulations have a similar effect but there is doubt as to whether their net sign is warming or cooling but either way it is small enough to make measurement difficult compared to what sun, clouds, atm., land & oceans do all the time.”

    Stephen 5:29pm:

    “The warmer the planet ‘s surface or atmosphere the more energy will be radiated out and so in the long term it can only remain at the temperature required for outgoing to match incoming.”

    Yes, precisely. Global T varies in this manner. More IR active gas doesn’t change the atm. energy content, added IR active gas slows the cooling of the near surface troposphere and exactly opposite increases cooling the upper troposphere and stratosphere. Energy is conserved, temperature is not conserved; T varies in this way even with constant mass, insolation and gravity so the atm. is retained for 4bln years give or take.

  136. gbaikie says:

    “gbaike.

    I don’t think it is a matter of skin temperature alone. An atmosphere evens out both day and night extremes by redistributing energy around the whole sphere and in doing so achieves a higher global average temperature than the mid point between day and night temperatures on a planet without an atmosphere.”

    I also don’t think it’s about skin temperature. But skin temperature the warmest element involved. And if take away atmosphere to compare worlds with and without atmosphere, there is no air on world you given no air to:) And the obvious common element between the world is the skin surface temperatures. And an airless world would have a warmer skin temperature.

    “achieves a higher global average temperature than the mid point between day and night temperatures on a planet without an atmosphere.”

    Certainly true of the Moon and of Mercury but both have extremely long nights. If Earth had 28 day long day- 14 day night and day, it would be quite a bit colder at mid point between day and night.

    “On Earth much of the warming of the atmosphere was initially achieved aeons ago when energy conducted to non GHGs from the surface and created the very first atmosphere. Non GHGs do not get directly warmed by sunlight coming in.”

    Very first atmosphere?
    Well, if you think the proto-Earth met a proto-Moon, that event would made prior Earth’s very first atmosphere somewhat irrelevant. After such an impact, we could say Earth first atmosphere would have included iron gas. And the end of planet vaporizing impactors and the early beginning of the start of life on Earth- put nail in coffin of idea that life had billions of years to evolve.

    But by time life showed up- somewhere around 3.8 billion years- the atmosphere
    would have been much cooler.

    If believe in some other way that we got a moon, Earth would still have been formed by huge impactors [including objects a large as dwarf planets, such as Ceres] which have also started with Earth being scorching molten ball [with perhaps iron gas being a part of the atmosphere- but if not hot enough for iron gas, then at least such a hot atmosphere that it makes Venus seem
    somewhat cool.]

    “It is indeed about kinetic energy but stability is maintained because the adiabatic loop is variable in speed and size and so can influence atmospheric volume whereby KE can be shuffled to and fro to PE and back to keep the temperature of the entire system just right to keep top of atmosphere balance steady over time as long as there are no changes in mass gravity or insolation.

    I can see no other way that it could be done.”

    Generally I suppose agree. But you talking about an atmosphere. Which is essentially weather.
    Whereas oceans are essentially climate

  137. Max™ says:

    Earliest life was possible around 2 billion years ago if not earlier.

    Venus has a very long night and no diurnal variation, the lower the mass of the atmosphere, the greater the diurnal variability will be.

  138. Stephen Wilde says:

    In so far as gbaike and Trick still appear not to fully agree I think that arises from semantics and not taking full account of all my words within their relevant contexts so I feel no need to respond in detail.

    We seem to all be in broad agreement and just circling around points of detail.

  139. gbaikie says:

    “Venus has a very long night and no diurnal variation, the lower the mass of the atmosphere, the greater the diurnal variability will be.”

    If Venus had 50 atmospheres instead of 92, would there be much difference in diurnal variation?
    What if instead it was 20 atms? Where is the point where it makes much difference?
    Does how hot the atmosphere is make a difference? If Venus was at Earth distance would it be radically different- would be much cooler and would it have more diurnal variation.

    The reason I think Venus is hot, is because the clouds are being heated by sunlight.
    So accordingly I think Venus could lose 1/2 it’s atmosphere and not have much change.
    Though if were to add a Pacific Ocean worth of water- it changes the concentrated sulfuric clouds and therefore has radical difference.
    And if had Venus at Earth distance, the same clouds would not be as much warmed up as much- and therefore radically change Venus temperature.

    It seems to me it’s simpler, that if put Venus at Mars distance, the CO2 would liquify and freeze, and it might even be colder than present Mars.

    It’s interesting question is what are “common planets” like?
    Everyone seems to think Earth is not a common planet. Maybe that is true, but
    what is a common planet? Is Venus typical, or is it as odd as Earth?

    We are finding thousands of planets around different stars. But we need bigger telescopes- really big telescopes in the space environment.
    I think spend trillions dollars on space telescopes is much wiser than spending tens of trillions
    increasing the cost of energy. The amount of public money spend on wind mills would given us several fairly large telescope [not as big as I would want, but big enough- far bigger than we probably will have for next few decades. But perhaps if and when the James Webb Space Telescope is up and operating [5-10 years], it will whet an appetite for something bigger.]

  140. Trick says, February 25, 2013 at 12:53 am: Stephen 10:27pm: “…because the adiabatic loop is variable in speed and size and so can influence atmospheric volume whereby KE can be shuffled to and fro to PE and back to keep the temperature of the entire system just right.” Size? Meaning what exactly? David is right; need precision not just words to soundly investigate the “infinitesimal” & gain support. Top post is more precise.

    Trick, Thanks for the observation. So between the three of us (and any others who can be dragged back from off-topic musings about Venus) can we perhaps look at Stephen’s ‘adiabatic loop’ concept in more quantitative detail? I certainly haven’t lost hope that we can pin things down with some maths.

    As I understand it, Stephen’s ‘adiabatic loop’ is that fraction of the energy that is carried by convection up the atmospheric column, being converted from KE to PE as it goes; and then, on the way down, is converted back from PE to KE.

    The ‘diabatic loop’ refers to that fraction of the energy that is carried by convection up the atmospheric column and then is radiated to space by the GHGs at the ToA.

    In both cases, the physical transport mechanism is the same: the frictionless ‘loop’ engine, involving the endless circulation of air, upwards from base to top and then back down from top to base.

    So using the values in my ultra-simple 1-dimensional model of the Atmospheric Column (Fig.7), let’s talk quantities:

    199W is the power flowing up the column to space
    1m2 is the cross-sectional area of the column
    59K is the temperature difference between surface and ToA
    10,000m is the distance between surface and ToA

    We postulate that the atmosphere somehow offers resistance to the flow of energy, thus setting up the temperature difference. The effective conductivity of the atmosphere, katm is easily calculated by re-arranging the heat flux formula provided for Thought Experiment 2 (Fig.4):

    katm = 199*10,000/(1*59) = 33,729Wm-1K-1

    Wow! That’s enormous. But this, of course is the effective thermal conductivity of the Atmospheric Column, not the real thermal conductivity of air (a mere 0.024Wm-1K-1). The huge number really represents the frictionless mechanical properties of convection.

    Or does it? Tim Folkerts might say that, although the arithmetic is correct, it is caused mainly (or entirely) by the radiative gases at the top and not much (or not at all) by the convective flow on the way up.

    Impasse !

    So now I think we have to ask Tim F: Can you justify mathematically an ‘effective conductivity’ that is equal to (or at least a major part of) 33,729Wm-1K-1 and which is caused not by convection but by restrictions on the ability of GHGs at the ToA to radiate to space?

    And perhaps at the same time we could also ask Konrad to justify his assertion with quantitative proof that “the ERL thing won’t work”.

    Er…where the heck are you, Konrad? 🙂

    DC

  141. Stephen Wilde says:

    David.

    The diabatic loop would also include radiation directly from surface to space and conduction from surface to space, not just convection.

    We need to give a free pass straight through for the top of atmosphere solar incoming.

  142. Trick says:

    David 3:36pm: “So using the values in my ultra-simple 1-dimensional model of the Atmospheric Column (Fig.7), let’s talk quantities.”

    Good but howl of anguish here, I would use Fig. 5 since Fig. 7 simplification obscures some flows.
    Numerically Stephen’s adiabatic loop shown in Fig. 5 consists of left to right across bottom:
    80+17 = 97

    If truly adiabatic then does not affect surface temperature as no energy goes in/out to surroundings no matter the adiabatic loop speed or size.

    Stephen’s diabatic loop simplest, basic physical model Trenberthian consistent:

    239 SW net in – (396-157) LW net out = 0 LTE in balance.

    157 LW comes from atm. all by itself radiating at surface = 157 = 333-80-17-78-1 (missing or absorbed in L&O). The atm. all by itself also radiates to space a lesser amount due to whatever flavor lapse rate you like along with surface 40 to space.

    So as atm. opacity increases, the 157 goes up and forces 396 up to stay in balance which forces a surface temperature increase.

    Meaning as atm. opacity (AKA “heat flow throttling”) goes up, near surface global avg. temperature forced up which also might affect the surface window of 40 in Fig. 5. Note all this conserves energy, not temperature.

    Are you with me?

  143. Trick says:

    Stephen 3:56pm:”.. conduction from surface to space.”

    More precisely atm. gas conduction up to TOA & not to space obviously.

    “The diabatic loop would also include radiation directly from surface to space…”

    Ok, add it in the diabatic loop numerics explicity:

    239 SW net in – (356+40-157) LW net out = 0 LTE in balance.

  144. Max™ says:

    So now I think we have to ask Tim F: Can you justify mathematically an ‘effective conductivity’ that is equal to (or at least a major part of) 33,729Wm-1K-1 and which is caused not by convection but by restrictions on the ability of GHGs at the ToA to radiate to space? ” ~David

    Hmmm, doesn’t Venus supply a proof by contradiction here?

    We only have 160~ leaving the top of the atmosphere there total, about 60,000 meters between “top” and “bottom, and a difference of over 500 K between them.

  145. Kristian says:

    Trick, you say: “So as atm. opacity increases, the 157 goes up and forces 396 up to stay in balance which forces a surface temperature increase.”

    The 396 W/m^2 upward surface IR flux is a result (a function) of the specific temperature and emissivity of the surface. Nothing else. If more IR is coming down from the atmosphere, this would mean the net IR flux leaving the surface (its radiative heat loss) would be reduced. This WOULD then initiate a buildup of heat –> warming. But since our Earth system is a highly dynamic, not a static one (you know, the whole ‘all else being equal’ business), the convectional heat loss mechanism (conduction/evaporation) would respond more or less as soon as this warming started taking place, and we would be back to square one. In the end, more IR down from the atmosphere (caused for instance by increased optical depth) would only lead to the surface shedding relatively more of its heat via convection and relatively less through IR radiation. The surface temperature would remain the same. (There will of course always be a lag, but considering the minutely gradual increase of GHGs in the atmosphere, this lag would hardly be of consequence and the (hypothetically) incremental warming steps would hardly be measurable before the temperature fell back to its original level. The only way I could imagine actually being able to observe an effect from this mechanism, is through transient cloud forcing.)

  146. Stephen Wilde says, February 25, 2013 at 3:56 pm: David. The diabatic loop would also include radiation directly from surface to space and conduction from surface to space, not just convection. We need to give a free pass straight through for the top of atmosphere solar incoming.

    Stephen,

    1. Oops! Perhaps, I should have added the 40Wm-2 radiation through the Atmopspheric Window as part of the diabatic contribution. Although it is hardly conveyed up to ToA by a ‘loop’ is it?!

    2. Conduction from surface? There is conduction/convection at the surface (17Wm-2). Conduction alone won’t get you anywhere!

    3. Free pass for solar incoming? Solar incoming that is absorbed by the surface, yes. But the 78Wm-2 absorbed by atmosphere? No. But the latter is included in my ultra-simplified Fig. 7 as if from surface.

    DC

  147. Stephen Wilde says:

    Point taken about conduction but it does remove energy from the surface and return energy to the surface and so is part of both loops.

    As regards radiation from surface to space that is part of the diabatic loop.

    The energy content of the adiabatic loop is limited by the adiabatic heating on the downward leg.

    The diabatic loop can still be termed a loop despite radiation from surface to TOA being a component. Energy comes in and goes out in a loop between sun and surface whatever the mechanism.

    If energy out equals energy in then that is a free pass straight through. Just rework the numbers accordingly.

    Beware of making this overcomplicated. You don’t need to break it down to separate energy transfer mechanisms.

    The simple fact is that energy in equals energy out over time so they net out (diabatic).

    The remaining energy goes from surface to air and back again so that nets out too (adiabatic).

    It is only the latter that represents warmth retained within an atmosphere.

    In fact it doesn’t even matter if one calls it DWIR or adiabatic compression. Either way the system response is equal and opposite as long as mass, gravity and insolation stay the same.

    If anything speeds up or slows down the diabatic loop then there is an equal and opposite response in the adiabatic loop,

    The background mechanism involves reducing pressure with height which in turn reduces temperature with height and the relative proportions of KE and PE at any given height when overall expansion or contraction occur.

    It is simple, elegant and, I think, true.

    After suitable time lags total system energy content and thus surface temperature fails to change unless mass, gravity or insolation change.

    Of course in reality the system is never in equilibrium so it oscillates around the mean constantly.

  148. Trick says:

    Kristian 5:23pm – “If more IR is coming down from the atmosphere…”

    David is commendably trying to push discussion to energy flow numerics, which helps I think. So if more IR (say 2 W/m^2) does come down from increased “heat flow throttling” i.e.increased opacity atm. all alone in same steady state conservation of energy (mass, insolation, gravity remain constant) then Stephen’s adiabatic loop 80+17= 97 might go up those 2:

    81+18=99

    With energy conserved, Stephen’s diabatic loop would then go to:

    239 SW net in – (357+41-159) LW net out = 0 LTE in balance.

    159 = 337 – 81 – 18 – 78 – (1 missing heat)

    The 333 goes up to 337 for balance by 2 from increased adiabatic loop and 2 from increased opacity atm. all by itself.

    So Stephen would be right, the adiabatic loop speeds up with more size but since energy is conserved, the adiabatic loop can’t compensate for the necessary increased near surface global avg. temperature due the increase of 2 + 157 = 159 forcing up the 396 to 398=357+41 to balance.

    The numerics of Fig. 5 allow a lot more precise physical discussion IMO.

    ******

    Alternatively, if Stephen’s adiabatic loop does not speed up much if at all (my view):

    Adiabatic loop stays roughly the same:

    80+17 = 97

    Diabatic increases avg. surface temp. by the 2 say split evenly between window and atm.:

    239 SW net in – (357+41-159) LW net out = 0 LTE in balance.

    159 = 335 – 80 – 17 – 78 – (1 missing heat)

    The 333 only then need go to 335 for balance by 2 from atm. all by itself. Of course, the adiabatic processes may change a bit more and the 333 go up a bit more than 335, depending on what flavor of lapse, albedo, emission or balance you like.

  149. Trick says:

    Stephen 6:48pm: I mostly agree except our 1 big difference where you conclude:

    “If anything speeds up or slows down the diabatic loop then there is an equal and opposite response in the adiabatic loop.”

    The conservation of energy numerics of Fig. 5 (see above example 7:20pm) show the adiabatic loop cannot speed up to compensate, as I have been saying all along that speed up would take more energy created from nothing to accomplish. The numbers show this conclusively. See if you can follow that post or find any issues with my numeric example.

    Also, sure the conduction is thrown into the 356 and/or the 17. Can reduce the 356 and/or 17 for explicit conduction by any number you wish, just be sure to add it back appropriately for energy conservation.

  150. Kristian says:

    “In the end, more IR down from the atmosphere (caused for instance by increased optical depth) would only lead to the surface shedding relatively more of its heat via convection and relatively less through IR radiation. The surface temperature would remain the same.”

    This leads to the following conclusion: It is not enough for the atmosphere to restrict the radiative heat loss (net IR flux) from the surface in order to induce warming. This would only work if radiation was the only means by which the surface could lose energy. In a convective setting like ours, this is of course not the case. The surface would always be directly and intimately connected with the atmosphere above it (temperature/cooling rate) through convection. Convection (on Earth, basically, latent heat transfer – evaporation) would far and away be the main regulator of the surface energy balance. Not thermal radiation.

    This means that, for the atmosphere to be able to cause warming (accumulation of excess energy) at the surface, it needs to restrict the TOTAL heat loss; both the radiative AND the convective. How to restrict convective heat loss from the surface? Lower the temperature gradient. Reduce the temperature difference between the warmer surface and the cooler air layer above it. This mechanism relates directly to the mentioned ERL (Effective Radiating Level) issue.

    The only problem with this hypothesized mechanism is that it is not observed to work. Observations from the real world clearly indicate the opposite course being taken by Nature. The temperature gradient from the surface up has increased during the modern warming era, the temperature difference between the surface and the air layer above has gradually become greater and greater. This corresponds well with intensified convection as a response to direct (solar) surface warming, which also shows up as increased OLR at TOA (a function of surface temperatures, tropospheric temperature and humidity, and clouds –> ENSO with aftereffects) since the early 80s.

  151. Stephen Wilde says:

    Trick.

    Why would there need to be more energy created from nothing ?

    More energy from a slowdown of the diabatic loop results in a faster adiabatic loop

    All that is necessary is for volume to change along with the angle of the lapse rate slope. It all happens within the atmosphere and not at the surface.

    Radiative theory is fixated on surface temperature for obvious reasons but the presence of an atmosphere removes the action from the surface to levels higher up.

    From a simple observation of real world behaviour the effects of each loop must be equal and opposite.

    If the effects were not to be equal and opposite then imbalances at top of atmosphere could not be corrected for and global temperatures would be vastly more unstable and most likely the atmosphere would have been lost.

    I don’t think your numbers match the reality. I think your numbers assume a surface temperature increase by not allowing a change in the lapse rate slope along with volume. Such a variation in lapse rate slope can occur at any level vertically or any location horizontally around the globe.

    You don’t take a point in the stratosphere with its reversed lapse rate slope and extrapolate that to the surface so you cannot do it elsewhere either.

    You have to work with the real world lapse rates throughout the atmospheric column and in three dimensions all around the globe due to the variations in heights and slopes caused by the circulation pattern.

    It is only the net average slope globally that can be used as a base for extrapolation downward and that is not represented by any currently known number.

    Even if the net average number were known it would not apply exactly or not for long in any given location.

    Your figures are therefore wholly unworldly.

    Look how stable the system is with little or no correlation with CO2 even at 7000ppm.

  152. gbaikie says:

    “As I understand it, Stephen’s ‘adiabatic loop’ is that fraction of the energy that is carried by convection up the atmospheric column, being converted from KE to PE as it goes; and then, on the way down, is converted back from PE to KE.

    The ‘diabatic loop’ refers to that fraction of the energy that is carried by convection up the atmospheric column and then is radiated to space by the GHGs at the ToA.

    In both cases, the physical transport mechanism is the same: the frictionless ‘loop’ engine, involving the endless circulation of air, upwards from base to top and then back down from top to base.

    So using the values in my ultra-simple 1-dimensional model of the Atmospheric Column (Fig.7), let’s talk quantities:

    199W is the power flowing up the column to space
    1m2 is the cross-sectional area of the column
    59K is the temperature difference between surface and ToA
    10,000m is the distance between surface and ToA”

    It seems to me in terms of a diabatic loop, a clear example thunderstorm clouds:
    Cumulonimbus cloud
    “Well-developed cumulonimbus clouds are characterized by a flat, anvil-like top (anvil dome), caused by wind shear or inversion near the tropopause. The shelf of the anvil may precede the main cloud’s vertical component for many miles, and be accompanied by lightning. Occasionally, rising air parcels surpass the equilibrium level (due to momentum) and form an overshooting top culminating at the maximum parcel level. when vertically developed, this largest of all clouds usually extends through all three cloud regions. Even the smallest cumulonimbus clouds dwarfs its neighbours in comparison.”
    http://en.wikipedia.org/wiki/Cumulonimbus_cloud

    Though these clouds are largely about water vapor and condensation.
    So one has air parcels which are buoyant.
    It seems to me one can have air parcels which are buoyant which
    are not movement of gas- they are movements of heat but with
    enough heat one gets movement of air. And if one get enough
    heat so air moving upward you get an accelerated movement.
    Or individual gas molecules aren’t accelerated. Acceleration
    is about one direction, and it’s only a large group of molecules
    which can described as moving in one direction.
    And with accelerating air masses you get “overshooting top culminating at
    the maximum parcel level”. And if air is moving, the air can carry stuff
    suspended in it [such as water droplets].

    But it seems the adiabatic loop isn’t solely comprised of movement
    of air [it could even exclude movement of air], but is about movements
    of heat.
    So gases diffuse heat, but gases also have direction the heat
    moves and this direction is caused by there being gravity.
    An analogy is with water one has waves that are movement of energy-
    water isn’t carried across the ocean- the energy of the wave
    travels across the ocean.

    So waves in water is mechanical energy, movement of air parcels
    is heat energy.

    So that one leg of the hoop, going up. And we have the other leg
    going down. How is this described. It has to occur- if something is going
    up, something else has to go down. Would call this a vacuum or low pressure
    weather system. Or what?
    One could say heat is one direction. A ocean wave has one direction,
    though one has undertow when it hits the shore.
    [And waves also apparently doing a lot of mixing the ocean.]

    If one is moving air it very obvious about a need to have the downward leg.
    And if you believe air being cooled in upper atmosphere, then it’s simply
    that the cooler air falls. And it seems if had much of this cooling,
    we have a lot of this cold air falling.
    So I suppose for those believing majority of heat leaves earth at TOA,
    the down leg is self evident.
    But it seems to me there would be too much cold air falling, and perhaps
    they should be the ones to explain and quantify it.

  153. Stephen Wilde says:

    Trick said:

    “The 333 goes up to 337 for balance by 2 from increased adiabatic loop and 2 from increased opacity atm.”

    Surely the 333 goes to 335 from increased opacity then comes back down to 333 from increased adiabatic loop ?

  154. Trick says:

    Stephen 8:30pm: “Your figures are therefore wholly unworldly.”

    These numerics are just an example. What exactly is unworldly with my example? David’s numerics are a good way to dig in to what you consider unworldly.

    “Look how stable the system is…”

    Sure shows adiabatic processes don’t compensate over eons, right? We already know not even monthly.

    And stably means we exist to blog! No question +/- 15C is way more unstable than last century+. And there is way more than CO2 as a driver over eons, some say CO2 is a lag – as you point out even uncertain of sign. Now atm. mass, ocean circ., other atm. composition & insolation are drivers which influence the 239, the 356, the 80, the 17, the 333, probably the 40 in ways we don’t have a handle. But still MUST have energy conservation along the way or dq = m*Cp*DT/dt during transient times.

    IIRC this graph shows about two trips around the galaxy bobbing up and down thru the plane. Could have external extra-solar changes too.

    Stephen 8:39pm: The 333 goes to 335 only if adiabatic loop doesn’t speed up. Goes to 337 if adiabatic loop speeds up 2 also. See how they are interconnected. Numerics are very informative, much more precise.

    The 335 can’t come back to 333 unless the example extra 2 W/m^2 opacity is removed from atm. The adiabatic processes can’t “clean” it out. Note for homework, work thru -2W/m^2 as starting example (ocean, mega fauna or vegetation sequester IR active gas).

    ******

    Kristian 8:24pm: “How to restrict convective heat loss from the surface?”

    Where does surface lose convective heat to? Only to the atm. for which I’ve accounted properly (at least as proper as believe Trenberth which is sort of assumed more or less in top post). No convective heat loss to space only radiative. Thermals and LH stay in the adiabatic loop; Stephen can use “adiabatic” b/c no heat loss to space from these 2 atm. processes.

    You could explain much more clear with numerics consistent with conservation of energy, as could Stephen.

  155. Stephen Wilde says:

    “It seems to me in terms of a diabatic loop, a clear example thunderstorm clouds:”

    The initial updraft is caused by diabatic heating of the surface.

    Once a parcel of air leaves the surface then it is part of the adiabatic loop and cools accordingly.

    At some point it condenses out the water vapour which radiates energy to space and that radiated energy is part of the diabatic loop.

    The drier air then descends and warms adiabatically until it gets back to the surface.

    It is like an elevator taking passengers up in the form of water vapour and letting them get off at various levels where condensation occurs.

    Then it goes down empty and picks up another load.

    The faster and so more frequent the trips up and down or the larger the rising parcels / elevator cabins the more energy they can carry in a given period of time.

    Non condensing GHGs if they have a net warming effect (debateable) do so within the atmospheric column and not at the surface so they affect the air and not the surface. The air around them then holds more KE which increases local atmospheric volume and distorts the lapse rate locally to compensate.

    None of that directly affects the surface which is insulated from a temperature change by the distorted lapse rate slope.

    One simply must not extrapolate the lapse rate backwards from a point in the atmosphere to ascertain surface temperature because the real lapse rate at any given place or time has been distorted by events going on in the atmosphere and off the surface.

  156. Stephen Wilde says:

    “Sure shows adiabatic processes don’t compensate over eons”

    Didn’t you see the long flat spells capping the temperature with the only significant changes being Milankovitch cycles induced by changing energy coming in at TOA ?

    What do you think does that ?

    “The 335 can’t come back to 333 unless the example extra 2 W/m^2 opacity is removed from atm. The adiabatic processes can’t “clean” it out.”

    Why not ?

    If the effect of the extra opacity (if not due to more mass) is not removed then radiation in will permanently be higher than outgoing radiation.

    At every successive attempt at radiating out the excess energy a residual fraction will be obstructed by the atmosphere and accumulate within the system. Equilibrium will never be regained.

    Of the rise from 333 to 335 a little less than the extra 2 will be radiated out. Then a fraction of that fraction will fail to be radiated out and so on ad infinitum. Small increments but 4 billion years to play with. And on a water planet humidity is supposed to keep increasing which accelerates the process.

    It didn’t happen at 7000ppm. Temperatures maxed out at 25C regardless. And they maxed out at that level when CO2 was far lower too.

  157. Kristian says:

    Trick: “The 333 goes up to 337 for balance by 2 from increased adiabatic loop and 2 from increased opacity atm. all by itself.”

    You seem to be double counting energy here.

    I think in this case it’s prudent to keep to the NET fluxes. Here is how I see it:

    More IR is coming down from the atmosphere, let’s agree on your 2 W/m^2. That’s 335 W/m^2 of ’enhanced’ DLR flux. This reduces the net IR flux (radiative heat transfer) from the surface to the atmosphere (356-335 = 21 W/m^2, 40 W/m^2 still go straight through). This is where energy would be able to start accumulating at the surface. But notice that at the same time it would also, in this initial state, reduce the net energy flux transferred via thermal radiation from the surface to the atmosphere (radiative heat gain from below) – before, +23 W/m^2, after, +21 W/m^2.

    Then, as soon as warming starts taking place, convection steps into action, and after having balanced out the radiative perturbation, the sensible+latent heat transfer from surface to atmosphere has increased from 97 to 99 W/m^2. That is, more heat is now transferred from the surface to the atmosphere by way of convection while less heat is transferred by way of radiation.

    But most importantly, in the real world, remember that the rise in DLR from increased atmospheric opacity will never globally come in packages of 2 W/m^2. Not even remotely close. Theoretically, the radiative forcing from increasing atmospheric CO2 alone has strengthened by somewhere between 0,7 and 0,9 W/m^2 over the past 40+ years. This surely doesn’t happen overnight.

  158. Trick says:

    Stephen 8:30pm: “I think your numbers assume a surface temperature increase by not allowing a change in the lapse rate slope along with volume.”

    I’ve not used anything to do with allowing or not allowing lapse rate slope change, used nothing about volume. Those two are whatever they need to be, this is why these are red herrings:

    The slope of the lapse rate won’t change with reasonable surface temperature change b/c as you point out g and Cp are ~constant as is mass, so g/Cp ~same and Poisson lapse slope also stays the same rate as Po, R/Cp are ~same even with +2W/m^2 “down from atm.”

    What changes with the +2W/m^2 is the starting point of the lapse curve To at Po. This shows Stephen’s diabatic loop establishes the surface To but not the lapse slope which theory shows rate is controlled to within 10% or 20% of observed lapse rate by Po, R/Cp and g up thru tropopause ~11.1km or 223.46mb. Above that, the atm. gas is heated from above so convection ceases w/no lapse or T ~constant (=216.65K U.S. standard) until ~20.1km up or 54.4mb where T starts to increase.

    This is extremely important point to really “get”, I observe some posters miss this key text book point.

    On volume, you can pick any volume you want as I’ve said before, the atm. goes up to the last N2 molecule in orbit, the exact volume is pretty much undefined but not the density. That’s why atm. science uses P=density*R*T for atmospheres.

  159. Kristian says:

    Trick: “Where does surface lose convective heat to? Only to the atm. for which I’ve accounted properly (at least as proper as believe Trenberth which is sort of assumed more or less in top post). No convective heat loss to space only radiative. Thermals and LH stay in the adiabatic loop; Stephen can use “adiabatic” b/c no heat loss to space from these 2 atm. processes.”

    You apparently missed the part where the diabatic loop ALSO involves convection. Do you really believe that energy being lifted from the surface to the tropopause by way of convection can not and will not be radiated off to space? What a peculiar position …

    http://chiefio.wordpress.com/2012/12/12/tropopause-rules/stratosphere-radiation-by-species-1460/

  160. Trick says:

    Kristian 9:35pm: “..remember that the rise in DLR from increased atmospheric opacity will never globally come in packages of 2 W/m^2.”

    LOL, of course, pick anything you want besides 2W/m^2 I used for illustration – it was convenient (and more lucid I hope) to add 1 to 80 and 1 to 17 for grins then compute what happens to diabatic loop from energy conservation w/round numbers. As is hammered out in Part 1 and 2, Trenberthian figures are not exact (esp. not to 3 digits) but a decent ground rule for discussion.

    I was nervous of double counting 2 to get 4, or 333 to 337 but it turns out not to be double counting, that is what the numerics show must happen for energy to be conserved assuming +2W/m^2 “..more IR is coming down from the atmosphere..” averaged over the spectrum allowing a proper increase of speed and size in the adiabatic loop.

    That is why in my view, the adiabatic loop doesn’t change as much as Stephen writes so I showed with no adiabatic loop increase also (below the stars). Makes it very evident to me that the adiabatic loop cannot compensate and keep surface T the same due to energy conservation principles (neither created nor destroyed) in equilibrium which is supported by observation of short term thermometers and long term paleo derivation.

    Otherwise I think your numbers seem consistent with mine – while better explaining the transient phenomena. Thanks for that.

    ******

    Kristian 9:59pm: “You apparently missed the part where the diabatic loop ALSO involves convection..”

    There is no convection either externally out to space.

    Convection is implicit part of the adiabatic loop AND the diabatic loop but only IN the atm. Only radiation numbers get in/out from/to space so only radiation shown in the diabatic external loop eqn.

    Thought experiment: suppose conduction (or convection) did get externally to space? Get another term on the “out” side of the eqn. which is shown 0 now i.e. for +2W/m^2 with no increase in adiabatic loop (~my view) find:

    239 SW net in – (357+41-159) LW net out – 0 conduction out = 0 LTE in balance.

    159 = 335 – 80 – 17 – 78 – (1 missing heat)

    NB: For those interested & not asleep, the +2W/m^2 from atm. increased opacity means near surface global avg. Trenberthian temperature computes out to 289.4K with or without adiabatic speed up – increased from 289.1K base. So adiabatic speed up computes out to no effect on To in the simple model energy conserved balance of Fig. 15.

  161. Stephen Wilde says:

    “I’ve not used anything to do with allowing or not allowing lapse rate slope change, used nothing about volume.:”

    Then you can never get the right answer. Problem solved. You simply cannot ignore the energy throughput implications of expansion and contraction plus constantly varying real world lapse rates.

    “The slope of the lapse rate won’t change with reasonable surface temperature change b/c as you point out g and Cp are ~constant as is mass,”

    The IDEAL lapse rate doesn’t change and indeed cannot change if an atmosphere is to be retained but you missed the discussion about the difference between the IDEAL lapse rate set by gravity and the REAL WORLD lapse rates which vary all the time and everywhere in three dimensions as a result of a multitude of interacting forcing elements including radiative characteristics.

    On average, around the globe from surface to space the system must match the ideal lapse rate over time but it doesn’t need to do so (and indeed does not do so) anywhere in particular at any given moment.

    In order to make the mix of real world lapse rates net out to the ideal lapse rate the circulation changes as necessary and the atmospheric volume changes with the varying lapse rates to throttle the throughput so that over time the TOA radiative exchange is kept in balance.

    The adiabatic loop speeds up or slows down, gets larger or smaller to offset any forcing elements other than mass gravity and insolation.

    The crux is that due to events in the atmosphere involving different lapse rate slopes at different levels the real world lapse rates DO change with NO necessary change in surface temperature.

    Of course that cannot apply in a radiative scenario which requires the surface temperature as a baseline but you can only use that approach with no atmosphere. Add an atmosphere and that approach is invalidated.

  162. LeGrande Harris says:

    I think the big question here is what exactly is the equilibrium temperature for a given CO2 concentration at a given pressure? In other words what is the temperature point where KE and radiation balance, where an increase in temperature (KE) will force an increase in the GHG net out radiation?

    Just looking at the real world it seems to me that the Equilibrium temperature is around 25˚ C. At lower temperatures GHG’s increase the net energy going into the atmosphere and above 25˚ the KE in the atmosphere excites the CO2 causing a net energy loss due to radiation.

    [Reply] Degrees Celcius or Fahrenheit? At what location – surface or ‘effective emission level’?

  163. Stephen Wilde says:

    “I was nervous of double counting 2 to get 4, or 333 to 337 but it turns out not to be double counting”

    You were right to be nervous because it is double counting.

    Slowing down IR throughput by 2W/m is of opposite sign to speeding up the adiabatic loop by 2W/m

    You cannot add them together. They cancel out.

    You are stuck within the radiative requirement that the surface has to stay hotter to enable a faster adiabatic loop but it doesn’t.

    As fast as DWIR or adiabatic compression tries to add more energy to the surface it is whisked upward straight away because of the requirements of the pressure gradient.

    As David said, the pressure gradient provides a wide open ‘drain’ to space such that energy passing through spends no longer at the surface than before the increase in DWIR or adiabatic compression.

    It is time spent at the surface which determines surface temperature and that does not change except during periods of transition (which can be up to 1000 to 1500 years if one includes the thermohaline circulation).

    Which part of the concept of ‘throughput’ do you find difficult ?

  164. Trick says:

    Stephen 11:03pm: “You cannot add them together. They cancel out.”

    Watch the signs on the numerics Stephen, they are very instructive. Up is positive W/m^2. Down is negative W/m^2.

    If the adiabatic loop speeds up and the size increases get +2W/m^2 up into atm. 357+41 say.

    This means (-2W/m^2) comes down from atm. in adiabatic loop, right? It is adiabatic. Plus the (-2W/m^2) from Kristian’s “If more IR is coming down from the atmosphere.”

    Thus -333 goes up to -337 for energy conservation balance by the -2 down from increased adiabatic loop and -2 down from increased opacity atm. all by itself. They do NOT cancel.

    If no increase in adiabatic loop (my view), there is no -2 down from adiabatic loop.

    Thus in that case -333 goes up to -335 for balance -2 down from increased opacity atm. all by itself.

    In either case, neither have an effect on To. David is very demonstrably right in all this by pushing for the numerics.

  165. Trick says:

    Stephen 10:52pm: “Then you can never get the right answer. Problem solved.”

    But I did! Computed 289.1K global avg. atm. near surface. Problem solved. With all measured observed data!

    Missed To observed by less than 1K out of 289K. And my Poisson lapse rate plot of temperature profile up thru tropopause is only ~10% off from observed up there (it is exact at about 600mb). This is definitely close enough to get paid for government work unless you are trying to land a Mars probe in a 1km box. The rest of the 10% includes aerosols, forcings, & yes, 3D et. al. Not in the ground rules.

    Stephen continues “The IDEAL lapse rate doesn’t change and indeed cannot change if an atmosphere is to be retained but you missed the discussion about the difference between the IDEAL lapse rate set by gravity and the REAL WORLD lapse rates which vary all the time and everywhere in three dimensions as a result of a multitude of interacting forcing elements including radiative characteristics.”

    Yes, yes of course lapse rates really vary all over – for example, on a hot, sunny day in Phoenix at 2:00pm on asphalt might be 500K/km from your toes to your head. But all we are discussing here is Fig. 15. Please – as David asks – focus on that model ground rule simplification before going into real models which have lotsa’ issues as many agree.

    The numerics differ when Stephen says: “The adiabatic loop speeds up or slows down, gets larger or smaller to offset any forcing elements other than mass gravity and insolation.”

    Stephen – No, I just proved (again) David’s Fig. 15 numerics do not bear this out. There is nothing as yet that you have correctly pointed out to show the numerics have an issue. The numerics stand for the simple model of Fig. 15. Or correctly point out a numeric issue to discuss.

    That’s it for me unless there is a numeric issue discovered – let others carry on, please.

  166. Stephen Wilde says:

    “This means (-2W/m^2) comes down from atm. in adiabatic loop, right?”

    No, because you forget that:

    (i) More convection and wind carries water vapour up faster and in greater volume for radiation out at a higher level and causes more reflection back to space from more clouds.

    (ii) On a non water planet but with GHGs it carries up GHGs faster and in greater volume for more radiation out from a higher level.

    (iii) In a non GHG atmosphere (and in (i) and (ii)) it carries energy to the night side and back to the surface for faster radiation out from the surface on the night side.

    The adiabatic loop is merely a facilitator of other means of energy loss and retains the same amount of energy within itself but can both run faster and on the upward leg be laden with larger amounts of energy of other types such as latent heat or radiative energy within GHGs and aerosols.

    It will facilitate as much or as little energy loss as necessary to maintain TOA radiative balance over time.

    Your numbers are woefully incomplete due to your reliance on radiative processes and ignoring of mechanical processes.

    Nor have you addressed the problem of an indefinite cumulative energy gain from the radiative theory.

  167. Stephen Wilde says:

    “This means (-2W/m^2) comes down from atm. in adiabatic loop, right?”

    Nor do you realise that a higher expanded atmosphere will delay energy return to the surface thus leaving KE as PE for longer with a net cooling effect and a lower contracted atmosphere will do the opposite.

    In each case the delay or acceleration being capable of assisting in the process of offsetting whatever the net effect of CO2 might be.

    Throughput is the issue, not absolute values within a snapshot.

  168. suricat says:

    Trick says: February 25, 2013 at 9:46 pm

    “This is extremely important point to really “get”, I observe some posters miss this key text book point.

    On volume, you can pick any volume you want as I’ve said before, the atm. goes up to the last N2 molecule in orbit, the exact volume is pretty much undefined but not the density. That’s why atm. science uses P=density*R*T for atmospheres.”

    I’ll second that motion Trick! I’ve spent days in Part 1 trying to explain that density changes caused by ‘atmospheric water’ involve small temperature changes that generate greater volume changes than the temperature change would be credited with, but also involve large energy transfer. Namely, the effect of ‘latency’ in the atmosphere.

    The ‘Latent’ 80 W/m^2 is a ‘surface temperature depressant’ that adds nothing to ‘near surface atmospheric temperature’. This ‘figure’ (80 W/m^2) was calculated from the ‘atmospheric fallout’ of water as ‘precipitation’ (there’s a dualism here, not all rain reaches the surface to be counted as ‘precipitation’, but the value was assumed to be the ‘equivalent’ to ‘evaporation/evapotranspiration), but nothing is ‘counted’ in the ‘Latent’ figure for ‘Latent’ activity in Earth’s ‘atmosphere’. Something should be mentioned with ‘hind sight’!

    The mere existence of ‘clouds’ strongly suggests that Earth’s atmosphere is ‘supersaturated’ with ‘WV’ (water vapour). The fact that water exists as ‘cloud droplets’ in Earth’s atmosphere further extends the property of ‘Latency’ to Earth’s atmosphere.

    The ‘Latent 80 W/m^2’ is a ‘diabatic’ value that’s added to the atmosphere, where ‘Latency’ and ‘Radiation’ get completely confounded, confused, obfuscated, or ‘lost to observation’. We deserve more clarity on this object. ‘Latency’ confers the greatest volume change and energy transfer for a given mass than any other atmospheric process that I know

    Needless to say, I’m in Part 2 now. 😉

    Best regards, Ray.

  169. Trick says:

    Stephen 9:35pm: Didn’t you see the long flat spells capping the temperature with the only significant changes being Milankovitch cycles induced by changing energy coming in at TOA ?What do you think does that ?”

    Yes, I certainly did. How do you “know” Milankovitch is only significant? It is hard to resist commenting sometimes, as I ‘ve written before, Godot Act 2: “In the meantime let us try and converse calmly, since we are incapable of keeping silent.”

    What do I think? I am confident conservation of energy along with the 2nd law and Poisson lapse rate numerics would apply. What I don’t know is the albedo, emission, net insolation SW, net outgoing LW balance as there were no CERES et. al. satellites back then. But if there were, the existing at the time balance in Fig. 15 and the numerics would work just fine to find To within a Kelvin or so of accurate paleo derived surface T.

    There are even some reports atm. mass was significantly more back then enabling those pterodactyls to better fly in the denser air.

    “If the effect of the extra opacity (if not due to more mass) is not removed then radiation in will permanently be higher than outgoing radiation.”

    No, avg. surface temp. goes up to achieve new balance w/permanently higher avg. surface temperature, all local T varying around new balance for next 4bln yrs. or until an eon ends. The numerics tell the tale. Atm. has been retained doing this for 4bln yr.s.

    Stephen says: “Your numbers are woefully incomplete due to your reliance on radiative processes and ignoring of mechanical processes.”

    Where incomplete? – it is a simple model! How much? Precisely. What and how much do ignored mechanical throughput processes modify the numerics 17+80 (which I don’t ignore at all). Please show or ref. your better numerics that get even closer to surface T. Get even closer to observed trop. lapse rate. All with the simplified ground rules in David’s top post consistent with conservation of energy & 2nd law. Not just words which are so imprecise, go with David’s good point of using instructive numerics. If expanded atm. matters, show it in the numerics of top post. Delays don’t matter once get to LTE or show where/how much they do in numerics that balance.

    There is more to respond but I’ll let others like Ray have some bandwidth if they haven’t all lost interest or fled, ha. BTW I learned a lot from digging into texts due this & previous exchanges, thanks Stephen. And again tb for the bandwidth.

  170. suricat says:

    Trick says: February 26, 2013 at 2:01 am

    That sounds like a ‘eulogy’ Trick. Please say you’ll come back when we need you. 😦

    Best regards, Ray.

  171. Kristian says:

    Trick, you ARE double counting energy. You will just have to realize that. Because the atmosphere is NOT gaining more heat in your ‘2 more IR W/m^2 down from opacity’ scenario. It is gaining LESS from radiation and MORE from convection. The two balance out. 97+23 or 99+21, they BOTH amount to 120 W/m^2. Therefore there are no 2 W/m^2 of extra net energy (heat) from below to be added to your 2 W/m^2 of increased DLR from increased IR opacity. You claim the numerics speak for themselves. Apparently not. You got them wrong.

    Net IR radiation + convection only need to balance incoming net energy from THE SUN. If insolation does not increase, then outgoing from the surface won’t increase either (in the long term). Reducing one component (like net IR) only works to enhance the other (convection).

  172. Stephen Wilde says:

    Kristian said:

    ” It is gaining LESS from radiation and MORE from convection.”

    The MORE from convection, due to increased volume, goes to PE for a cooling effect which cancels the thermal effect of the initial change in radiative characteristics.

    There is no additional energy arriving at top of atmosphere and outgoing must match incoming so one cannot have a higher system temperature than is needed to match incoming.

    Anything other than mass gravity or insolation that tries to raise equilibrium temperature to a point where it would radiate out more than is coming in simply results in the excess going to more PE whilst the temperature remains around the initial level but subject to oscillations around the mean during constant periods of transition.

    Remember too that it is atmospheric MASS that counts most so even if there were residual thermal energy after the offset it would be utterly imperceptible.

    There is a reason why the temperature of the system has been so stable for so long.

    7000ppm of CO2 made no difference whatever to the achievable maximum temperature at the long term levels of mass gravity and insolation.

    Sensitivity to radiative characteristics would have led to a very different paleological record.

    Thanks to the efficiency of the water cycle as mentioned by suricat the system easily mitigated the effects of increasing solar power since the early faint sun.

    There are times when numbers are used to obfuscate simple logic.

  173. gbaikie says:

    “There is a reason why the temperature of the system has been so stable for so long.

    7000ppm of CO2 made no difference whatever to the achievable maximum temperature at the long term levels of mass gravity and insolation.

    Sensitivity to radiative characteristics would have led to a very different paleological record.

    Thanks to the efficiency of the water cycle as mentioned by suricat the system easily mitigated the effects of increasing solar power since the early faint sun.

    There are times when numbers are used to obfuscate simple logic.”

    So, we don’t live in the CAGW or Hansen Universe.

    But what caused the Little Ice Age?
    Or what could cause global trend of advancing glacier ice as serious as LIA or worse?

    It’s not the warming that seems to be a problem.
    More significant is what causes the cooling?

    Why we in something like a slow gradual 8000 year cooling trend?
    Or why hasn’t this interglacial been as warm as the past interglacial?

    Is just the sun and/or some somewhat large volcanic eruptions?
    Just chance.

  174. tallbloke says:

    Great to see this discussion so lively. Keep it coming.

    By the way folks, we made it to the Bloggies finals in the ‘Best Science or Technology Weblog’ category.
    https://tallbloke.wordpress.com/2013/02/26/bloggies-2013-tallblokes-talkshop-finalists-in-best-science-technology-category/

  175. Stephen Wilde says:

    “But what caused the Little Ice Age?
    Or what could cause global trend of advancing glacier ice as serious as LIA or worse?”

    Within the interglacial the primary forcing agent seems to be solar variations on a millennial timescale altering upper atmosphere composition (especially involving ozone) so as to change the global air circulation and global cloudiness.

    That then affects the amount of energy able to enter the oceans to fuel the climate system.

    But there is, again, a negative system response with the air circulation attempting to offset the thermal effect of such compositional changes forced by the sun.

    Compared to that the effect of our emissions comes nowhere.

    And then one has to add in the effects of ocean cycling, again on millennial timescales as regards the thermohaline circulation.

    And then consider the effects of changing phasing between solar and oceanic variations.

    In the end it is all just oscillations around the mean as the negative system responses smooth out a multitude of forcing elements as per my hypothesis.

    If any of that could lead to changes in equilibrium temperature as proposed for CO2 by some then we would already know all about it from a violent paleo record or, more likely, we wouldn’t be here.

    We are all just arguing about angels on pinheads. Once one appreciates the overwhelming contribution of the entire mass of the atmosphere then radiative characteristics become irrelevant anyway.

    David’s presentation identifies mass as the main issue, Trick seems to agree. What is left for CO2 to achieve given the huge variations either sde of the mean caused by sun and oceans ?

    Even if I were to concede a change in equilibrium temperature we could never see it from such a tiny system change.

    But the fact is that equilibrium temperature has obviously been impervious to all the vast challenges it has faced for 4 billion years due to the relative stability of atmospheric mass and gravity. Even the increase in the power of the sun has had little effect due to the power of our water cycle as a negative system response.

    Variations in the radiative characteristics of trace gases as a significant aspect of the climate system is a laughable proposition.

  176. Stephen Wilde says:

    Is there to be a Part III or some sort of conclusion ?

  177. tallbloke says:

    Stephen, Of course. It’ll be written by a committee formed of the protagonists and no-one will be allowed to leave until all are agreed. That should force a settlement before we all grow beards.

  178. Trick says:

    Kristian 6:56am: “Therefore there are no 2 W/m^2 of extra net energy (heat) from below to be added…”

    I agree with Kristian there is no extra 2W/m^2 of extra net energy from below; in making this point puts serious doubt into Stephen’s assertion the adiabatic loop speed and size change exactly to cancel any change in the diabatic loop. The monthly anomaly and paleo record variations do not support Stephen’s assertion either. David’s simple model numerics in Fig. 5 (I wrote Fig. 15 above really meaning Fig. 5 top post) just do not support Stephen’s assertion.

    Stephen has offered no numerics to support his assertion, just more assertions.

    IMO the approach Stephen should take is asserting albedo changes might cancel diabatic loop changes to To. That’s why they need GCMs, have to go beyond simple Fig. 5 m^2 column. David’s top post doesn’t include “albedo throttling” on the input side which has a very powerful affect on the To numerics. The GCMs seek to find albedo deltas in the midst of chaos. So far only finding controversy IMO.

    ******

    Ray: “That sounds like a ‘eulogy’ Trick..”

    LOL, just a concession to let other inputs surface, if any, to discuss my view of the numerics “If more IR is coming down from the atmosphere…” 2/25 7:20pm or once again:

    …if Stephen’s adiabatic loop does not speed up much if at all (my view):

    Adiabatic loop stays roughly the same:

    80+17 = 97

    Diabatic loop increases avg. surface temp. from 289.1K to 289.4K from the 2W/m^2 modeled extra emission coming down radiated at surface from lower atm. in Fig. 5 constant energy balance say split evenly between window and atm.:

    239 SW net in – (357+41-159) LW net out = 0 LTE in balance.

    159 = 335 – 80 – 17 – 78 – (1 missing heat)

    The 333 only then need go to 335 for balance by 2W/m^2 emitted from atm. all by itself. Of course, the adiabatic loop processes may change a bit causing the 333 go up a bit more than 335, depending on what flavor of lapse, albedo, emission or balance you like. Just need account for energy conservation in the numerics.

    ******

    tallbloke 2:21pm: “…no-one will be allowed to leave until all are agreed.”

    Insert smiley face here. Predict Part 3 will lead to Part 4 until the whole text book is agreed.

  179. Stephen Wilde says:

    “IMO the approach Stephen should take is asserting albedo changes might cancel diabatic loop changes to To.”

    That is already implicit in the issue of circulation changes as one of the many consequences of increased uplift, descent and horizontal wind flows.

    I seem to recall making that clear to Trick some time ago.

    Mind you I’m puzzled as to why Trick doesn’t accept that even increased surface windiness would prevent a surface temperature increase.

    Sea breezes come to mind. Once a flow of air develops it clearly brings down the temperature of the surface below.

  180. Trick says:

    Stephen:: “I’m puzzled as to why Trick doesn’t accept that even increased surface windiness would prevent a surface temperature increase.”

    Accept breezes affect local T only. Where the breeze came from, the other local T offsets for no change in the global spatial and temporal sampled averaged To. The m^2 column of Fig. 5 would have “breezes” with no affect on its spatial and temporal sampled avg. To in LTE. Verkley paper discusses the details.

  181. Stephen Wilde says:

    “Accept breezes affect local T only”

    Not if the entire global wind speed is faster both vertically and horizontally such as on Mars where the winds can create planet wide dust storms.

    Martian winds are strong relative to atmospheric density because in the absence of water vapour they have to work harder to retain equilibrium.

    Funny how Trick asserts that equilibrium temperature MUST rise to support his radiative theories but that equilibrium temperature CANNOT fall just as much from changes in circulation.

    He attributes significance to changes in radiative characteristics but near zero significance to circulation and volume changes.

    Appeals to simple logic don’t work because he then calls for numerical evidence and puts forward flawed numbers where the component features are incorrectly applied.

    Adding together a warming and a cooling process as if both were warming processes is a strange approach.

    Leaving out the thermal effect of a higher atmosphere converting more of the available KE to PE is another.

  182. gbaikie says:

    “We are all just arguing about angels on pinheads. Once one appreciates the overwhelming contribution of the entire mass of the atmosphere then radiative characteristics become irrelevant anyway.

    David’s presentation identifies mass as the main issue, Trick seems to agree. What is left for CO2 to achieve given the huge variations either sde of the mean caused by sun and oceans ?”

    I think the most [as upper limit possible] is if CO2 doubles [800 ppm] we could see increase in global temperature by 2 C. Which would mostly in nighttime and winter temperatures- and I don’t see a downside to that.
    But I think the fingerprints from increased global CO2 is not visible- it wasn’t apparent in the 1980’s
    and not apparent at the present.
    And much of greenhouse effect theory is pseudoscience.

    But there does seem to be correlation to increased warming and elevated CO2 level in the palo record- global CO2 levels seem to follow warming.
    On lower scale of estimate, it seems doubling may be less than .5 C to warming. Likewise
    I don’t see much evidence that CO2 causes cooling so maybe as much as .5 C in cooling from
    such doubled CO2 levels.

    If we knew we were entering a cooling period, I wouldn’t think adding CO2 or any greenhouse gas
    would be effective to prevent such cooling.
    I suppose the best solution to prevent cooling would to blacken the snow of the advancing glaciers- as most immediate type of solution. Make them greyish rather then black.

    And adding water desert regions could also make small effect- would take longer and would cost more, but you could make the land more productive and valuable- so it’s an investment type-
    and it’s mostly a matter of applying good politics. Since UN lousy at politics, one have to have good local and global leadership to do this properly.
    But both these seem like they would only have a minor effect.

  183. gbaikie says:

    ” Stephen Wilde says:
    February 26, 2013 at 2:50 pm

    “IMO the approach Stephen should take is asserting albedo changes might cancel diabatic loop changes to To.”

    That is already implicit in the issue of circulation changes as one of the many consequences of increased uplift, descent and horizontal wind flows.

    I seem to recall making that clear to Trick some time ago.

    Mind you I’m puzzled as to why Trick doesn’t accept that even increased surface windiness would prevent a surface temperature increase.

    Sea breezes come to mind. Once a flow of air develops it clearly brings down the temperature of the surface below.”

    If you had parking lot and it’s very hot afternoon, and one could fire hoses and sprayed it down- you going cool down the area really quickly and perhaps keep the parking lot cool for rest of the day.
    So it makes parking lot cooler. But it’s adding warmth to atmosphere. And if entire city did this- it still cool entire city- but would increase humidtiy. If this was done before noon- it’s possible
    it would little effect upon daytime highs and large effect upon humidity- make the city uncomfortably warm. And this basically occurs by daily watering the all the lawns in the morning- and would be part of UHI effect. But if did on all pavement the effect should be greater.

    Anyways, if the wind is cooling the surface, it’s taking away heat which would would be radiated, and warming the entire atmosphere.
    So, say without wind, the surfaces is 60 C, and with the wind the surface is 40 C and some large body of air is warmed by 1 C. I seems that the 60 C surface would radiate more energy into space
    than the 1 C warmed air.

    So maybe this could way to add to global warming, have all cities when it’s warmer, water their all their pavement at say 11 am. And repeat at 2 pm so city inhabitants feels less hot- and adding more heat to atmosphere.
    It would use a lot of water, but could use non smelly but brackish or salty water- on pavement.

  184. LeGrande Harris says:

    My question just recieved a question : ) So I will try again with a different tack.

    Let’s assume this model has no GHG’s and the atmosphere is completely transparent to short and longwave radiation. The only heating and/or cooling of the atmosphere is from the surface via conduction.

    The atmosphere will gradually heat up with the hottest most energetic molecules rising to the top of the atmosphere. Eventually the atmosphere near the surface will equal the S-B equation and start raising the average temperature of the earths surface. At some point an equilibrium temperature will be reached with an extremely hot upper atmosphere and a much hotter world. The opposite of our current lapse rate.

    Now if we inject a radiating absorber/emitter gas to the atmosphere the intial effect will be to decrease the atmospheres temperature via kinetic translational effects to the gas. The effect will be greatest at the top of the atmosphere and lowest at the bottom of the atmosphere. Eventually the atmosphere will have the standard lapse rate of being warmer at the bottom and colder at the top.

    The question then to me, is at what temperature and pressure (at a given radiation level) is a greenhouse gas like CO2 in equilibrium i.e. no net heating or cooling of the atmosphere. I don’t think the cocentration of the radiating/absorbing gas matters except that it affects the rate of heating or cooling.

    My guess (based on living in the tropics) is that at sea level (one atm), at the equators insolation from the Sun, the equilibrium temperature for H2O in the atmosphere is apx. 25˚ Centigrade. Below 25˚ C H2O’s net effect is warming and above 25˚ C the net effect is cooling. I am guessing (based on the molecular size) that CO2’s Equilibrium temperature and pressure in the atmosphere is different : ) but I don’t know enough Quantum Mechanics to figure it out and a cursory search hasn’t provided any definitive answers.

    Obviously if I am correct increased levels of CO2 only result in warming up to the equilibrium point and cooling above that point, and GHG’s are primarily responsible for the lapse rate in the atmosphere.

  185. gbaikie says:

    “The atmosphere will gradually heat up with the hottest most energetic molecules rising to the top of the atmosphere. Eventually the atmosphere near the surface will equal the S-B equation and start raising the average temperature of the earths surface. At some point an equilibrium temperature will be reached with an extremely hot upper atmosphere and a much hotter world. The opposite of our current lapse rate.”

    We have an extremely hot upper atmosphere, but it’s very low density gas. Or it’s not a nearly perfect vacuum- such as found most of the space in our solar system [or the surface of the Moon].
    Or Earth’s atmosphere extends up to 800 km from the surface. Stuff in low Earth orbit is fly through
    this atmosphere [and has a small amount of drag caused by flying thru this very thin atmosphere].
    So there is the the zone called the thermosphere:
    “The thermosphere is the layer of the Earth’s atmosphere directly above the mesosphere and directly below the exosphere. Within this layer, ultraviolet radiation (UV) causes ionization. Called from the Greek θερμός (pronounced thermos) meaning heat, the thermosphere begins about 85 kilometres (53 mi) above the Earth. At these high altitudes, the residual atmospheric gases sort into strata according to molecular mass (see turbosphere). Thermospheric temperatures increase with altitude due to absorption of highly energetic solar radiation. Temperatures are highly dependent on solar activity, and can rise to 2,000 °C (3,630 °F). Radiation causes the atmosphere particles in this layer to become electrically charged (see ionosphere), enabling radio waves to bounce off and be received beyond the horizon. In the exosphere, beginning at 500 to 1,000 kilometres (310 to 620 mi) above the Earth’s surface, the atmosphere turns into space.”
    http://en.wikipedia.org/wiki/Thermosphere

    So, ISS is flying most of the time in the thermosphere and sometimes going as high as the beginning part of the exosphere. The moon has a better vacuum then the region the ISS flies thru.
    And making vacuum as good as what ISS flies thru is somewhat difficult to do, I think has been done for various purposes, but not Moon like vacuum conditions.
    So ISS flies thru a good vacuum but there is still atmosphere gas up there, and the gases traveling at a high velocity and they collide with each other- so they are very hot, but they aren’t going warm
    a thermometer. So measuring heat with a thermometer is not any different than the most of vacuum in the solar system.

    But as you lower in the atmosphere the gas molecules collide with other gas molecules. And once get lower enough that one get more collision per second, rather than minutes, hours or days,
    one begins to gets some lapse rate. But one also has a sorting of molecules, because the faster molecules go further before collision and therefore stay longer up. Slower molecules hit more often per distance travel, thereby increasing the chance of them going downward.
    So fastest stay up, or they hit replacement molecule which in turn stays up. But even if at orbital velocity, they don’t say there forever- the only way get to be up *forever* is escaping earth’s
    gravity.
    To have orbital velocity they need to travel at 7.8 km/sec and escape velocity is 11 km/sec. and gas molecules in most of the mass of atmosphere [troposphere] is traveling at 0.4 km/sec.
    Or if a gas molecule is traveling at 7 km/sec, it’s in suborbital trajectory- it will within about an hour hit a another gas molecule or the earth’s surface.
    So very very hot gas leaves earth, and slow moving molecule at say 50 miles up, can collided much faster molecule, and then it can leave earth.
    Though a molecule in the troposphere being hit by molecules going really fast, say 100 km/sec is unlikely to leave earth, because other gas molecule will hit it and velocity will average out among millions to billion of molecules.

    So if follow your ever increasing high upper atmosphere temperature, unless we talking over 7 km/sec the molecule are falling in suborbital trajectories. If higher than 7 km/sec there are going to kick each other into escape trajectories.
    [But no furnace has gas molecules travel faster than 5 km/sec, unless some kind of vacuum/plasma furnace- cause it would melt anything at sea level pressure.
    So one could iron gas atmosphere and have lower velocity than about 5 km/sec- so temperature above Venus].
    So with your suborbital velocity gas, it going to hit other gas which lower, and one will higher density gas near the surface. And higher density gas will be averaging it velocity with itself and the surface temperature. And basically one can’t have more heat [total heat capacity of gas molecules
    in the lower atmosphere, because it balance it’s heat to the lower gases. Or these hot gases can not avoid contacting the lower gases and transferring the their heat.

    They playing dice against the house- they can not get much energy from lower gases and lower gas can get more energy from the faster moving molecule- it’s rigged against the faster molecules.
    So upper atmosphere is very hot, but there is very few of them- the total amount heat is insignificant compared to the much more numerous much cooler lower elevation gases.

  186. wayne says:

    gbaikie, wouldn’t you then maybe say that the energy density always remains the same or decreases with height even though above the stratosphere the temperature is rising? I can see that, roughly, though don’t know if it is empirically correct. Temperature is rising as the density is dropping. Don’t think I’ve ever seen that relationship on a graph or table.

  187. Max™ says:

    Stephen, Of course. It’ll be written by a committee formed of the protagonists and no-one will be allowed to leave until all are agreed. That should force a settlement before we all grow beards.” ~tallbloke

    Too late, already got one!

    I say you should dwarf fortress it up a little, no one can leave without a conclusion, or we pull the lever and flood the place with magma!

  188. Trick says:

    Max 12:13am: Yes of course to dwarf fortress it up, I conclude “heat flow throttling” is really atm. opacity. Flood it & let solidify. Move on to Part 3 input side “albedo throttling”.

    But not before this response:

    ******

    Stephen 3:42pm: “…Trick asserts that equilibrium temperature MUST rise to support his radiative theories…”

    I don’t just assert equilibrium temperature MUST rise with +2W/m^2 from Kristian’s “If more IR is coming down from the atmosphere…”, it is proved based on applying 1st law consistent numerics for Fig. 5.

    Stephen continues: “…but that equilibrium temperature CANNOT fall just as much from changes in circulation.”

    David’s Fig. 5 has constant energy flux density in and out; Fig 5 is at equilibrium. Draw a circulation arrow in the green box for L&O. The arrow doesn’t bring energy in or let energy out if drawn properly. So equilibrium temperature cannot fall OR rise due to circulation in L&O or even atm. in David’s “heat flow throttling” simple, basic but intelligent model.

    “(Trick) attributes significance to changes in radiative characteristics but near zero significance to circulation and volume changes.”

    Not near zero, exactly zero since circulation and volume doesn’t change without energy added in or taken out of David’s Fig. 5 equilibrium model.

    “Appeals to simple logic don’t work because he then calls for numerical evidence and puts forward flawed numbers where the component features are incorrectly applied.”

    Stephen’s assertion above:

    “…the adiabatic loop is variable in speed and size and so can influence atmospheric volume whereby KE can be shuffled to and fro to PE and back to keep the temperature of the entire system just right …”

    If “just right” means constant To as Stephen asserts elsewhere, this is shown 1) by modern text book physics to contain flaws and 2) shown not consistent with observations since adiabatic loop isn’t variable in speed or size w/o extra energy once simple, basic numerics are used to account for energy conservation. If my numerics are flawed or energy is not conserved please discuss using numerics not assertions just where the flaw exists exactly, the proof again:

    Adiabatic loop: 80+17 = 97, no change w/o extra energy in or out

    Diabatic loop increases avg. surface temp. from 289.1K to 289.4K for balance from the 2W/m^2 modeled extra emission coming down radiated at surface (333+2=335) from bulk of well mixed lower atm. in Fig. 5 constant energy balance say split evenly between window and atm.:

    239 SW net in – (357+41-159) LW net out = 0 LTE in balance.

    159 = 335 – 80 – 17 – 78 – (1 missing heat)

    NB: Need to offset the +2W/m^2 radiated down from lower atm. for energy cons., so the upper troposphere and/or stratosphere become -2W/m^2 or 0.3K cooler avg. over the spectrum conserving energy. Same volume, same Poisson lapse rate, same energy in Fig. 5 starting from new To=289.4K at Po.

  189. suricat says:

    Stephen Wilde says: February 26, 2013 at 7:42 am

    With all due respect Stephen, why don’t you include ‘latency’ as a part of your ‘theory’? It really does enhance ‘volume’ where ‘energy exchange’ is apparent and temperatures are relatively unaffected.

    Best regards, Ray.

  190. suricat says:

    Further to my last post Stephen.

    Why do you ignore any ‘forcing’ of ‘latency’ to your hypothesis?

    This is just a re-affirmation to the conundrum of why you ignore the activity of the atmospheric hydrological cycle.

    Best regards, Ray.

  191. tchannon says:

    “LeGrande Harris says:

    The atmosphere will gradually heat up with the hottest most energetic molecules rising to the top of the atmosphere.”

    Molecules have mass. What is going to lift them against gravity?

    You’ll end up inventing convection. And mixing. And a particular lapse rate. And wind.
    It’ll go chaotic, cells and so on.

    On the other hand there is night. Gets fun then.

  192. Stephen Wilde says:

    suricat.

    Not sure what you mean by “latency”. Normally latency is synonymous with delay.

    If you mean latent heat then I have made it clear that it is an accelerant of upward energy transfer and so helps as a negative system response to remove the effects of factors that try to decelerate energy transfer such as the proposed influence of CO2.

    As regards the hydro cycle I am on record as having given it substantial recognition as a negative system response.

    I have also acknowledged the effect of latent heat in pushing up the tropopause and thus increasing volume as part of a faster adiabatic loop.

    Trick.

    The fundamental flaw with all your numbers is that when you add or subtract energy to the surface you are just applying the equations relevant to an increase or decrease in energy coming in from outside the system. Therefore you will get a rise in equilibrium temperature.

    Those equations do not apply when energy is simply redistributed within the atmosphere because once beneath an atmosphere the surface temperature is set by by pressure and density at any given level of energy coming in from outside.

    If energy from outside stays the same and pressure stays the same then the only available system response to more energy in the atmosphere is a change in volume but that results in a change in density if mass stays the same too.

    A change in volume and the consequent reduction in density prevents a rise in surface temperature.

    Therefore your numbers are simply inapplicable.

    One must instead apply the Gas Laws in the way I suggested previously and the only way one can stop the surface temperature rising when more energy is retained by an atmosphere without more coming in from outside is by shifting the available KE to PE so that it does not register on sensors as temperature.

    That is exactly what the increase in volume achieves.

    It really is as simple as that.

    End of Part II

  193. Stephen Wilde says:

    Here’s a little play with Trick’s numbers.

    At equilibrium, 100 units of energy come in and 100 units go out.

    GHGs come along, absorb some of the outgoing energy and radiate 2 units back to the surface. Trick doesn’t offset that extra 2 units to the surface with any blocking function from GHGs so we can ignore that.

    The surface now receives 102 units and warms up accordingly.

    The warmer surface must radiate out more than before so at top of atmosphere 102 is leaviing but we still only have 100 coming in.

    More going out than coming in results in cooling doesn’t it ?

    A higher equilibrium temperature can only be sustained if more is coming in at TOA as well.

    If it doesn’t then no higher equilibrium temperature.

    That follows from radiative physics.

    BUT there is indeed more energy in the atmosphere because those GHGs are absorbing more so what happens to it ?

    Apply the Gas Laws.

    The volume of the atmosphere expands and converts it to PE for no change in surface temperature.

    In the process of changing atmospheric volume the global air circulation changes.

    That change in circulation CAN affect albedo which alters the amount of energy entering the oceans but the atmospheric volume and circulation change again to neutralise oceanic effects too.

    If solar effects change upper air chemistry the same negative system response applies.

    If only 100 units are coming in then only 100 units can go out and any discrepancy meets an equal and opposite system response.

    Voila.

    An amalgamation of radiative physics with the Ideal Gas Law that fits observations, common sense and basic physics.

    During periods of transition from one potential equilibrium state to another the atmosphere simply expands and contracts as necessary to maintain TOA energy balance within a narrow range.

  194. Stephen Wilde says:

    Trick could say that the effect of CO2 is reduce the radiating temperature to 98 units so that the temperature must rise to restore outgoing at 100 units.

    The problem with that is as I told him before namely that due to the repeated effect of the CO2 on each successive energy escape attempt one would never get the whole 2 units out at any level of increased temperature.

    There would always be a residue retained with ever increasing temperature in an indefinite positive feedback loop.

    Eventually no atmosphere.

    In theory even 1 GHG molecule could cause loss of atmosphere given enough time.

  195. Trick says:

    Stephen 9:19pm: “The warmer surface must radiate out more than before so at top of atmosphere 102 is leaviing but we still only have 100 coming in. More going out than coming in results in cooling doesn’t it?”

    No. Just do the simple arithmetic Stephen. There is not 102 leaving – that would mean energy is created somewhere in David’s Fig. 5 and that goes against 1st law as you know so there is still 100 going out. Here’s the equilibrium with the +2W/m^2 from Kristian’s proposal:

    239 SW net in – (357+41-159) LW net out = 0 LTE in balance.

    239 – (398-159) = 0

    239 LW in – 239 SW out = 0 averaged over the spectrum

    Divide by 239 if you wish to make it unit:

    100 in – 100 out = 0

    See, not 102 out, 1st law stands consistent, numerics are much better science than word assertions.

  196. Trick says:

    Ha, 239 SW in – 239 LW out = 0 averaged over the spectrum

  197. Stephen Wilde says:

    Trick.

    You can’t have a higher surface temperature AND a change in volume because of the cooling effect of the reduction in density.

    As regards the numbers, you certainly can have more than 100 going out during the period required to cancel out the effect of CO2 and bring the system back to the initial temperature.

    No breach of the 1st Law. Simply a change in flow rate in one place to cancel out a change in flow rate elsewhere.

    But you don’t understand ‘throughput’ do you ?

    It is all instant for you because radiative transfer is at the speed of light.

    You want the system to be able to rise to a higher temperature than needed to achieve energy balance at top of atmosphere without energy out then exceeding energy in AND without any expansion of the atmosphere.

    That would be a breach of the 1st Law.

  198. Trick says:

    Stephen 12:52PM: “You want the system to be able to rise to a higher temperature…”

    I want to get the science right & to see through word assertions. The “system” does not rise in avg. temp. Stephen as I wrote above that takes more energy than Fig. 5 has, the lower atm. is slightly warmer under Kristian’s proposal and the upper atm. is slightly cooler. No energy harmed or created, no “system” avg. volume change, no lapse rate change, no “system” avg. temperature change with Kristian’s proposal; this is what the numerics say and the scence shows – not what I “want” for the system.

    So what the heck, under Kristian’s proposal my vegetable garden might be on avg. a bit more productive this year than 200 years ago. There are wins and losses. Life & nature are like that. For eons. You never stay the same, you either get better or you get worse. Be an optimist.

  199. Stephen Wilde says:

    What must happen is that any reduction in energy loss to space causes an expansion in atmospheric volume.

    An expansion in volume allows energy to flow through faster due to the lower density so as to keep energy in at 100 and energy out at 100 with temperature staying the same.

    There are time lags from multiple forcing elements internal to the system so that for short periods the energy out can be a little above or a little below the energy in with commensurate short term changes in temperature.

    In fact don’t your figures take that into account by netting out to zero ?

    If you were to factor in the thermal effect of a rise in surface temperature then you would have to alter all the numbers proportionately which would no longer produce TOA balance.

  200. Stephen Wilde says:

    “the lower atm. is slightly warmer under Kristian’s proposal and the upper atm. is slightly cooler.”

    So the volume of the lower atmosphere becomes slightly greater (lower density offsetting the warming) with more of its KE converted to PE and the volume of the upper atmosphere becomes slightly smaller (higher density offsetting the cooling) with more of its PE converted to KE.

    The tropopause rises a bit. Circulation changes occur exactly as per my hypothesis because amongst other things the greater temperature differential between lower and upper atmospheres speeds up the adiabatic loop.

    Both layers stay at exactly the same temperatures as before but at different volumes.

    You can’t keep TOA balance any other way.

  201. Stephen Wilde says:

    Going a little further it wouldn’t keep the TOA radiative balance stable if one were to cool the upper atmosphere to balance a warming of the lower atmosphere.

    Most radiation going out to space comes from the surface so warming the surface in the way proposed by Trick would immediately have too much energy leaving the system from the raised surface temperature.

    As per S-B, radiation is proportionate to temperature so a higher surface temperature must result in more outgoing. It cannot be offset by a cooler upper atmosphere because mostly it goes straight through to space.

    The excess going out would very soon reduce surface temperature to the initial level.

    In truth, no rise in surface temperature occurs at all due to volume and circulation adjustments but if it did then TOA balance would be out of sync and the entire system would cool back to the initial level anyway.

  202. Genghis / LeGrande Harris says:

    I am obviously doing a poor job asking my question : ) So I will try again, maybe it will help me understand it better too.

    When a CO2 molecule absorbs a photon it becomes charged and more energetic and it may either hit another molecule and lose the energy via KE transfer or it may emit another photon. Also if another molecule with more KE hits the CO2 molecule transferring KE back to the CO2 molecule the CO2 molecule may emit a photon or transfer the KE along. Pretty basic QM stuff.

    If the parcel of air is cold, most of the collisions will be caused by the CO2 molecules absorbing photons and then transferring that energy to the other molecules as KE and also reemitting the photons. That causes the CO2 molecules to have a net warming effect.

    If the parcel of air is hot, the other energetic particles will transfer their KE to the CO2 molecule where the energy is primarily lost via photon emission. In this case, CO2 has a net cooling effect.

    Someone, somewhere should have a nice clean graph showing the equilibrium temperature, pressure and insolation values for CO2 in a dry atmosphere. Ditto for H2O, which I am guessing is around 25˚ C at standard atmosphere at the equator.

  203. Stephen Wilde says:

    Genghis.

    Very true, which is why some of us say that the net thermal effect of CO2 is unclear.

    My point is that it doesn’t matter much either way because volume and circulation changes remove whatever effect they have, if any.

    Trick thinks they have a net warming effect on the lower atmosphere and net cooling on the upper atmosphere.

    I’m not aware of any such graphs but there is evidence of a cap on the temperature of our watery planet at 25C.

    Since equilibrium temperature and pressure numbers rely on mass I don’t think anyone has looked at the effects of types of molecules individually but if some are now saying that radiative characteristics are more important than mass then they should produce such graphs to prove it.

  204. Kristian says:

    Stephen Wilde, you say: “The surface now receives 102 units and warms up accordingly. The warmer surface must radiate out more than before so at top of atmosphere 102 is leaviing but we still only have 100 coming in.”

    No. This is where the confusion arises. If you conflate one-way energy fluxes with net fluxes you easily end up double counting the energy flows.

    If the surface receives 2 more units of energy than before, that means the NET flux UP is reduced (by 2 units). The ONE-WAY upward flux is however NOT reduced. Because the temperature has not yet risen. This means 100 units are coming in and only 98 are going out, but the temperature (in this initial condition) remains the same (so same flux as before (396)).

    The surface then needs to raise its temperature to increase the thermal emission –> 398. When this is achieved, the balance is regained – 100 IN and 100 OUT.

    All this WOULD work if the surface could only rid itself of heat through radiation. But this is not the case. So it will NOT happen. What happens instead when 2 more units of energy is deflected back down to the surface (100 IN, 98 OUT), for the Earth system to regain energy balance, convection strengthens – more energy is lifted by convection from the surface to the tropopause from where the excess heat is radiated off to space (100 IN, 100 OUT). No discernable rise in surface temperature results.

    It is after all not the surface temperature that needs to be regulated if the internal energy flow of the atmosphere changes. It is the internal energy flow itself. If 2 units of energy is somehow hindered on its way from surface to outer space, then the system needs to adjust accordingly. 100 units IN, 98 units OUT. Enhanced convection closes the gap. If the surface tries to raise its temperature in response to reduced radiative heat transfer, then convection simply strengthens, increasing the cooling rate back to where it were and the surface temperature drops back. How is this accomplished? As soon as more IR is coming down from the atmosphere, the net IR flux from surface to air is reduced. This means the already warmer surface keeps more of its absorbed energy and will raise its temperature ever so slightly. At the same time, though, the air above will gain equally less energy from the ground (because its being held back), and the already cooler air will cool ever so slightly. This leads to an increased temperature gradient between surface and air layer. And this in turn promotes … enhanced convective heat transfer.

    So, to reiterate what has already been said before, thermal radiation is only a function, a result of the temperature (and specific emissivity) of the body emitting it. It is not a cause of that temperature. Therefore, the Earth’s upward surface IR emission (ULWR) will only increase if the surface temperature rises. Not by an increase in DLWR. It is the temperature rise that results in increased emission. Not the change in incoming flux itself. Convective flow, on the other hand, between two bodies at different temperatures is not related to the specific temperature of any of those two bodies. It is related directly to the temperature DIFFERENCE between them.

    In other words, when radiation tries to raise the surface temperature it ‘inadvertently’ parallelly increases the temperature gradient between surface and air. The two effects cancel each other out.

    This is why a hypothesis of GHE (and AGW) cannot claim surface warming by ‘back radiation’, because this only affects one of the cooling mechanisms at hand. It has to find a mechanism which restricts the TOTAL cooling process of the surface, that is radiation PLUS convection. This can only be achieved by reducing the temperature gradient from surface to air/atmosphere. And this is where the ERL mechanism comes in. So far, however, even this only works in theory.

  205. Stephen Wilde says:

    Kristian.

    I was actually criticising the double counting implicit in the standard AGW scenario.

    That scenario suggests surface warming but then denies that surface warming should result in more energy radiating out.

    I clarified the point in my next post at 9.57 am.

    We are agreed that:

    “In other words, when radiation tries to raise the surface temperature it ‘inadvertently’ parallelly increases the temperature gradient between surface and air. The two effects cancel each other out”

    It is the volume change that alters the temperature gradient so the rest of my comment appears to be correct and in accordance with your position.

    It has long been my contention that circulation changes altering the rate of convection and the speed of the water cycle prevent an increase in surface temperature from GHGs.

  206. In my opinion, the only way to have a coherent discussion about the mechanisms that may or may not cause Atmospheric Thermal Enhancement is to talk ‘steady state’. That’s what my simple energy diagrams are all about.

    Steady state means…er…steady state. In particular it means no changes in temperature; no changes in CO2 concentration; no changes in average cloud coverage; no Milankovitch cycles; no ice ages; and no weather. In fact, no anything – except a nice fixed unchanging 199Wm-2 flow of energy up the atmospheric convective column towards space!

    Yet the last 48 hours of discussion has almost all been about changes: Milankovitch cycles. Ice ages. Temperature changes, here or there, up or down. Changes in albedo. Changes in volume (whatever that means) You name it, you have discussed changing it.

    I’ve kept out of it.

    I suggest that we should now refrain from looking at changes and get back on track – which is to examine in detail the two physical mechanisms that may be responsible for the earth’s surface temperature being at a steady state level that is several tens of degrees C above that of an airless planet.

    Only when we understand the mechanisms that sustain the ATE under that steady state scenario will it be time to ask how sensitive those same mechanisms are to changes in CO2.

    On February 25, 2013 at 3:36 pm above, I calculated the ‘effective conductivity’ of the convective atmosphere as being:

    Katm = 33,729Wm-1K-1

    and posed the question of whether this was caused mainly by the mechanics of the convective process on the way up or by the behaviour of the radiative gases at the top.

    I am afraid Konrad is away until next week. But Tim Folkerts, are you hiding somewhere?

    The world awaits… 🙂

    DC

  207. Genghis says:

    Stephen Wilde said, “I’m not aware of any such graphs but there is evidence of a cap on the temperature of our watery planet at 25C.

    Since equilibrium temperature and pressure numbers rely on mass I don’t think anyone has looked at the effects of types of molecules individually but if some are now saying that radiative characteristics are more important than mass then they should produce such graphs to prove it.”

    I think that is the whole point of the AGW argument Stephen, that CO2’s radiative characteristics dominate.

    It appears to me though that GHG’s heat up the atmosphere only up to equilbrium and then they cool the atmosphere. It also appears to me that the equilibrium temperature is very close ( less than ) to the temperature under the noon day sun in the summer. The temperature oscillates around the equiibrium temperature.

    I agree that mass is critical to the temperature, but that the GHG’s act primarily to cool the mass down to the equilibrium temperature. I think the simple CO2 experiments in a box illustrate the point. The AGW’ers simply look at the experiment up to the equilibrium point and then stop, not realizing that the CO2 is actually setting an upper limit.

  208. Trick says:

    David 3:46pm: “Yet the last 48 hours of discussion has almost all been about changes:…”

    The only discussion of “change” from me is the one Kristian proposed which for “heat flow throttling” is an example exactly on topic since “throttling” implies a change to atm. energy flux density flows at equilibrium steady state.

    Stephen 1:20pm “Both layers stay at exactly the same temperatures as before but at different volumes.”

    The numerics show this is not the case Stephen due to energy conservation accounting. 100in = 100out at higher lower T and lower upper T conserving energy. Stephen should show his reasoning with numerics consistent with 1st law to be believed and discuss from & show 1st principles not simple assertions. My Prof.s always wanted me to show my work too.

    Stephen continues: “Trick thinks they have a net warming effect on the lower atmosphere and net cooling on the upper atmosphere. I’m not aware of any such graphs.”

    I know since it is the simple, basic science of Fig. 5 shows me this is the case. The lapse profile graphs proving it with energy conservation are in the Verkley paper posted here and discussed many times; past posters tried to make Stephen aware. They are also in modern texts. Take a close look Stephen at the Verkley Fig. with the Poisson lapse rates plotted from energy conservation numerics; I’ll even walk you through it if you ask. Very elegant proofs are available with graphs showing how Kristian’s proposal works in meteorology.

    Remember you can get any atm. volume change Stephen desires just by moving that highest N2 molecule still in orbit up and down whatever distance Stephen asserts. This method of reasoning carries no information which is why can assert anything Stephen wants about atm. volume & why Stephen won’t find volume used in atm. science.

    Not good enough to just assert Stephen, show your volumetric work. For instance Stephen asserts 7:46am:

    “…the surface temperature is set by by pressure and density at any given level of energy coming in…”

    Show Stephen’s work proving this assertion with simple, basic numerics as I’ve shown mine.

  209. Stephen Wilde says:

    Volume is used in the Gas Laws.

    I don’t need to reinvent the wheel.

    In the meantime we must await Part III which may deal with changes once we have established the basic mechanisms which appear to me to be Output Throttling negated by Throughput Throttling.

  210. Trick says:

    Kristian 2:50pm: “…for the Earth system to regain energy balance, convection strengthens – more energy is lifted by convection from the surface to the tropopause…”

    So here Kristian reverses position, the 80+17=97 diabatic loop CAN now “strengthen” up to 81+18=99. Kristian complained before that this results in “extra” energy into the system; the (-333) going to (-337) as it must for unit 100in=100out or 239in=239out balance steady state in Fig. 5.

    How can that be Kristian? I thought you were right above to complain. Show your new numeric work out.

  211. Stephen Wilde says:

    Or rather it is mass, gravity and insolation that determine the ATE that can be achieved. Any Output Throttling from other causes being negated by Throughput Throttling.

  212. Trick says: …“throttling” implies a change to atm. energy flux density flows at equilibrium steady state.

    You have missed my point. If a particular level of “throttling” exists at steady state then it does not in any way “imply a change”.

    All it implies is that, if the measured level of throttling is deemed to be the cause of the measured level of steady state temperature, we had best concentrate on finding out what is the precise physical and mathematical relationship is between the cause and the effect.

    That’s ‘steady state thinking’. Much easier to understand and usually much more persuasive. Go to it. 🙂

    DC

  213. Trick says:

    Stephen 4:42pm: “Volume is used in the Gas Laws. I don’t need to reinvent the wheel.”

    Agreed. Good first step Stephen. Now just apply the already available gas laws to earth’s entire atm. volumetrics in Fig. 5 and show your work to gain credibility past mere assertions.

    Stephen continues: “…basic mechanisms which appear to me to be Output Throttling negated by Throughput Throttling.”

    Make sure to get your signs right Stephen – it is difficult but necessary task for experienced posters, plus (+) for net incoming flux density, outgoing net is minus (-) flux density. Both of these you mention are net outgoing flux density (-). Same signs can’t be “negated”.

  214. Trick says:

    David 5:00pm: I agree transient thermo is a beast Gibbs & Maxwell eliminated by starting papers with “let the system come to equilibrium”. Oh, and only consider “macro.”

    What happens transiently during Kristian poposed system change was pretty well described by Kristian, I’ll leave that to him. Kristian’s proposal livens the discussion though; our host expressed some satisfaction with that above.

  215. wayne says:

    Genghis February 27, 2013 at 1:45 pm:

    You stated some ‘absolutes’ above they are not correct, you completely left out the temperature of the surrounding matter. That, the temperature difference, is what determines if CO2 is a radiative cooling agent or a warming agent, not an absolute temperature, hot or cold, that is relative. CO2 cools the surface when low near the surface warming the near air toward equilibrium and cools the air when high above, always per the temperature differences. The absolute temperature only dictates the possible maximum intensity of that radiative transfer or the rate, again, depending on the temperature differences.

  216. Stephen Wilde says:

    I think Trick has lost it.

    An decrease in output is clearly a warming process and an increase in output is clearly a cooling process.

    To say that both are of the same sign is ridiculous.

  217. Trick says:

    Stephen 6:54pm: Yes! No energy lost, just conserved.

    Fine work. Got your signs right this time. A minus output and and a plus output are at least partially negated as you have just restated the Fig. 5 balance with Kristian’s proposal showing a decrease in output is as you say “clearly a warming”:

    239 SW net in – (357+41-159) LW net out = 0 LTE in balance.

    159 = 335 – 80 – 17 – 78 – (1 missing heat)

    So you then see what is happening in lower atm. once Kristian’s proposal settles to equilibrium and to conserve energy, the opposite happens in the upper atm.

    Let’s build on your clear insight here.

  218. Stephen Wilde says:

    There seems to be confusion about the term ‘throttling’.

    To my mind a throttle can either increase or decrease speed. Some here are assuming it only refers to decreasing speed.

    Some propose that CO2 throttles energy throughput in the sense of decreasing it for a warmer system.

    Some can see that convection throttles energy throughput in the sense of increasing it for a cooler system.

    Those two effects being equal and opposite.

    The cause of the ATE is thus the mass of the atmosphere constrained by gravity throttling energy throughput in the sense of decreasing it for a warmer system.

    Then after that temperature is set any further output throttling from other forcing elements is offset by throughput throttling in the sense of increasing energy throughput to negate that further output throttling.

    Kristian’s summary at 2.50 pm is good even though he started off by misunderstanding my earlier post.

    It is all very well asking for actual empirical numbers during a transition period between one thermal state and another but I doubt we could ever record them meaningfully because of the large range of potential forcing elements and the large three dimensional nature of an entire atmosphere.

    The best we can do is look at the system changes that do occur.

    The air circulation constantly changes and it is becoming increasingly apparent that latitudinal climate zone shifting is linked to apparent net cooling or net warming of the troposphere.

    Obviously the positions and sizes of the climate zones are having an effect on energy throughput.

    Similarly obviously that must be a negative system response.

    The purpose of such circulation changes can only be to keep ATE stable over time once it has been set by mass gravity and insolation.

  219. Stephen Wilde says:

    Trick.

    Please stop.

    It is you that got the signs mixed up.

    As regards upper and lower portions of the atmosphere that is no help to you as per my posts at
    1.20 pm and 1.40 pm.

  220. Trick says:

    Stephen 7:15PM, 1:20: My signs are ok Stephen, the Fig. 5 fluxes balance with these correct signs in Kristian’s porposal. Your earlier posts are no help since relying on volume in atm. physics is not helpful.

    “So the volume of the lower atmosphere becomes slightly greater …

    How much? Show your work. The computation will be exactly offset by the upper atm. volume getting slightly less. Show that work. The highest N2 molecule in orbit will have no clue all this is going on.

    1:40pm: “…no rise in surface temperature occurs at all due to volume and circulation adjustments…”

    No, Stephen can’t show conservation of Fig. 5 energy in this assertion. If so, please show your work Stephen.

    Something new comes up, let me know.

  221. gbaikie says:

    “gbaikie, wouldn’t you then maybe say that the energy density always remains the same or decreases with height even though above the stratosphere the temperature is rising? I can see that, roughly, though don’t know if it is empirically correct. Temperature is rising as the density is dropping. Don’t think I’ve ever seen that relationship on a graph or table.”

    I think it would interesting to plot the atmosphere per kg of molecules. So sea level a cubic meter
    of air is about 1.2 Kg. So for kg of air at sea level it would less than 1 cubic meter and as elevation increases there is a increasing volume of air. And having the joules of energy per kg of air per 1000 meters of elevation.
    One could also do this with fixed volume- joules per cubic meter per 1000 meters of elevation.

    Either of these types of measurement could be called energy density, though the fixed volume
    would seem more consistent or seem the more standard way to do it.

    With either if these ways- fixed volume or fixed mass- one also ask what the energy flux is in terms
    the changing amount molecule and their energy, entering and exiting the fixed volume box.
    In other words at sea level more of molecules are going to stay in the box per second, and at the stratosphere a large amount of the molecules will be exiting and entering the box per second.
    And one also say this changing nature of a box as one increases elevation has something to do with energy density.

  222. Stephen Wilde says:

    Kristian’s proposal says:

    “In other words, when radiation tries to raise the surface temperature it ‘inadvertently’ parallelly increases the temperature gradient between surface and air. The two effects cancel each other out.”

    and:

    “This is why a hypothesis of GHE (and AGW) cannot claim surface warming by ‘back radiation’, because this only affects one of the cooling mechanisms at hand. It has to find a mechanism which restricts the TOTAL cooling process of the surface, that is radiation PLUS convection”

    Which is pretty much my position of several years past.

    “relying on volume in atm. physics is not helpful.”

    It isn’t helpful in radiative physics but it is integral to the Gas Laws.

  223. Stephen Wilde says:

    Trick said:

    “The lapse profile graphs proving it with energy conservation are in the Verkley paper posted here and discussed many times”

    Verkley says that the lapse rate is independent of GHGs and I agree but only in so far as the lapse rate set by gravity is concerned.

    Ozone clearly affects the lapse rate in the stratosphere and the phase changes of water clearly alter the lapse rate in the troposphere.

    The important thing is that they cannot alter the average global net lapse rate overall so a distortion in one place has to be offset by an equal and opposite distortion elsewhere within the atmosphere.

    The equalisation process involves atmospheric expansion and contraction from a faster or slower adiabatic loop as I have explained previously.

  224. gbaikie says:

    “When a CO2 molecule absorbs a photon it becomes charged and more energetic and it may either hit another molecule and lose the energy via KE transfer or it may emit another photon. Also if another molecule with more KE hits the CO2 molecule transferring KE back to the CO2 molecule the CO2 molecule may emit a photon or transfer the KE along. Pretty basic QM stuff.”

    Wiki, Thermalisation:
    When a molecule absorbs energy, as in the technique of molecular fluorescence, the lifetime of the excited state is ~10^−12 sec. Then it rapidly loses energy to the lowest level of the lowest excited state; this is called thermalization.
    http://en.wikipedia.org/wiki/Thermalisation

    So apparently the lifetime is about 1/trillionth of second.
    And the average collision time of molecules vary with altitude.
    And at the surface, it’s somewhere around a 1/billionth of a second.

    So one could say the chance transfer is one in a thousand or the effect is
    less than 1 percent. And with higher elevation this is reduced.

  225. Genghis says:

    Wayne said, “You stated some ‘absolutes’ above they are not correct, you completely left out the temperature of the surrounding matter. That, the temperature difference, is what determines if CO2 is a radiative cooling agent or a warming agent, not an absolute temperature, hot or cold, that is relative. CO2 cools the surface when low near the surface warming the near air toward equilibrium and cools the air when high above, always per the temperature differences. The absolute temperature only dictates the possible maximum intensity of that radiative transfer or the rate, again, depending on the temperature differences.”

    Maybe Wayne : ), the equilibrium point is the absolute temperature of the parcel of air at a given density and radiation level. What I mean by radiation level is the radiation that comes from either the Ocean or the Sun. The equilibrium temperature varies with different rates of radiation. Let me provide a thought example.

    Let’s take two cold parcels of air, one that is transparent to radiation and another with C02 in it that has an equilibrium temperature of 25˚. Then we take a radiation source, and a non radiating hot plate (just conduction) and apply them to the two parcels of air.

    If we heat up the two parcels of air just with the hot plate, the pure non radiating gas will heat up faster and get much hotter than the mixed gases, simply because the mixed gases will radiate away energy. Night time conditions? Eventually the pure gas will get very hot, while the mixed gases will be slightly hotter than the hot plate.

    If we only use the pure radiation source the pure gas will not heat up. The CO2 in the mixed gases will absorb the radiation and convert it to KE that it exchanges with the non radiative gases until it reaches its equilibrium temperature.

    That also happens to be the answer to David Cosserat’s question as to whether it is output or throughput throttling. It depends on the equilibrium temperature of the atmosphere.

  226. Genghis says:

    Gbaikie says “So one could say the chance transfer is one in a thousand or the effect is
    less than 1 percent. And with higher elevation this is reduced.”

    Yes and when you consider that a molecule has millions of collisions a second thousands of events a second is significant.

  227. Stephen Wilde says, February 27, 2013 at 7:11 pm,

    There seems to be confusion about the term ‘throttling’. To my mind a throttle can either increase or decrease speed. Some here are assuming it only refers to decreasing speed.

    Some time back, Tim Folkerts suggested that ‘governor’ would be a better term than ‘throttle’. And I think I agree. But by then it was a bit too late to change terminology. So we are stuck with ‘throttle’.

    In fact, whatever term you use, the phenomenon is actually better described as ‘self-throttling’ (or ‘self-governing’). This is the reason why I keep saying we have to get away from this constant obsession with discussing change when trying to analyse why the earth balances out at a fixed temperature profile when subjected to fixed insolation, fixed gravity and fixed atmospheric mass.

    This fixed balance is not achieved by an outside agent like a fat controller in charge of a steam engine, pulling or pushing on a lever. Instead it is a consequence of the physical construction of the flow system itself. This is sometimes called parametric feedback, like a zener diode that changes its resistance when current flows through it so as to maintain a constant voltage drop across itself.

    So what we really have to concentrate on here is why the earth’s atmosphere, when subjected to a fixed 239Wm-2 energy through-flow, settles into a stable fixed temperature profile with a fixed surface temperature of 288K and a fixed lapse rate of around 6.6degC/km.

    It could be because of the physics of the convecting atmospheric column itself (what I have called its ‘effective conductivity’) is such as to create exactly the temperature conditions observed.

    Or it could be because the mechanism at the ToA that allows kinetic energy to escape to space as radiation is providing that same level of ‘effective conductivity’.

    Please let us discuss the two mechanisms in detail and come to a decision!!

    Notice that nowhere, nowhere, nowhere AT ALL in the above analysis is there anything about change. It is all FIXED. Fixed flow, fixed mass, fixed gravity, and fixed temperature profile. The only thing that we should be concentrating on in this blog trail is deciding which of the above two ‘effective conductivities’ is responsible for establishing the fixed temperature profile that we observe.

    So get with it guys, and please, please stop talking about the physics of change. It’s a lost cause. The atmosphere is too complex. It blows everybody’s mind. Nothing gets agreed and no progress is made. And above all that, it is a completely unnecessary complication. 🙂

    DC

  228. gbaikie says:

    “Gbaikie says “So one could say the chance transfer is one in a thousand or the effect is
    less than 1 percent. And with higher elevation this is reduced.”

    Yes and when you consider that a molecule has millions of collisions a second thousands of events a second is significant.”

    No it’s not significant, it’s less than 1%. So 100 watts of power would be less than 1 watt.
    Unless one assumes that each photon is going go thru this Thermalisation many times.
    So 100 times is 100%

    If this is the argument, then most of this wavelength which will absorbed will occur at short distance above the surface. Couple with very small amounts above the troposphere, where collision occur
    at much lower rate and in general is more transparent.

    Then we get to part where one get a conversion of radiate energy into kinetic molecule motion.
    Which have questions about. If photon can add to molecule velocity, how much does it add.
    So have average molecule velocity of 400 m/s, how many meters per second is it adding?
    And if say 1 m/s is added [or whatever quantity] is not as likely to cool [slow down the velocity] as to add to it?
    Other than a slight bias downward due to gravity [which is slight within the troposphere] any one
    molecule can be traveling in any vector.

    One also think of like a rocket. If a “rocket engine” emits light it adds to velocity.
    So in this way of looking at it, a molecule does not need collision to cause an increase in kinetic energy of molecule- any emission causes some amount of propulsion [and also true of absorption].
    So with solar sail if the light is bounced rather than absorbed it get more kinetic energy [moves the solar sail- reaching some fraction of light speed if given enough time [or if there is enough total photons hitting it. The problem is this is accelerating motion- a very light force in same vector over time gives high velocity- molecules colliding every nanosecond and changing their direction “have” less time].

    But still have question of how much and the random vector of the molecule.

  229. Genghis says:

    gbaikie said,

    “And if say 1 m/s is added [or whatever quantity] is not as likely to cool [slow down the velocity] as to add to it?”

    No, all the molecular collisions are completely elastic, total velocity (heat) is always increased. The only way kinetic energy can be lost is through conversion of KE to radiation. This is the key point.

    That is why GHG’s above the equilibrium point have a net cooling effect.

  230. suricat says:

    This thread is becoming farcical!

    *Genghis says: February 27, 2013 at 9:51 pm

    “Eventually the pure gas will get very hot, while the mixed gases will be slightly hotter than the hot plate.”

    This is IMPOSSIBLE! The ‘Planck Energy Level’ of the ‘Gas’ can never be greater than that of it’s ‘Heat Source’!

    */ My how this thread has grown in just a day. I just can’t keep up, so I’m not going to. I’ll just ‘throw in’ a few statements. 🙂

    ‘Fig. 5’ shows 80W/m^2 of radiant energy leaving Earth’s surface because the 80W/m^2 for ‘LH’ is without any temperature effect.

    ‘Fig. 7’ Is just WRONG and unrepresentative. ‘LH’ has disappeared and atmospheric absorption of incoming SW now comes from the surface.

    I’m not so sure I want to be involved with this thread any more. 😦

    *OP on Fig. 7.

    “Wow! Simple or what? All that complicated climate sciencey stuff is now compressed down into one elementary diagram. Of course it won’t be a diagram that will be of much interest or use to people studying the intricacies of atmospheric sciences. (I fully expect it to generate many howls of anguish, just like before.) But for our purposes here it will do just fine.”

    So, why are so many posters commenting on the subject of ‘atmospheric science’???

    This makes me pose the question. ‘What are your “purposes here” David’??? With Fig. 7 you’ve altered Earth’s thermodynamic to one that’s closer to Mars.

    */ It’ll take a lot of corrective posting before I post in this thread again.

    Ray.

  231. gbaikie says:

    David Socrates

    I don’t see how governor is better than throttle or why any of them is better than engine [or fuel].
    But anyhow, you say:

    “Notice that nowhere, nowhere, nowhere AT ALL in the above analysis is there anything about change. It is all FIXED. Fixed flow, fixed mass, fixed gravity, and fixed temperature profile. The only thing that we should be concentrating on in this blog trail is deciding which of the above two ‘effective conductivities’ is responsible for establishing the fixed temperature profile that we observe.”

    Which make think about oceans. So what controls ocean temperature?
    Or the sun shines on ocean for millions of year why isn’t ocean hotter.
    It seems the thing that control ocean is evaporation.
    Take extreme amounts of radiant energy and shine it on water and
    it’s not going warm the water by much if the water can evaporate.

    So Earth ocean have a max temperature of 30 to 40 C and land surface
    has max of 70 to 75 C.
    But the other question is what stops the entire ocean from warming up
    more than about 3 C. The ocean have had average temperature higher
    than 10 C, but not lately. The ocean a higher average temperature
    before we entered this Ice Age we have been in for tens of millions of years.

    So probably what stops average ocean temperature from reaching 10 C is
    the presence of ice caps.
    But if continue to have evaporation and continue to have ice caps is there
    with these braking mechanisms, a limit to how warm the average ocean
    can get? Can if given enough time, at more or less the present conditions,
    could average ocean warm to say 5 C.

    I am not convinced that summer time melting the arctic polar sea will
    result in warmer oceans. The only big effect which seem possible
    from doing this is increasing amount water vapor in arctic region-
    which generally translates to more snow. which might make it colder up
    there and cause less polar ice caps from melting and as consequence
    cause less cold water reaching most of the ocean [making a warmer ocean-
    so in sort of in a backwards way, bring this about.]

    Or an extreme [and impossible] example if you could thoroughly freeze the
    arctic regions, and the oceans elsewhere could warm up. Though it may not be
    impossible in glacial period, but in terms of interglacial period it fits this
    nature of being impossible.
    Or there are other means of stopping the flow of cold water from the poles.

    Though there different way to look at it. One could just ignore the average
    ocean temperature and be concerned about the surface temperature of the
    Ocean. Or if ocean depth were colder than they are now, that would slow
    down the polar cold water and it could irrelevant.
    What does it matter if ocean average temperature was 2 C rather than 3 C?
    If one had colder average ocean, one could have a higher average ocean
    surface temperature, and such warmer ocean would direct effect upon
    giving warmer weather

  232. suricat says:

    Sorry, but I just couldn’t resist this.

    *David Socrates says: February 28, 2013 at 12:13 am

    “So what we really have to concentrate on here is why the earth’s atmosphere, when subjected to a fixed 239Wm-2 energy through-flow, settles into a stable fixed temperature profile with a fixed surface temperature of 288K and a fixed lapse rate of around 6.6degC/km.”

    NO! What you’re asking is ‘how can we estimate an Earth atmospheric reaction WITHOUT an ‘Earth atmosphere’.

    Plain and simple. We can’t!!! 🙂

    */ Bye for now. 🙂

    Ray.

  233. donald penman says:

    http://en.wikipedia.org/wiki/Atmosphere_of_Venus
    A comparison between Venus and the earth could be useful here and a couple of things stand out here to me ,the core of Venus has cooled quickly and the high loss of atmosphere to space.The atmosphere of Venus has layers like the earth and what happened to the atmosphere of Venus could have been runaway convection rather than a runaway greenhouse which would have been fuelled by the evaporation of GHG.

  234. Suricat,

    I was expecting a howl of rage over my Fig. 7 and I am just surprised it has taken so long to come.

    You have entirely misunderstood the scientific virtue of holding all variables except a few constant, so that one can investigate just one small aspect at a time of a very complex phenomenon.

    Visits to this blog trail are not compulsory. 🙂

  235. gbaikie says, February 28, 2013 at 1:57 am: Which make think about oceans. So what controls ocean temperature? Or the sun shines on ocean for millions of year why isn’t ocean hotter. It seems the thing that control ocean is evaporation.

    Quite so. Evaporation it is.

    Averaged over the long term, the oceans lose heat at exactly the same rate that they gain heat from the Sun. That is why, again over the long term, they remain at the same average temperature. So, averaged over time and space, energy in = energy out; leading to energy balance; leading to fixed temperatures.

    Did you not see in my Fig. 5 above that the SURFACE is clearly marked as standing for “land+ocean”? The 80Wm-2 leaving the surface represents the latent heat of vaporisation of water (which is of course mainly from the oceans). The latent heat is carried by convection to cloud level where it is converted to ‘sensible heat’ as it precipitates as rain or snow – i.e. it warms the air around it at that level, increasing its kinetic energy (labelled KE). The air, as the diagram shows, carries on upwards and its KE is converted at the ToA to radiation that is lost to space.

    Fig. 5 clearly shows the energy balances for all forms of energy transfer into the earth and out again to space. It is because they are in balance (well, all but 1Wm-2 !) that the earth’s long term average temperature is at its observed average stable level of around 289K.

    So all your wild speculations about ice caps are unnecessary! With respect, you are trying too hard to understand all the almost impossibly complex details before you understand the ‘big picture’ – which is all to do with energy balances.

    That is why I keep banging on about focussing on the steady state situation we are presented with on earth as a result of an almost perfect balancing mechanism.

    And it is why I keep asking the much simpler question: what is the precise mechanism that causes the temperature at the earth’s surface to be enhanced by several tens of degrees C over what it would be if there were no atmosphere at all?

    (1) Is it resistance to flow of air by convection up the atmospheric column (‘Throughput Throttling’)?

    (2) Or is it a restriction at the ToA caused by the way the GHGs there convert the rising KE to radiation that is lost to space (‘Output Throttling’)?

    Please, out of respect for the purpose of this particular blog article, try to keep your thoughts directed towards that simple question. It is the only question we are asking here.

    DC

  236. gbaikie,

    On reflection, I was a bit dismissive about your ‘ice caps’ comment. It is true that the ice caps are indeed part of the earth’s overall energy balance mechanism, because ice is highly reflective and returns a proportion of the incoming Sun’s energy straight back to space.

    That is not catered for in Fig. 5 because here in Part II we are concentrating only on that proportion of the Sun’s energy that is absorbed by the atmosphere and by the surface, which is obviously less than if the ice caps (and other reflective surfaces) weren’t there!

    For the overall energy balance figures, you should take a look at Fig. 1 in Part I.

    But don’t get distracted by warmist alarmism that ‘the ice caps are melting’. Stay with the big picture. 🙂

    DC

  237. donald penman says, February 28, 2013 at 4:38 am: The atmosphere of Venus has layers like the earth and what happened to the atmosphere of Venus could have been runaway convection rather than a runaway greenhouse which would have been fuelled by the evaporation of GHG.

    donald,

    You don’t have to speculate on ‘what happened to Venus’.

    Nothing ‘happened’ to Venus.

    Venus is what it is: a planet, just like all the other planets in the solar system.

    It is in energy balance (on average over time and surface) with the energy it receives from the Sun, just like all the other planets in the solar system

    It has fixed insolation, fixed atmospheric mass, and a fixed gravitational constant, just like all the other planets in the solar system.

    Consequently, its atmospheric temperature profile is fixed, in exactly the same way as the atmospheric temperature profiles of all the other planets are fixed.

    It so happens that the Venus atmosphere contains 96.5% CO2 whereas the earth’s atmosphere contains 0.04% CO2. It is also a fact that its surface pressure is 92 times the earth’s surface pressure. Although that latter comparison may give you quite a strong clue as to what is going on, don’t let any of those statistics distract you into thinking that anything ‘runaway’ has ever happened on Venus, either due to radiative or convective effects or anything else.

    ______________________________________________

    Please now could I ask you to concentrate on the purpose of this particular blog trail – to try to answer the question: why is the temperature at the earth’s surface enhanced by several tens of degrees C over what it would be if there were no atmosphere at all?

    (1) Is it resistance to flow of air by convection up the atmospheric column (‘Throughput Throttling’)?

    (2) Or is it a restriction at the ToA caused by the way the GHGs there convert the rising KE to radiation that is then lost to space (‘Output Throttling’)?

    Thanks.

    DC

  238. Genghis says:

    *Genghis says: February 27, 2013 at 9:51 pm

    “Eventually the pure gas will get very hot, while the mixed gases will be slightly hotter than the hot plate.”

    Suricat says,

    “This is IMPOSSIBLE! The ‘Planck Energy Level’ of the ‘Gas’ can never be greater than that of it’s ‘Heat Source’!”

    That is true if the temperature of the ‘heat source’ stays constant’. If you consider though that the hot plate is simply transferring lets say 100 watts to the system then both the hot plate and the air will eventually get extremely hot.

    [Ghengis please desist from this line of discussion. It is off-topic. Thanks. DC]

  239. clivebest says:

    David asks: “Please let us discuss the two mechanisms in detail and come to a decision!!”

    Looking at each one in turn.

    Output throttling only: Lets imagine that the Earth could only cool through output throttling. For example there is little convection possible from the surface because the atmosphere has the consistency of porridge. So the surface can only cool through radiative transfer up through the porridge to the TOA where it radiates to space.

    In this case the surface temperature needs to rise to 350K. This is the extreme greenhouse effect for an output throttling world. See : Greenhouse Effect: A Scientific Analysis” (Grazing Lands) by Richard Lindzen.

    Throughput throttling only: Imagine now that the atmosphere contains no radiative gases at all. It is composed of say 100% Argon. The only radiative losses to space that can occur are now only be from the surface. The surface temperature must be 255K ( actually it will be higher than this because there are no clouds). Limited convection will still generate a lapse rate but the tropopause will be much lower.

    Both together: This is what actually occurs on Earth. Convection, evaporation and the environmental lapse rate reduces the greenhouse effect on Earth because they act somewhat like a “release valve” moving heat up more efficiently through the atmosphere to then radiate out to space. The more humid the air the less steep the lapse rate and the less effect any increases in CO2 will have on the surface temperature. However there still is a limited CO2 greenhouse effect. If you removed all the CO2 from the atmosphere then surface temperatures would fall by about 4 deg.C.

    So I think throughput throttling is the control valve which limits output throttling (radiative forcing). It is indeed the ultimate negative feedback!

    [Moderation note] Clive: found three of these comments in the spam, sorry for the delay. Dunno why they went there. WordPress glitch. Changed submission time to get it to the top of the recent comments

  240. Stephen Wilde says:

    “So I think throughput throttling is the control valve which limits output throttling (radiative forcing). It is indeed the ultimate negative feedback!”

    Agreed as stated previously.

    Mass and gravity together set the maximum possible delay in transmission of energy through the oceans and atmosphere.The diabatic loop. That sets equilibrium temperature.

    Other factors can try and alter that length of delay but are offset by an equal and opposite response in the adiabatic loop.

    The whole setup is a result of the pressure decline with height which automatically sets the rate of decline in temperature with height.

    Both absolute pressure and the rate of decline with height are determined by mass held by gravity and any available external energy source determines the height of the atmosphere across which the lapse rate slope must travel to space.

    Between surface and space within an atmosphere it is all about the Ideal Gas Law.

    Radiative physics only applies at TOA between atmosphere and space.

  241. Trick says:

    Clive 4:15pm: “In this case the surface temperature needs to rise to 350K.”

    Thanks for the link under output throttling. The paper refers to “sphisticated radiative transfer models” w/o citation. Have you been able to duplicate the To=350K work out or know a ref. that does? If the physics of output throttling sets earth’s To to 350K then it would be a good way to understand more details of the output throttling process David writes about in top post.

    Also Clive writes “throughput throttling is the control valve which limits output throttling (radiative forcing)” – seems radiative is David’s throughput not David’s output…..so I don’t get this, can you clarify?

  242. clivebest says:

    Trick,

    If you switch off convection and latent heat then all heat transfer through the atmosphere can only occur by radiation. So there needs to be an increase in radiative transfer of about 100 W/m2. This can only occur with higher surface temperatures as T^4. This heat flux generates a quasi radiative “lapse rate” as shown by the dotted line here.

    Based on these figures a Aaprofile for the 15 micron band is shown here for T=350K compared to the actual profile. You see that at the TOA the net outgoing radiation is the same but the profiles are radically different.

    “throughput throttling is the control valve which limits output throttling (radiative forcing)” – seems radiative is David’s throughput not David’s output…..so I don’t get this, can you clarify?

    All I mean here is that convection and evaporation increase the effective “coefficient of heat transfer”decrease or “throttling” if you prefer, thereby reducing the temperature gradient up to the TOA. The temperature of the TOA is defined by isolation and albedo.

    Cloud albedo may well be the Earth’s ultimate thermostat.

  243. gbaikie says:

    “David asks: “Please let us discuss the two mechanisms in detail and come to a decision!!”

    Looking at each one in turn.

    Output throttling only: Lets imagine that the Earth could only cool through output throttling. For example there is little convection possible from the surface because the atmosphere has the consistency of porridge. So the surface can only cool through radiative transfer up through the porridge to the TOA where it radiates to space.

    In this case the surface temperature needs to rise to 350K. This is the extreme greenhouse effect for an output throttling world. See : Greenhouse Effect: A Scientific Analysis” (Grazing Lands) by Richard Lindzen.

    Throughput throttling only: Imagine now that the atmosphere contains no radiative gases at all. It is composed of say 100% Argon. The only radiative losses to space that can occur are now only be from the surface. The surface temperature must be 255K ( actually it will be higher than this because there are no clouds). Limited convection will still generate a lapse rate but the tropopause will be much lower.”

    How one gets to 255 K is using ideal blackbody and altering the ideal blackbody by imagining about 1/3 of sunlight is reflected [Bond albedo]. A world with 100% Argon may not have the same Bond albedo.

    Second it’s assumes an ideal blackbody is giving the warmest average global temperature surface which is possible.

    Third, the more of any kind of gas for the atmosphere the less energy from sunlight reaches the surface- a 100 atm of Argon will allow less sunlight to reach the surface than 1 atm of Argon.

    Fourth an ideal blackbody makes a uniform global temperature- before adding atmosphere and albedo one has uniform temperature of 5.3 C- which means a polar region in 6 months of winter darkness would surface temperature of 5.3 C.

    Fifth the ideal blackbody nor any part of greenhouse model stores thermal energy, and an ocean stores vast amounts of thermal energy. And ocean stores the energy beneath it’s top surface.

    So the 255 K temperature is a “damaged” blackbody temperature and this uniform temperature rather than average temperature with higher temperature in tropics and cooler temperature in polar regions.

    So forget about ideal blackbodies and perverting them. Start with world of water and
    Argon

  244. clivebest says:

    gbaike,

    Your first point: OK lets change it so that the albedo is 1. The surface temperature will now increase from 255 K to become 279 K.

    Second point: Yes it does assume that the surface acts as a black body. I think that is reasonable since in equilibrium where else could the absorbed solar energy go except be radiated as heat.? Conduction and convection will heat the atmosphere, but without radiative gases the energy is not going anywhere because a vacuum is a perfect insulator. Some energy will be lost as molecules at the top of the atmosphere reach the escape velocity but this is tiny.

    Third point: There will be some absorption of solar energy by a thick argon atmosphere by ionisation. But again I don’t think this is a key issue.

    Fourth and Fifth: I agree that in the real world differential heating and oceans change the dynamics. Water alone produces most of the so-called greenhouse effect on Earth. However with respect that is not the point . The post asks us to decide between “throughput” and “output” throttling.

    So really I think you are really agreeing with me that the answer to this post is that you need both. They work together to maximise heat loss and increase entropy.

  245. donald penman says:

    David socrates
    I don’t agree that anything is fixed both Venus and the Earth are changing over time there is no stability of temperature over the life-span of the Earth since it cooled from a molten ball of rock.You define the planet Earth as stable but there is no law of planetary formation which requires a planet to have a thermostat, if the earths temperature had varied ten times more than it appears to have looking at the geological records you would still call this stable,stability is just something you wish for .There is nothing special about the relationship between “throughput throttling “ and “outputt throttling”at this moment in time,the history of the Earth is important because a few billion years ago the composition of the atmosphere was not the same as it is today.What “happened” to Venus is important to me and I will continue to think that something “happened” to Venus ,the important question is what is going to “happen” to Venus and the Earth in the future. With regard to the question then both mechanisms are quite weak ,I will only be convinced that they give a true picture of what is happening on the earth if there is evidence to support the mechanisms until then they are just theoretical.

  246. Trick says:

    Clive 6:34pm – Yes, I can see the results. What I need is the ref. calculations for the curves.

    The issue for me is that in David’s top post Fig. 5 being at equilibrium, the total energy “throughput” is constant; so in the real earth physics both “output” and “throughput” exist in nature for balance at David’s To=287 at 0km Po=1013.25mb. In the curves you link at 6:34pm, it is obvious the total energy is NOT held constant. I’m interested why is that and what does it mean about model assumptions? Verkley paper is very careful to hold energy (really, gas enthalpy) constant in their column T v. P profiles.

    It might be that the model assumptions being analyzed for To=350K are different than David’s so the conclusions would be different; in part meaning for David’s case pure “output throttling” To at Po would be different than 350K.

  247. clivebest says:

    Trick,

    Everything is basically a heat transfer problem from the surface to space. The earth can only cool through radiation. Some wavelengths are opaque to IR photons near the surface. Radiation is then in thermal equilibrium with the surrounding air molecules. Photons travel only short distances before being absorbed. As the air thins out with height so the mean free path for photons in these wavelengths increases. For each wavelength there is an “effective emission height” where the mean free path upwards becomes greater than the top of the atmosphere ( i.e. outer space). Photons then escape and cool the atmosphere. When averaged over all wavelengths the net energy loss by radiation must equal the net energy input from the sun.

    The effective emission height for wavelengths in the 15 micron band depend on the amount of CO2 in the atmosphere. If this increases then the effective emission height also increases. The key player in the Earth’s heat transfer is the lapse rate and the wavelength averaged effective emission height . The latter essentially defines the tropopause which is where convection stops. It stops there because radiative heat loss dominates. What will actually happen when CO2 increases is more complex than this because no-one really knows how water vapour and clouds will react. I don’t think the IPCC know either.

  248. Trick says:

    Clive 10:21pm: “When averaged over all wavelengths the net energy loss by radiation must equal the net energy input from the sun.”

    Yes, as David shows in Fig. 5 above and Verkley paper is very careful to control for that balance. However, the two figures you show 6:34pm do not have this balance i.e. do not have same total energy in each of two T profiles – why is that? Look carefully; in the Lindzen curves delta Ts is shown higher from surface up to end of curve and the other one shows the red curve higher W/m^2 from 0km to ~15.5km.

    What I would expect to see as in Verkley paper is if the lower atm. is shown to cool slower by the “throttling” process (either output or throughput) then that slowed heat flow is “throttled” back from higher up (above about 5km or 600hPa) and the upper atm. would then be shown compensating in T or W/m^2 with less energy available.

    I’ll search on my own, thought you could save some work & time having a ready ref. or workout available.

  249. gbaikie says:

    “gbaikie,

    Your first point: OK lets change it so that the albedo is 1. The surface temperature will now increase from 255 K to become 279 K.

    Second point: Yes it does assume that the surface acts as a black body. I think that is reasonable since in equilibrium where else could the absorbed solar energy go except be radiated as heat.?”

    Where else? It can be conducted further beneath the surface when it’s receiving the energy of sunlight and more slowly be conducted back to the surface to be then be radiated at the surface.

    So a sidewalk [and solid rock] during daylight warms to say 70 C, 2″ beneath the surface it could be say 50 C and 4″ it’s 30 C. Sun goes down, and sidewalk returns to near air temperature of say 30 C, which lower further as night time continues. The 2″ and 4″ below the surface do not have as great heat difference as during daylight and therefore conduct heat at a slower rate. Sidewalk is storing heat during nite.
    Or one can say it’s cooling more slowly [something greenhouse gases are suppose to do].

    With oceans one has larger delay of heat stored during nite. Little sunlight energy is *conducted* from surface to lower depth, BUT the energy of sunlight during daylight *passes through the transparent surface and though a very part of the energy of sunlight goes as much as 100 meters below the surface, a much larger amount reach 10 to 20 meters below the surface [red light is absorbed by time it which
    reaches 15 meters, with orange, yellow going further, with blue reaching the furthest depth.
    Compare to a concrete sidewalk, as of the sunlight’s energy reaching 10 meter under water and is “transfering” sunlight energy faster below the surface as compared thru 10 meters of concrete.
    And for this reason Water is “better” than blackbody, energy goes in quick and get back to surface at slower rate [once at surface it radiates].
    Or an ideal blackbody is 2 dimensional, water as blackbody is 3 dimensional.

    “Third point: There will be some absorption of solar energy by a thick argon atmosphere by ionisation. But again I don’t think this is a key issue.”

    I agree. Or it’s insignificant if it does because it’s a small warming effect. But I also think the is true in regards to all gases, not just argon. More significant is with greater atmosphere one is having less sunlight reach some surface to warm.

    “Fourth and Fifth: I agree that in the real world differential heating and oceans change the dynamics. Water alone produces most of the so-called greenhouse effect on Earth. However with respect that is not the point . The post asks us to decide between “throughput” and “output” throttling. ”

    Which I lean towards “throughput”.
    But I don’t split the difference and say it 1/2 “throughput” and 1/2 “output” throttling.
    I am not completely on board with the “throughput” side, because mechanism described for atmosphere isn’t applicable. Earth atmosphere can rapidly transfer vast amount of heat to stratosphere- watch a video of nuclear explosion. Whereas with Venus, a surface nuclear explosion would be not be as similar as with on the surface of Earth [and it has little to do with different temperature of two atmospheres].
    But will grant their may be some “output” throttling, I tend to think it’s fairly insignificant- or to say more directly, I don’t accept greenhouse gases add 33 C to average global temperature.
    If the claim was 5 to 10 C, I say it’s possible. But most of this is water vapor and with water vapor also has the heat latency of water vapor- so if one is limiting it to radiant effects only, I tend to think less than +5 C. And most this uncertainty- it could be it’s cooling by 1 C or something.
    Or it could be a region of the world [or circumstances] have stronger effects.

  250. Tim Folkerts says:

    Well said Clive.

    It is pointless to talk about convection without radiation, or radiation without convection.
    * Convection fixes the lapse rate (give or take a little bit due to water condensation).
    * The effective radiation height controls the emissions to space (and is one of the least understood but most important ideas in earth’s energy balance).

  251. clivebest says, February 28, 2013 at 4:15 pm

    Clive,

    First of all thank you very much for responding to my plea to get back on topic. This blog trail was wandering far and wide and getting nowhere!

    On output throttling only I kind of love the idea of an atmosphere consisting of porridge so that convection cannot take place. 🙂 Unfortunately that won’t work as you intend because you would simply be swapping the relatively high (but not infinite) ‘effective conductivity’ of convection for the much lower real conductivity of porridge, resulting in an inevitably higher temperature differential up the atmospheric column, just the opposite of what you intended. Also, I am not sure you could get much radiation transfer through porridge, so you are snookered either way.

    Also your throughput throttling suggestion would not work as stated without any radiative gases at the ToA to release the rising heat to space.

    Your ‘both together’ option works for me but I personally still don’t see any role at all for greenhouse gases in the bulk of the atmosphere. Also – and this is hopefully just a minor terminological issue – output throttling is not radiative forcing (at least not as the IPCC define it!) more like radiative transformation perhaps?

    It seems to be one of the paradoxes of the controversy that raditive gases are essential energy transformation agents both for converting (that part of) the incoming radiation from the Sun that is absorbed directly by the atmosphere to KE, and for converting the KE at the ToA to radiation that is output to space, yet they do not appear to have any significant role in moving energy up the atmospheric column (apart of course from that which passes up through the atmospheric window).

    Thanks again for kicking this off in the right direction.

    DC

  252. Kristian says:

    Gotta love the way T. Folkerts comes waltzing back into the discussion as if the 150 comments following his last baseless assertion of emission height ruling surface temperature via the lapse rate were never made, leapfrogging the countering arguments and goes right back to bold-faced assertion.

    But I reiterate what I told you last time, Tim: You turn it all completely on its head. The surface temperature (set by insolation, atmospheric mass/density and gravity) controls the temperature profile all the way up to the tropopause through the lapse rate. Not the other way around. The lapse rate in no way controls surface temperature. Neither does the thermal radiation of the atmosphere, which is simply a function of that set temperature profile.

    Thermal radiation rules in the stratosphere (above the convection top). In the troposphere, convection reigns supreme, delivering heat from surface to TOA. In the troposphere, thermal radiation is just there.

  253. Stephen Wilde says, February 28, 2013 at 5:08 pm

    Stephen,

    That is a very clear and succinct statement of the position I support and is close to Clive’s third suggestion.

    However what we need now is some definitive quantitative proof.

  254. clivebest says, February 28, 2013 at 10:21 pm

    Clive,

    Thanks again, This is all very good succinct stuff and we are now focussing down onto the big issue that I have wanted to bring out.

    Tim Folkerts alerted us all a long time ago to the output throttling rationale. What we need to see now is some quantitative evidence of how strong, and therefore how significant, the output throttling mechanism is in practice.

    At one extreme is the idea (that I incline towards) that the effect is slight enough that we can consider for all practical purposes that the transformation of KE to radiation escaping to space at the ToA is an ‘open drain’. At the other extreme there are those who say output throttling is the major temperature-controlling mechanism and that convection is, in practical terms, an ‘open passageway’.

    We do need to get a quantitative handle on this if we are to make any sort of sensible judgement between the two extremes.

  255. Stephen Wilde says:

    Since 3 of us are in broad agreement I’ll repeat that 5.08 comment here for ease of reference:

    “So I think throughput throttling is the control valve which limits output throttling (radiative forcing). It is indeed the ultimate negative feedback!”

    Agreed as stated previously.

    Mass and gravity together set the maximum possible delay in transmission of energy through the oceans and atmosphere.The diabatic loop. That sets equilibrium temperature.

    Other factors can try and alter that length of delay but are offset by an equal and opposite response in the adiabatic loop.

    The whole setup is a result of the pressure decline with height which automatically sets the rate of decline in temperature with height.

    Both absolute pressure and the rate of decline with height are determined by mass held by gravity and any available external energy source determines the height of the atmosphere across which the lapse rate slope must travel to space.

    Between surface and space within an atmosphere it is all about the Ideal Gas Law.

    Radiative physics only applies at TOA between atmosphere and space”

    So, what can we do about definitive quantitative proof ?

    All I have is observations of real world atmospheric behaviour but the relevant parameters have never been measured.

    We need to have a much clearer record of how the net behaviour of the jets and climate zones varies over time plus a record of the constant hight changes in each atmospheric layer.

    That said we do have the Ideal Gas Laws and the general laws of physics in conjunction with observations with which my hypotheses do seem to comply better in my view than the purely radiative scenario.

  256. gbaikie says, March 1, 2013 at 12:09 am

    Where else? It can be conducted further beneath the surface when it’s receiving the energy of sunlight and more slowly be conducted back to the surface to be then be radiated at the surface.

    As I have emphasised many, many times, we are studying here a steady state model, not one where changes of the type you envisage are taking place. So please desist!

    “Third point: There will be some absorption of solar energy by a thick argon atmosphere by ionisation. But again I don’t think this is a key issue.” I agree. Or it’s insignificant if it does because it’s a small warming effect. But I also think the is true in regards to all gases, not just argon. More significant is with greater atmosphere one is having less sunlight reach some surface to warm.

    If you now agree argon does not absorb sunlight significantly why did you originally assert that it did? Ditto for other non-GHG gases which you now introduce as an additional diversion for which exactly the same rationale is appropriate? This is all pure sophistry and wastes everybody’s time. Please desist!

    DC

  257. Tim Folkerts says, March 1, 2013 at 12:40 am

    Tim,

    Nice to see you back. I imagined you were watching in the wings wondering if we would ever get back on track! Well here we are and here is Clive putting in some good points. Now what we need is some fleshing out of the proposed output throttling physics in quantitative terms so we can make a better judgement about how significant it is compared with throughput throttling.

    Since this new angle on the warmist creed is relatively unknown to most people (if you Google “global warming” all you get is the usual guff about radiation causing throughput throttling), could you for a start give us some digestible references on the phenomenon? Thanks!

  258. Kristian says, March 1, 2013 at 8:43 am: Gotta love the way T. Folkerts comes waltzing back into the discussion as if the 150 comments following his last baseless assertion of emission height ruling surface temperature via the lapse rate were never made, leapfrogging the countering arguments and goes right back to bold-faced assertion.

    Kristian,

    I think that is a bit unfair. I have some considerable sympathy with Tim withdrawing if it was because of all the non-steady-state and other considerably off-topic wanderings that have occurred. These got in the way and I think made most of us lose focus.

    So let’s just see what Tim now has to say now. As you will see above, I have asked him for a quantitative rationale and for references.

    I do agree that ‘argument by assertion’ is NOT what we want here.

  259. clivebest says:

    David writes:

    “Your ‘both together’ option works for me but I personally still don’t see any role at all for greenhouse gases in the bulk of the atmosphere.”

    In fact you are about right. There is very little role for CO2 in the bulk of the atmosphere. You could remove all the CO2 in the first 5 km and it would have very little effect on surface temperatures. 90% of emissions to space occur in the upper troposphere and stratosphere.

    Water is different because it determines the lapse rate, generates clouds AND radiates to space.

  260. donald penman says, February 28, 2013 at 7:14 pm

    donald,

    As you will by now realise, the issue you raise is strictly off-topic for this thread. Nevertheless I find your reply perfectly resonable and rational, so it deserves a brief response.

    It is all a question of timescales. On this thread we are looking for the physical mechanism that has caused the earth’s surface temperature to be maintained at a remarkably steady level (within a degree or so) over hundreds of years. You are quite correct that the paleological record shows that larger changes occurred over millions of years. If that is your speciality and interest, fine. Just not here on this thread, please, where we are trying to conduct a very focussed discussion on a much more limited ‘steady-state’ model. Maybe we won’t succeed and your views will prevail. But that is what we are doing here.

    All the best. 🙂

  261. clivebest says, March 1, 2013 at 10:12 am: Water is different because it determines the lapse rate, generates clouds AND radiates to space.

    I don’t want to split hairs but ‘determines the lapse rate’? How about ‘influences’?

    Without water 10K/km. With water 6.5K/km (US Standard Atmosphere).

  262. clivebest says:

    Trick writes: ” Look carefully; in the Lindzen curves delta Ts is shown higher from surface up to end of curve and the other one shows the red curve higher W/m^2 from 0km to ~15.5km.”

    Most textbooks (for example Houghton’s) show the lapse rate as a straight line. So an increase in emission height translates to a fixed DT change throughout the atmosphere. Lindzen though is correct to use the moist lapse rate and that changes rapidly with temperature as can be seen on a skewT graph. A reduction in the lapse rate is a negative feedback.

    The radiative profiles are my calculations based on my “mickey mouse” radiative transfer program . The red curve is for the CO2 component of 100% radiative heating of the atmosphere (no convection).

    I will now read properly Verkley’s paper.

  263. clivebest says, March 1, 2013 at 10:32 am says: I will now read properly Verkley’s paper.

    Googling “verkley atmosphere” provides references to 22 separate papers by Wim Verkley. A link to the correct one would be more than helpful.

    Or, actually, probably not for most of us. From past bitter experience with Trick and Verkley, I warn other innocent readers here that Trick and Clive are now likely to enter a long infinite tunnel of incomprehensibility.

    If that happens again here, it will be strictly but fairly moderated, particularly to ensure that Trick (who has been remarkably cogent recently) does not descend once again into ‘mathematikspeekenschriftbahkengerfunkt’ 🙂

  264. Stephen Wilde says:

    That straight line lapse rate is very misleading whoever uses it.

    It would be fair enough for an average slope from surface to top of atmosphere and if it only represents the theoretical lapse rate set by gravity.

    The trouble then is that no one actually knows what the ‘pure’ lapse rate set by gravity actually is because even dry air doesn’t match it exactly so it never is achieved at any given level within an atmosphere.

    Within an atmosphere ALL observed lapse rates are merely environmental or local lapse rates which vary all the time at every level and location. It even reverses in the stratosphere because of ozone directly absorbibg solar shortwave and in the thermosphere where direct soilar impacts dominate over thermal effects from below.

    The only reason the Standard Atmosphere works is because of the power of water vapour overwhelming everything else within the troposphere so that the rate of decline with height is relatively stable within that layer but it can still vary from convective updrafts and downdrafts hence the concern at airports about microbursts from storms.

    The fact is that lots of factors alter real world lapse rates all the time so unless we get lots more data we cannot prove anything.

    That lapse rate data would be implicit in my reference to atmospheric heights above.

    AGW theory appears to rely on the lapse rates staying the same when compositional changes occur within the atmosphere which is why they extrapolate the lapse rate back to the surface from a so called effective radiating level (ERL).

    If lapse rates vary with atmospheric heights via expansion and contraction then there is no need to expect a surface temperature increase.

    Instead the slope of the lapse rate changes locally with an opposite slope change elsewhere in the atmosphere vertically or horizontally in order to keep the average slope as set by gravity.

    That is what the circulation changes are all about with consequent climate zone and jet stream shifting.

    The ERL is an incorrect concept in my view. The correct view is that when an atmosphere expands or contracts the temperature at which it radiates stays the same but the heights rise or fall.

    The idea of radiation from a cooler location causing warming at the surface is therefore wrong in reality.

    The changes that have been observed and which led to the AGW scare were simply part of the natural variations about the mean caused by sun and oceans. Those variations can be on millennial time scales as per MWP to LIA to date.

    Ultimately determined by the sun but modulated through the thermohaline circulation.

  265. Stephen Wilde says, March 1, 2013 at 11:25 am

    Stephen,

    Your points about environmental (local) lapse rates are well articulated. People talking about different lapse rates and other local phenomena in different atmospheric conditions is what led us astray recently.

    That is why, for the purposes of the model we are discussing here, I would stick resolutely to the US Standard Atmosphere lapse rate of 6.5K/km.

    Insisting on that then throws the onus on to those who want to talk about the lapse rate they experienced in a sandstorm in Timbuktu in 1995 (or whatever) into the position of having to explain why their particular local observation is so important to the general thrust of our discussion. This is a much better position to be in than having our anxiety levels raised by yet another apparent complexity in this endless climate game. 🙂

  266. Trick says:

    David 11:11am: “A link to the correct (Verkley) one would be more than helpful.”

    Just type “Verkley” into tallbloke site search box above. The link starting with “journals”.

    11:49am: “I would stick resolutely to the US Standard Atmosphere lapse rate of 6.5K/km.”

    Suggested the ground rule for Fig. 5 to show temperatures at surface & at height consistent with this standard chart, so even David is not so resolute.

    The Poisson lapse rate calculation in Verkley paper derivation results in needing only atm. well mixed Cp, R, To and P(z) to calculate Fig. 5 T(p) lapse within ~10% of US Standard which also includes aerosols, etc. No term needed for atm. expansion and contraction.

  267. clivebest says:

    David writes : We do need to get a quantitative handle on this if we are to make any sort of sensible judgement between the two extremes.

    Here goes (see diagram here):

    1. Direct radiative cooling from the surface. The IR window is 40 watts/m2. Let’s also treat cloud tops as being part of the Earth’s surface, because they also radiate directly to space through the IR window. They are equivalent to a snow covered plateau – like Tibet. We just need to correct for the average height of cloud tops. This adds a further 50 watts/m2
    Direct Radiation = 90 watts/m2

    2. Radiation from the Atmosphere. This is thermal radiation escaping to space through radiative gases at wavelength dependent heights.
    Atmospheric radiation = 149 watts/m2

    3. Thermal energy in the atmosphere 2/3 of the KE in the atmosphere originates from convection/latent heat and 1/3 of the KE originates from radiative transfer of GHGs.
    Convection/Latent Heat = 100 watts/m2
    GHGs = 50 watts/m2

    If we believe Miskolczi this factor of 1/3 is no coincidence and will remain constant.

    So Throughput throttling = 2*Output throttling in the atmosphere.

  268. Trick says, March 1, 2013 at 1:19 pm

    1. Thanks very much. For those lazy enough to just want a link to the Verkley paper, here it is.

    2. Re. my Fig.5, it does not show temperatures at all. This was an omission on my part which I will correct. But Fig.7 and also Fig.1 (in Part I) do both show temperatures consistent with a lapse rate of 6.5K/km. So I am perfectly resolute on this matter!

    3. I did scan through the Verkley paper just now to re-familiarise myself from long ago. Just as my heart was sinking I came across the following:

    The profile agrees almost perfectly with the tropospheric part of the Standard Atmosphere.”

    Yessssss…! Then I stopped reading. 🙂

    Joking aside, Verkley and Gerkema’s theoretically derived figure for the tropospheric lapse rate is remarkably close to the Standard Atmosphere figure, and therefore must stand as a very interesting piece of work. They do say, however, that one of the constraints they chose (potential temperature) “still lacks a solid physical basis”. So let’s put Verkley aside as an interesting piece of corroborative work, and get on with our search for physically meaningful explanations.

  269. Stephen Wilde says:

    “one of the constraints they chose (potential temperature) “still lacks a solid physical basis” ”

    Verkley identifies a lapse rate profile in the troposphere remarkably close to that of the Standard Atmosphere which is as it is due to the thermal effects of the phase changes of water.

    That lapse rate differs from the lapse rate set by gravity which is closer to the Dry Adiabatic Lapse Rate which is near 10C per km.

    It is long established science that the temperature decline with height is caused by the pressure decline with height which is a function of mass and gravity.

    What other physical basis is needed ?

  270. Stephen Wilde says:

    Verkley says this:

    “Of course, the actual atmosphere is subject to processes like convective mixing. They prevent the atmosphere from ever coming close to thermodynamic equilibrium, that is, the ultimate state of maximal entropy”

    Which implies that he thinks that convection and other processes take the system AWAY from thermodynamic equilibrium.

    My view is that convection RETURNS the system to thermodynamic equilibrium.

    His view is impossible because there is always convection so if it were to have the effect of taking the atmosphere away from equilibrium then there would be a permanent imbalance at top of atmosphere.

    He has it the wrong way round just as does the whole of established climate science.

    They see CO2 as a disruptive force along with the extra evaporation and convection that it produces. Hence their positive feedback scenario from higher humidity.

    Instead if CO2 causes any extra convection that additional convection negates or offsets the thermal effects of CO2 (if any).

    How could they ever have formed the view that convection is other than a negative system feedback ?

  271. Trick says:

    David 2:26pm: “..and get on with our search for physically meaningful explanations.”

    …sure, to put the potential temperature constraint on a solid physical basis.

    You are still a bit short of resolute using the approx. 6.5K/km though, the exact US Standard atm. numbers to apply to Fig. 5 resolutely is as published here, use geometric (click & rotate clockwise) start page 53:

    Click to access 19770009539_1977009539.pdf

    NB: The problem with putting the relevant Verkley paper link in a post is then later searching for that exact post. Can always find it quick using the search box.

  272. clivebest says, March 1, 2013 at 2:24 pm

    Clive,

    Thanks for your contribution. But you are not quite playing to the rules here which use the Trenberth flow figures throught Parts I and II. I appreciate that you may not feel they are optimal but we do need to maintain consistency. Otherwise we are simply going to confuse everybody.

    So could you re-cast your points in terms of my existing diagrams?

    Thanks.

    DC

  273. Stephen Wilde says, March 1, 2013 at 2:43 pm: It is long established science that the temperature decline with height is caused by the pressure decline with height which is a function of mass and gravity. What other physical basis is needed ?

    Isn’t atmospheric composition the extra factor? Without water the lapse rate would be the dry adiabatic rate of 9.8K/km (Cp/g), would it not? With water vapour, it reduces in practice to the Standard Atmosphere 6.5K/km.

  274. Trick says:

    Stephen 2:56pm: “My view is that convection RETURNS the system to thermodynamic equilibrium. His view is impossible because there is always convection so if it were to have the effect of taking the atmosphere away from equilibrium then there would be a permanent imbalance at top of atmosphere. He has it the wrong way round just as does the whole of established climate science.”

    Stephen – Your view on Fig. 5 is unfortunately not ever supported by you providing numerics or proper physics. What the paper means here in context for thermo. equilibrium is the state of max. entropy achieved in David’s unforced Fig. 5 column. Yes, the paper IS correct Stephen, the real atm. never attains that point b/c atm. entropy is continuously forced down and away from thermodynamic equilibrium in David’s Fig. 5 forcing.

    Convection does NOT return the atm. to thermodynamic equilibrium. Convection helps for thermal equilibrium.

    I know you don’t grok the math basis of max. entropy Stephen yet Verkley&Gerkema do, there is no permanent unbalance to be found as you write. That is an issue b/c you make incorrect & non-physical conclusions for David’s Fig. 5 forced & unforced due that circumstance. You really need to make the effort (like others work at it) to be able to provide numerics (really, grok the math/numerics) in criticizing the science in order to have credibility, just like everyone else.

    Harsh circumstance I understand; the math is fairly simple but not easy.

  275. Stephen Wilde says, March 1, 2013 at 2:56 pm: My view is that convection RETURNS the system to thermodynamic equilibrium

    My view is that there is no RETURNing involved. One is simply dealing with two completely separate cases:

    (1) atmosphere with convection, causing fixed equilibrium temperature A

    (2) atmosphere (magically) without convection causing fixed equilibrium temperature B.

    Yes, the process of changing from one state to the other would be a very uncomfortable experience indeed but, once the change was completed, you would have just another stable equilibrium state.

    I think I shall have to create a ‘fast key’ for the word fixed 🙂

  276. Trick says:

    David 3:12pm: “Isn’t atmospheric composition the extra factor?”

    Yes , atm. composition matters.

    “Without water the lapse rate would be the dry adiabatic rate of 9.8K/km (Cp/g), would it not?”

    This g/Cp really, is an approximation that is not as close as Poisson lapse. So not entirely, the “dry” part means only an assumption of not enough water vapor to cause condensing when the parcel is raised adiabatically, meaning if enough water vapor present to condense then latent heat needs to be part of the math.

    “With water vapour, it reduces in practice to the Standard Atmosphere 6.5K/km.”

    Partly, because the real atm. has enough water vapor to cause the condensing.

  277. Stephen Wilde says:

    “Isn’t atmospheric composition the extra factor? ”

    Yes indeed.

    I thought the problem was the base lapse rate set by gravity but I see that it is the deviations from it that are causing confusion.

    Composition changes do distort the real world lapse rates away from the pure lapse rate set by gravity.

    The circulation then changes to negate the effect over all so that globally on average the basic lapse rate set by gravity is still met. If it were not to be met then long term the atmosphere could not be retained.

    The Standard Atmosphere is based on the distorted lapse rate caused by the presence of water vapour in the Troposphere and the Stratosphere has a reversed lapse rate caused by the effects of solar shortwave on ozone.

    Both are compositional features and the amount of water vapour or the speed of its cycling is down to the rate of energy release by the oceans whereas the amount of ozone is affected by the mix of solar particles and wavelengths.

    So the vast majority of climate zone shifting is caused by sun and oceans affecting atmospheric composition which alters lapse rates and volumes (as per the Gas Laws) and therefore circulation.

    The circulation change then alters the throughput of energy to cancel the effect on throughput of the initial distortion.

    If CO2 has its own thermal effect then it will be similarly countered by a circulation change but with CO2 being only 0.004% of the atmosphere we could never see its circulatory effects amongst the vastly greater such effects from sun and oceans.

    Isn’t that a physically meaningful explanation ?

  278. Stephen Wilde says:

    David said:

    “My view is that there is no RETURNing involved. One is simply dealing with two completely separate cases:

    (1) atmosphere with convection, causing fixed equilibrium temperature A

    (2) atmosphere (magically) without convection causing fixed equilibrium temperature B.”

    In your model maybe.

    In the real world there is constant shifting between more convection and less convection in order to keep the system stable.

    Whatever the combined effect from multiple forcing elements at any given time the amount and speed of convection always pulls the system back towards equilibrium.

    It often overshoots one way or the other due to the complexity of the combined forcing elements but that just gives us oscillations either side of the mean on millennial time scales (MWP to LIA to date).

  279. clivebest says:

    David,

    They are actually Trenberth’s figures. The only difference is that I would assign 50W/m2 to cloud tops whereas he seemingly assigns 30 W/m2. This 30 W/m2 is a mystery to me.

    I am only talking just about the 239 W/m2 “emitted by Atmosphere”.
    Forget all the other stuff like “Back Radiation”

    He has 40 W/m2 IR-window (same as me)
    30 W/m2 Cloud tops (this figure is a mystery and not well explained in his paper)
    169 W/m2 from TOA

    My figures are
    40 ( =0.38*99) Note : 99W/m2 is what Trenberth calculates for clear skies
    50 (= 0.62*80) 80 is the reduced window flux at 273 K ( average temp of cloud tops)
    149 “thermal” emissions from TOA

    This gives the 2:1 ratio .

    Trenberth’s figures would give 57:43

  280. Stephen Wilde says:

    “(1) atmosphere with convection, causing fixed equilibrium temperature A

    (2) atmosphere (magically) without convection causing fixed equilibrium temperature B.””

    That suggests different equilibrium temperatures with and without convection which then implies that the amount of convection is always fixed and that convection makes a difference to the equilibrium temperature set by mass and gravity at a given level of insolation.

    I think the problem you have with that is that scenario (2) is actually that of a solid rather than a gas so then yes the equilibrium temperature would be different.

    A gas will always have convection, will always comply with the gas laws and will always have a fixed equilibrium temperature set by mass gravity and insolation and any divergences from that temperature caused by composition changes will always be negated by circulation changes.

    That is what gases do. And liquids such as oceans too, but not solids.

  281. Trick says:

    Stephen3:35pm: “ Isn’t that a physically meaningful explanation ?”

    You haven’t shown numerically that your conjecture conserves energy in David’s Fig. 5. If it does, then show how it does numerically using Fig. 5 flux density at equilibrium. I’ve shown your conjecture of a “…thermal effect then it will be similarly countered by a circulation change…” necessarily relies on energy being created in Fig. 5 (to increase adiabatic loop size; no change in diabatic loop 239in=239out or unit 100in=100out).

  282. Stephen Wilde says:

    An interesting thought about David’s scenarios with and without convection.

    Without convection, for a solid, composition matters greatly as regards equilibrium temperature.

    For a liquid or a very dense atmosphere composition matters less due to the scope for limited convection.

    For a thin gas such as our atmosphere with low viscosity and able to convect freely composition matters very little.

    Basically the more viscous the medium the more composition matters because convection is restricted by viscosity (density).

    With our atmosphere’s ability to convect further enhanced by the fact that water vapour is lighter than air we have even less reason to think that composition variations have a significant effect on our equilibrium temperature.

    The Ideal Gas Law is based on the proposition that the temperature of gases in space is set only by mass and gravity even without insolation.

    Any convection inevitably results in a circulation and changes in atmospheric heights (volume) so the fact is that in an atmosphere it is the circulation that must be the primary means of regulating energy throughput in accordance with the Gas Laws so as to maintain TOA radiative balance.

    Basically the thinner an atmosphere and the more freely it can convect the less the equilibrium temperature will rise as a result of a particular variation in composition.

    On that basis I’m inclined to now accept that there might be some rise in equilibrium temperature from compositional changes that lead to more convection but for a gas as thin as our atmosphere assisted by a water cycle it would be infinitesimal. David’s ‘open drain’ concept is apt.

    Mars is a good example in that the atmosphere is so thin that a small amount of convection is well able to dissipate any significant thermal effect from a 90% CO2 atmosphere.

    On Venus the thickness of the atmosphere limits the cooling effect of convection so composition becomes proportionately more important.

    I am also doubtful that the net thermal effect of CO2 would be a rise in temperature anyway due to its ability to radiate out better than non GHGs.

    I suspect that the net effect of CO2 is probably zero or close to it which is why atmospheric thickness sets the temperatures of Mars and Venus at their respective distances from the sun.

    In any event the S-B equation is irrelevant to the temperature at any point within an atmosphere.

    The relationship between the speed of convection and the viscosity (density) of an atmosphere therefore determines the extent to which a compositional change can affect equilibrium temperature.

    Perhaps someone could crunch some numbers on that basis ?

    Note that viscosity is a function of mass so the entire mass of the atmosphere is involved which relegates the radiative effects of CO2 to insignificance.

  283. Stephen Wilde says:

    I think my concession of a change in equilibrium temperature deals with Trick’s continuing objections to my hypotheses.

    It is just that in our thin atmosphere assisted by water vapour and from 0.004% of the atmosphere it might as well be zero as regards any effect from CO2.

    And of course the net thermal effect of CO2 might be zero anyway.

  284. Stephen Wilde says:

    “The relationship between the speed of convection and the viscosity (density) of an atmosphere therefore determines the extent to which a compositional change can affect equilibrium temperature.”

    I think that is it.

    A denser more massive atmosphere reduces the thermal effectiveness of convection for a greater effect on equilibrium temperature from a given change in composition.

    A thinner less massive atmosphere increases the thermal effectiveness of convection for a smaller effect on equilibrium temperature from a given change in composition.

    Hence the relevance of n in PV= nRT

    which reaffirms my earlier articles to the extent that reduced n per unit of V results in lower T than would otherwise have resulted from altering T via means other than n(mass) or P(gravity).

    The thermal effect of changing radiative characteristics in our particular atmosphere by increasing CO2 is almost completely eliminated by the consequent increase in V and reduction of n per unit of V.

    That relationship has been implicit in my earlier work all along but not so clearly stated.

  285. Stephen Wilde says:

    Furthermore it is at least arguable (subject to empirical data) that the additional boost to convection from the surface of a planet with more than a certain amount of water cover could remove the need for any rise in equilibrium temperature at all when composition changes occur in the atmosphere.

  286. clivebest says, March 1, 2013 at 3:53 pm: David, They are actually Trenberth’s figures. The only difference is that I would assign 50W/m2 to cloud tops whereas he seemingly assigns 30 W/m2. This 30 W/m2 is a mystery to me. Clive

    Clive,

    Has it occurred to you that it might be just as great a mystery to us why you have chosen 50 rather than 30? 🙂

    Seriously, though, I do see that clouds are under-represented in my diagrams and I am open to the idea of changing the diagram in the future. But, right or wrong, for now we are working with Trenberth’s figures. As I have often said when this kind of discussion has come up, please send me some references and justifications and then in the future I can consider altering it.

    What would be interesting for now is for you to explain why a 2:1 ratio is particularly significant.

    DC

  287. Tim Folkerts says:

    Stephen says (regarding Verkley): “His view is impossible because there is always convection so if it were to have the effect of taking the atmosphere away from equilibrium then there would be a permanent imbalance at top of atmosphere.”

    But there IS a permanent imbalance! The top is always colder than the bottom. If the system were in equilibrium, then temperatures would be the same everywhere in the atmosphere. In thermodynaic equilibrium, there can be no temperature difference. (There can also be no bulk motion within a system at equilibrium, so the very presence of convection by definition says the atmosphere is not at equilibrium.)

  288. Tim Folkerts says:

    Trick says: “This g/Cp really, is an approximation that is not as close as Poisson lapse…

    Everything I have seen says these two are the same thing — there are numerous sources that derive g/Cp from the Poisson equation. Now, I grant you that either of these is just an approximation to the ELR, but they seem to be exactly the same approximation!

  289. Stephen Wilde says:

    Tim.

    Over time the top of atmosphere is balanced with energy in equalling energy out.

    If anything creates an imbalance between energy out and energy in at a constant mass, gravity and insolation then convection works to correct it..

    In so far as convection fails to correct it then changes in volume mop up the residual effects of any increase in surface temperature so that TOA energy exchange returns towards balance.

    In a thin atmosphere aided by water vapour the radiative effects of 0.004% of the atmosphere are as near zero as makes no difference.

    When the system is in equilibrium ENERGY is the same everywhere in the atmosphere NOT TEMPERATURE.

    As one goes up KE gets replaced by PE but the energy content stays the same.

    The temperature difference between top and surface does not represent an imbalance. It merely reflects the direction and rate of energy flow through the atmosphere.

    Anyway, note my subsequent comments.

    The viscosity of the atmosphere determines how much of a change in equilibrium temperature is required by an increase in forcing other than from mass, gravity and insolation because it affects the cooling efficiency of convection by making it faster or slower.

    Viscosity is determined by mass and gravity so changes in anything other than mass and gravity will not be significant and small changes in volume and lapse rate slopes would easily offset any residual effect at the surface after convection has done its bit.

    That is why the atmospheres of Earth and Venus show much the same temperature at the same atmospheric pressure adjusted only for distance from the sun.

    Atmospheric heights change so that the Effective Radiation Level is at the same temperature but at a different height.

    The temperature of the ERL does not change. AGW theory says the ERL is at a colder location so that the surface must become warmer.

    That must be wrong.

    A higher ERL at the same temperature means faster throughput to offset any warming effect from forcing elements other than mass, gravity and insolation.

    The reduction of mass in each unit of volume when expansion occurs must have a cooling effect as per the Gas Laws.

  290. Tim Folkerts says:

    Stephen says: “Over time the top of atmosphere is balanced with energy in equalling energy out.
    If anything creates an imbalance between energy out and energy in at a constant mass, gravity and insolation then convection works to correct it.”

    You are describing “steady-state”, not “equilibrium” here.

    As for the rest of what you write, I see lots of claims, with no calculations to back them up. Some of the things you say are partially right — adding energy to the atmosphere DOES make it expand, but this does NOT keep the temperature from also increasing.

    And several things you say are wrong.

    “When the system is in equilibrium ENERGY is the same everywhere in the atmosphere NOT TEMPERATURE.
    I don’t know what else to say except this is simply wrong — thermal equilibrium requires temperature to be the same.

    “As one goes up KE gets replaced by PE but the energy content stays the same.
    This is approximately correct for the non-equilibrium atmosphere.

    “The temperature difference between top and surface does not represent an imbalance. It merely reflects the direction and rate of energy flow through the atmosphere.
    Again, this is “steady-state” but not “equilibrium”.

    “AGW theory says the ERL is at a colder location so that the surface must become warmer.”
    This makes no sense to me. The “ELR” is a rate that extends through the entire atmosphere, not “at a location”. Perhaps you meant “ToA” rather than “ELR”?

    “The reduction of mass in each unit of volume when expansion occurs must have a cooling effect as per the Gas Laws.
    Yes, there is a cooling effect that REDUCES (but does not eliminate) the warming.

    Start with a parcel of air — for example 1 m^3 @ 300 K @ 1 Atm. Add some heat (maybe 1000 J) WITHOUT allowing it to expand — it will get warmer than 300 K and it will get to a pressure above 1 Atm. Now allow it to expand back to 1 Atm (without losing heat to the surroundings). It will expand and cool (your “cooling effect”) — but it will STILL be above 300 K! Do the calculations — it is not difficult.

  291. Trick says:

    Tim F. 8:26pm: Ohhhh…k… Let’s assume Tim’s ELR means the US Standard. Run some numbers Tim*.

    1) David’s Fig. 5 from Fig. 7: Lapse = 5K/km base of atm. = 6.4K/km Base + Bulk of atm.

    2) g/Cp = 9.75956K/km meaning at 1km the Fig. 7 temp. would show 277.2404K using NASA numbers instead of Fig. 7 = 282K.

    3) Poisson lapse T(1km) = To(P(1km)/Po)^R/Cp = 287K(P(1km)/Po)^.286. David doesn’t tell us pressures so use the US standard atm. p. 53: T(1km)=287(898.76/1013.25)^.286 = 277.32 or 9.680K/km

    4) US ELR = 6.499 0km to 1km which I wish David had used in Fig.s 5 & 7

    So Poisson is slightly different (~.08K) at 1km than g/Cp. At tropopause or even David’s 10km up, the difference is larger, I will let others do that math & data lookup for fun & exciting homework. This difference is due to g/Cp assuming T is constant where Poisson lapse is assuming T not constant in the integration.

    Geez, all these different lapse rates don’t match up at all, not one; some of it might be from rounding issues; still Stephen must think the atm. will blow off. Which one doesn’t blow off atm. I wonder.

    Whenever someone writes about “the lapse rate” which one is meant? Dunno, hard to tell except for one poster:

    David top post:

    “…thus distorting the temperature lapse rate?”
    “…to take account of the lapse rate…”

    Kristian:

    “…via the lapse rate…”
    “…through the lapse rate…”
    “The lapse rate in no way controls…”

    Stephen:

    “…which the lapse rate slope…”

    Clive:

    “Water is different because it determines the lapse rate…”
    “…textbooks (for example Houghton’s) show the lapse rate as a straight line…”

    Trick:

    “The Poisson lapse rate…”
    “…the US Standard Atmosphere lapse rate…”

    ******

    *Gotcha’.

    *For an even better, in depth, exciting & fun description of approx. g/Cp lapse and exact, ideal Poisson lapse differences see my favorite text, Bohren 1998. Or Wallace&Hobbs pp. 77-78.

    *This is why I suggested David use the ground rule of US Standard Atm. lapse in Part 2 namely Fig.s 5&7. There is still possibility to work US Standard lapse rate into Part 3 figures!

  292. clivebest says:

    David writes “What would be interesting for now is for you to explain why a 2:1 ratio is particularly significant.”.

    SU(1-g) = OLR where SU = 396 watts/m2 and OLR = 239 watts/m2

    In other words the net effect of the atmosphere is roughly to reduce the radiation emitted by the surface by about 1/3

    At least I have a rational argument as to why cloud tops emit 50 W/m2 through the IR window to space. I have not seen a similar one for why it should be 30 W//m2.

    Clive

  293. Trick says, March 2, 2013 at 5:51 am: This is why I suggested David use the ground rule of US Standard Atm. lapse in Part 2 namely Fig.s 5&7. There is still possibility to work US Standard lapse rate into Part 3 figures!

    Trick,

    I don’t know why you are going on and on about this!

    Both in Part I and Part II I have always used the US Standard lapse rate of 6.5K/kmin to calculate the temperatures at various heights above the surface as shown in Figs. 1 ,3 and 7. As you pointed out, I inadvertently missed out temperature figures altogether in Fig. 5.

    To calculate the absolute temperatures, I started from a surface temperature of 288K rather than Trenberth’s 289K figure because 288K is the US Standard Atmosphere value for surface level temperature. In any case, it makes a trivial 1K difference at 10km.

    (N.B. the 287K temperature shown for the bottom surface of the Base of the Atmosphere is not calculated using the lapse rate. As mentioned in the text, it is a concession to the fact that there is some controversy over a minor observed difference between surface and atmosphere-at-the-surface – an interesting debate in its own right but not relevant to the main purpose of this model.)

    DC

  294. clivebest says, March 2, 2013 at 8:56 am

    Clive,

    Thanks for the rationale. I do remember now. You may well be right. Have you contacted Trenberth et. al. about it? Although they are firmly in the warmist camp they are professional academics and should respond to a reasoned submission.

    However, here in this blog trail we have set our faces against arguing any more over the Trenberth values used in my model since our objective isn’t to verify them but to use them as ‘placeholders’ in our discussions to avoid too much abstraction.

  295. While Tim Folkerts ponders my request of yesterday, March 1, 2013 at 9:26 am, where I asked …

    Since this new angle on the warmist creed [output throttling] is relatively unknown to most people (if you Google “global warming” all you get is the usual guff about radiation causing throughput throttling), could you for a start give us some digestible references on the phenomenon? Thanks!

    … I have been doing some investigating myself and I found this here and here.
    http://chriscolose.wordpress.com/2008/03/09/physics-of-the-greenhouse-effect-pt-1/
    http://chriscolose.wordpress.com/2008/03/09/physics-of-the-greenhouse-effect-pt-2/

    [NOTE: None of these links seem to work properly in my browser (IE9). You may have to copy-and-paste the URL to a new browser instance. TC/TB can you help?]

    [The ‘Part 2’ link doesn’t seem to work even using copy-and-paste. But you can reach it by clicking on the ‘Part 2’ link at the top of the Part 1 article.]

    Chris Colose is a well known warmist proselytiser but he sure can write well. Just the place to go, perhaps, to listen to their side of the argument.

    No quantitative justifications in sight though. Still searching…

    DC

  296. Stephen Wilde says:

    “No quantitative justifications in sight though. Still searching”

    Yes, funny that.

    No such quantification from warmists but they keep asking me for it whenever simple logic doesn’t suit them.

    And now Tim’s obfuscation extends to relying on a difference between equilibrium and steady state.

  297. Stephen Wilde says:

    Tim has also mixed up Effective Radiating Level (ERL) with Environmental Lapse Rate (ELR) despite me having been clear about my usage earlier.

  298. Tim Folkerts says:

    “Tim has also mixed up Effective Radiating Level (ERL) with Environmental Lapse Rate (ELR) …

    I will admit I missed that one. The two abbreviations are so similar and I clear misread one for the other. Sorry about that.

    When read properly, then I completely agree that:
    “AGW theory says the ERL is at a colder location so that the surface must become warmer.”
    That follows from basic conservation of energy.

    “And now Tim’s obfuscation …
    If insisting on correct language (“steady-state” vs “equilibrium”) and correct physics (thermal equilibrium = “equal temperature”, not “equal energy”) is “obfuscation”, then I guess I am guilty as charged!

    And the reason we ask for “more than simple logic” is that your “simple logic” does not conform to freshman physics. For example, if you heat the air, it will both expand and warm. If you want to claim something different, then you need to do some serious work to show why everyone else is wrong and you are right.

  299. Tim Folkerts says:

    David asks: “Since this new angle on the warmist creed [output throttling] is relatively unknown to most people (if you Google “global warming” all you get is the usual guff about radiation causing throughput throttling), could you for a start give us some digestible references on the phenomenon? Thanks! …”

    I’ve been thinking about this one, and I am not sure quite how to respond.
    1) I don’t think “effective radiating levels” or “ToA radiation” or “GHGs limit the radiation to space” is a “new angle” per se.
    2) I don’t think this explanation in any way contradicts the typical explanations on many webpages. It is the other side of the same coin.
    3) Just because something is unknown to many people doesn’t mean it is unknown.
    4) Just because a lot of people have misconceptions does not mean that experts have those same misconceptions.
    5) “Digestible reference” depends on what people have the stomach for (pun intended).

    That said, here is one answer to the challenge. One of the most common models for explaining the GHE is the “glass shell” model. Sunlight gets in, but thermal IR doesn’t get out, and there is no atmosphere. I would call this “output throttling” since energy moves freely EXCEPT at that shell. This model results in a 2^(1/4) = 19% increase in surface temperature — from example from 255 K for a bare planet to 303 K with the shell in place. (Interestingly, in this model, the main effect of adding a non-GHG atmosphere between the planet and the shell would be to COOL the surface, not to warm it further — the atmosphere INCREASES the throughput between surface and “ToA”).

  300. Stephen Wilde says:

    Tim

    The ERL does not change to a colder location. Instead it stays the same temperature but the height changes.

    As regards obfuscation I spoke of thermal equilibrium at top of atmosphere i.e. energy in equalling energy out over time. Your response went off on a tangent referring to the temperature gradient from surface to TOA.

    I know that heated air both warms and expands but if it also changes height more of the available KE gets converted to PE which is a cooling effect.

    So do GHGs actually heat anything if their extra energy can go straight to PE ?

    The issue is as to how much of the potential warming from added energy (not necessarily heat) is offset by the cooling effect of converting more KE to PE when an atmosphere expands against gravity.

    You say that a significant warming effect remains but you have never proved or demonstrated it.

    As I said above, the amount of temperature rise that results from adding energy depends on density/viscosity because that affects the speed and thus efficiency of convection.

    In any event you have yet to demonstrate that CO2 molecules add energy in the first place given their ability to provide an additional radiative window to space.

    They might have a warming effect in an enclosed container but an atmosphere open to space is another matter.

    On Earth we have a very thin atmosphere which convects freely. In addition, convection is enhanced because water vapour is lighter than air. Any thermal effect from 0.004% of the atmosphere would therefore be indistinguishable from zero even if CO2 does add energy.

    On balance I don’t accept that radiative characteristics do add heat or energy to an atmosphere. Instead, radiative transfer within an atmosphere is the consequence of the temperature set by mass, gravity and insolation.

    Mass is king.