New talkshop visitor ‘David’ has dropped a fruitful link on Wayne Jackson’s recent thread which, after a bit of sleuthing via AstroBio.net, leads to a new paper from the Trieste Astrobiology Group led by Giovanni Vladilo. This will be of great interest to our friends Nikolov and Zeller, because it vindicates their contention that atmospheric pressure is the principle determinant of planetary surface temperatures. However, there is a twist. As well as affecting the near surface heat capacity, evaporation rates and meridional energy transport, atmospheric pressure also affects the atmospheric optical depth of atmospheres, and this explains the role of ‘greenhouse gases’ and their radiative properties in contributing to the overall distribution and magnitude of energy at planetary surfaces. Although not dscussed in the paper, I think it will also be the case that regardless of extra emissions of a greenhouse gas such as carbon dioxide, since the pressure is the primary variable, the optical depth will remain constant, as NASA Physicist Ferenc Miskolzci found. If so, the Man Made Greenhouse Panic is over.
The pressure-dependent habitable zone is shown in the left figure below. The circles indicate solutions of the climate simulations with mean global annual habitability h>0. The area of the circles is proportional to the habitability h; the colors are coded according to the mean annual global surface temperature, Tm. The size and color scales are shown in the legend. The solid lines are contours of equal mean temperature Tm=0 C (magenta), 60 C (red) and 120 C (black). (Click for larger image)
The key passage from the paper is this one:
4.2.1. Surface Pressure and Planet Temperature Variations of surface pressure affect the temperature in two ways. First, for a given atmospheric composition, the infrared optical depth of the atmosphere will increase with pressure. As a result, a rise of [pressure] will always lead to a rise of the [radiative] greenhouse effect and temperature. Second, the horizontal heat transport increases with pressure. In our model, this is reflected by the linear increase with [pressure] of the diffusion coefficient D (Equation (A5), Appendix A.2). At variance with the first effect, it is not straightforward to predict how the temperature will react to a variation of the horizontal transport. In the case of Earth, our EBM calculations predict a rise of the mean temperature with increasing D. This is due to the fact that the increased diffusion from the equator to the poles tends to reduce the polar ice covers and, as a consequence, to reduce the albedo and raise the temperature.
The main thrust of the paper is the effect of pressure has in widening or narrowing the ‘habitable zone’ for a planet in relation to distance from its star.
In the animation above we show the effects of pressure on the habitable zone. All model parameters are set equal to the Earth value, except for the stellar insolation and the surface pressure. As pressure increases, the fractional habitability increases and the habitable zone becomes wider. (Click for animation in new window)
At the Trieste Astobiology Group’s website, further scenarios testing the model are also animated:
More animations showing the seasonal evolution of the surface temperature are provided here. This is the Earth at p=0.2 bar: one can see that, due to the low surface pressure, the mean global annual temperature is low (Tm=-12 C) and the seasonal excursions of the zonal temperatures are quite intense. This is the Earth at p=5 bar: in this case, due to the high pressure, the mean global annual temperature is high (Tm=+52 C) and the seasonal excursions of the zonal temperatures are quite moderate. A more exotic case is shown here, we you can see an Earth-like planet with axis obliquity at 90 degrees and p=0.3 bar: in this case an equatorial belt of ices is formed as a consequence of the high inclination of the planet rotation axis.
This pdf of the group’s 2012 AGU presentation makes the effect of pressure on temperature even clearer. Look at the temperature difference for exoplanet GI581d between 7 and 8 bar of pressure! H/T @geschichtenpost
http://wwwuser.oats.inaf.it/astrobiology/docs/EBM_EGU2012.pdf
Tallbloke's Talkshop 
Everybody will be able to say they had known about this all along. But hundreds of unanswered questions about Venus have just been vindicated.
This is a game changer because the model is built on simple equations we can get to grips with.
So compared to an Earth with 1/4 of a atm, how much does 1 atm added to the warming of Earth?
Or if there was suppose to be 33 degrees added by greenhouse gas, how of the 33 C is from
Earth’s moderately thick atmosphere?
I suspect if Earth had 1/2 atm rather than 1 atm, it would warmer.
And I think Earth’s average temperature is nearly all about the fact that Earth is a planet
with surface area mostly ocean. So only if reducing the amount of atmosphere affects the temperature of the ocean [so a low enough pressure that water boils at 35 C or lower].
It seems to me that significantly less atmosphere than 1 atm, would affect amount of cloud cover.
And less atmosphere will get colder nights. And less atmosphere gives less atmospheric convection. But are relatively minor affects in terms of global average temperature, if you have a planet mostly covered with water.
Looks like Harry Huffman’s work on the comparison of Venus and Earth mean global temperature at the same level of atmospheric pressure being identical is fully supported. The CAGW premise that it is CO2 and other GHGs levels that dictates temperature is now doomed!
This pdf of the group’s 2012 AGU presentation makes the effect of pressure on temperature even clearer. Look at the temperature difference for exoplanet GI581d between 7 and 8 bar of pressure! H/T @geschichtenpost
Click to access EBM_EGU2012.pdf
The changes in energy transport within the atmosphere as a result of pressure changes can only be manifested in the form of volume and circulation changes as per my various propositions.
The issue boils down to density.
Under more pressure all the constituent molecules move closer together resulting in higher density, reduced atmospheric volume, more energy in the form of KE in place of PE, an increased optical depth (density is a factor in slowing throughput of energy and so affects optical depth) and produces a higher temperature.
Under less pressure the opposite occurs.
For a planet with an atmosphere, pressure at the surface cannot change however much the atmosphere expands and contracts but if expansion or contraction occurs there is a pressure change within each unit of atmospheric volume at every point in the vertical plane as one moves away from the surface.
Since pressure affects the lapse rate such expansion and contraction potentially moves the actual lapse rate away from the lapse rate set by mass and gravity.
However, energy in and out at top of atmosphere must always balance over time if an atmosphere is to be retained so the only thing that can change to retain that balance when expansion or contraction occurs is atmospheric circulation within the expanded or contracted atmosphere.
So, wherever any forcing element (such as the radiative characteristics of constituent molecules) seeks to change the ideal lapse rate then circulation changes somewhere else in the atmosphere will adjust to negate it overall.
Latitudinal climate zone shifts and changes in jet stream behaviour are the adjustment process in action.
I have been making this point since 2008.
“the increased diffusion from the equator to the poles tends to reduce the polar ice covers and, as a consequence, to reduce the albedo and raise the temperature.”
When internal system changes work to affect albedo then that effect mimics a change in top of atmosphere insolation which DOES affect system temperature significantly for most planets
However on a water planet the hydrological cycle then kicks in to help maintain stability due to the enormous efficiency of the phase change relating to water with its 5:1 ratio.
Hence the relatively small rise in Earth’s temperature since the early faint sun.
Nonetheless, the negative system response from the changed speed of the hydrological cycle must still manifest itself in changes in atmospheric volume and the positions of the climate zones and behaviour of the jets.
To my mind this all fits together simply and beautifully.
An interesting feature of that paper is that although they recognise the connection between pressure and temperature they then go on to say that at current pressure of 1bar if applied at the time of the early faint sun would have resulted in frozen oceans.
They then go on to assume that CO2 made it warm enough for liquid oceans to be present at that time and try to ascertain the then levels of CO2.
However, there is evidence that the atmosphere was bigger and denser back then having lost mass to space in the meantime so the liquid oceans could just as likely have been due to higher atmospheric mass and greater surface pressure rather than CO2.
It is often proposed that large winged dinosaurs could only have evolved in a more dense atmosphere than that of today.
It is also possible that a lower global albedo from less clouds back then would have allowed more energy into the oceans to allow them to be in liquid form despite the fainter sun.
If as I propose the hydrological cycle serves as a thermostat then the weaker sun at the time would have produced a slower hydro cycle with less clouds a lower global albedo and more of the available solar energy able to enter the oceans.
Also a different landmass configuration could have allowed more energy to be retained by the oceans.
There are many reasons why the oceans then could have been in liquid form for reasons other than more CO2.
It will be interesting to see if this holds up under scrutiny.
Reblogged this on CraigM350.
I wonder where the sun’s variations directly effecting the earth’s atmosphere comes into this?
http://phys.org/news202054025.html
By how much does the small solar effect modulate the air pressure and thus the global temperature?
Q from a Luddite. If pressure controls temperature, as this article shows. What controls pressure?
One of the comments says that as pressure rises, the atmosphere acts as a thermostat so there is less cloud, lower pole ice cover etc. if so is the lower than average N.pole ice cover a reaction to the cooling global temperatures
Perhaps there is some data to indicate pressure and density changes of the atmosphere in relation to the Solar cycle.
‘SABER is one of four instruments on the TIMED spacecraft launched in December 2001. TIMED studies the Earth’s mesosphere and lower thermosphere, the least explored and least understood region of our atmosphere.
“SABER has a unique, continuous record of over 3,700 days observation of the climate and energy balance of the Earth’s upper and outer atmosphere,” Mlynczak said.
“From this, we are learning with each event how sensitive this region of the Earth’s atmosphere is to short- and long-term variability of the Sun,” he said. “We have documented the decline of the prior solar cycle, the deep minimum and the ‘ground state’ of the atmosphere during that time, and are now seeing the uptick.”‘
http://www.nasa.gov/mission_pages/sunearth/news/saber-solarstorm.html
tckev.
Solar variations don’t affect surface pressure but they do cause the atmosphere to expand or contract thereby changing density and pressure up through the vertical column which in turn affects the rate at which energy can flow through.
It is necessary to distinguish between two sorts of solar effect:
i) Changes in the total amount of energy being delivered to ToA.
ii) Changes in the composition of the atmosphere resulting from changes in the mix of solar particles and wavelengths which then affect the proportion of ToA insolation that reaches the surface and /or enters the oceans by altering albedo and optical depth.
The latter mimics the former by allowing the system to warm or cool but circulation changes in air and oceans then develop so as to keep the ToA energy exchange stable by readjusting the rate of energy throughput.
The former has the ability to cause a permanent change in system energy content but on a water planet the effect is much mitigated.
The paper says ‘it is not straightforward to predict how the temperature will react to a variation of the horizontal transport.’
Presumably on a local/regional level? The Standard Atmosphere has no problem with it.
http://en.wikipedia.org/wiki/International_Standard_Atmosphere
tckev and Andrew: “what controls pressure?”
Atmospheric mass and Gravity and the density of the Earth sets the pressure at the surface. You need to consider this more in terms of the ‘average background state of affairs’ rather than looking for explanations of short terms change in climate. The key point is that gravity acting on the mass of the atmosphere pulls it against the surface creating pressure. This makes the near surface air denser, raising it’s heat capacity. That makes it able to retain heat better on the night side of the planet. The pressure also limits the rate of evaporation of the ocean, making it more difficult for the ocean to lose energy, so it has to rise to a higher temperature in order to do so.
This article I wrote a while back might help:
Where that leads to is the fact that other factors apart from the radiative properties of ‘greenhouse gases’ determine the surface temperature of planets. Which means that the 33C the IPCC claims for the effect of ‘Greenhouse gases’ is overblown by a long way. This in turn means that any effect of extra co2 emitted by humans will be less than they claim – it’s Probably only around a fifth. And that’s before we reduce the warming they claim because the sensitivity is more like 0.4-1.6C per doubling than the 3C they believe.
In brief, co2 induced warming is a dead letter.
Yes, I see. unfortunately due to a PC crash I’ve lost the original NASA report but within the link I cited is this little teaser –
My question is somewhat childish – where has it gone and what is the outcome of this?
“The pressure also limits the rate of evaporation of the ocean”
Not sure that pressure limits the rate. Factors such as windiness, radiation impacting the surface (without being absorbed) and relative humidity seem to have more to do with the rate
Pressure does however limit the energy cost of a given amount of evaporation by adjusting the ratio between energy required to induce evaporation and the energy taken up by the process of evaporation.
At 1 bar pressure that is a ratio of 1:5.
So pressure effectively rations the amount of energy that can be extracted from the oceans by a given amount of evaporation and thereby determines ocean temperature at a given atmospheric pressure.
@Stephen Wilde, and @tallbloke
I have also been wondering that as the jet stream circling our globe at a certain height maintaining a reasonably constant circumference, then as outline by NASA the atmosphere(under influence of the sun) shrinks then the circumference that the jet stream occupies reduces but the energy within the jet stream does not reduce as fast. The only method therefore for the jet stream to dissipate the energy in this smaller circumference is to wobble more and so become more loopy. (in accordance with natures usual path of least resistance)
Or am I barking up the wrong tree?
tckev
The atmosphere as a whole does not shrink or expand evenly.
There are multiple internal system forcing elements constantly seeking to disturb equilibrium.
What seems to happen is that oceanic influences dominate from the equator and solar effects dominate from the poles and the two are in constant interaction.
When the jets shift poleward they are compressed into shorter, faster bands with little room for manoeuvre and when they shift equatorward they expand into longer slower bands and can loop about more freely in a greater amount of space.
“Q from a Luddite. If pressure controls temperature, as this article shows. What controls pressure?”
Andrew, the total mass, that is when keeping the mass of the central body constant therefore also keeping the gravitational acceleration constant. If an asteroid of adequate size were to collide or closely skim Earth, some of the total mass of the atmosphere would reach escape velocity and the Earth surface temperature would then end up lower, all else remaining constant. This effect of course is not taking into account any difference in solar output, changes in the orbit, or albedo changes (governed mainly by mean cloud cover). Also if the overall longwave optical thickness were to change that would affect these calculations also. That is the amount of “window” non-interacting LW radiation escaping directly upward and this radiation must be excluded from what is half redirected downward by the isotropic GHGs. This is where most scientists seem to loose the reality, they don’t exclude the “window” portion and this is what Miskolczi was partially measuring, he couldn’t measure it’s totality for that seems immeasurable at this point but what he could measure stays constant as co2 concentration rises… as I expected long ago, it’s been a long haul reaching this point to finally “getting it”.
I think if you double Earth’s atmosphere, double the oxygen, nitrogen, argon, and even the CO2,
earth would have a lower average temperature.
Simply due to less sunlight reaching the surface of Earth.
So with doubled atmosphere we would not get 1000 watts per square meter as the amount energy
reaching the surface on clear day and sun at zenith.
Instead it would around 900 watts per square meter. And this would large effect in cooling earth average temperature.
And I see no reason the doubled atmosphere would increase the ocean temperature. Such an effect would increase the size of the Earth’s troposphere, but it seems the atmosphere would cooler and would not hold more H2O gas. because of higher troposphere it seems mountains would less effect upon causing rain.
If you double the gravity you double pressure with same amount an atmosphere, this in general should increase global temperatures. Doubling gravity should increase the speed of air molecules
of atmosphere by a very slight amount, but be quite a bit more significant in terms of temperature [and average temperature].
I am going to be radical.
1. the low pressure regime is dominated by solar energy
2. the high pressure regime is dominated by nuclear decay and primaeval heat.
Consider an atmosphere as what it is, an attenuator.
tchannon
All heat generated at the surface causes expansion of the air above that surface, a reduction in density and thus weight relative to surrounding air and a tendency for the heated air to rise whereupon the reduction in pressure with height maintains the density difference so that rising continues until something else puts a stop to it such as the temperature inversion at the troposphere.
Rising air results in low pressure and descending air results in high pressure.
Whether the heat is provided by the sun or by nuclear heat and primeval heat the result is the same.
Heated air causes BOTH low pressure from rising air and high pressure from the subsequent descent giving rise to a circulation. It makes no difference as to how the heat arrives at the surface.
gbaikie says:
“I think if you double Earth’s atmosphere, double the oxygen, nitrogen, argon, and even the CO2,
earth would have a lower average temperature.”
The more mass in the atmosphere the higher the system energy content becomes and the higher the average surface temperature.
Likewise, if one increases the strength of the gravitational field which compresses the atmosphere thereby increasing density which allows it to retain solar energy for longer.
Likewise increasing ToA insolation which means that more energy is flowing through at any given moment.
The effect of an atmosphere is to lower the peak temperature on the day side and increase the lowest temperature on the night side for an increase in average temperature overall.
The more mass the greater the effect.
Changes in any other factors only result in circulation changes so as to adjust energy throughput so that radiative balance at ToA is maintained.
I really don’t see how this is a “game-changer” in any way.
* The model still includes GHG’s as a critical part of the modeling.
* The model still gives about the right results for earth using “standard” energy balance techniques.
* It is no surprise that more pressure should warm a planet’s surface. This is completely in line with a radiative greenhouse effect.
This does not yet “vindicate” Nikolov and Zeller, whose hypothesis seems to be that pressure ALONE (even with 0.000% GHGs in the atmosphere) would still be able to account for earth’s warming from simple BB limitations of ~ 255 K to current temperatures of ~ 288 K.
In fact, this study CONFIRMS the greenhouse effect and refutes Nikolov and Zeller! Check near the end of their paper.
Click to access EBM_EGU2012.pdf
They consider the conditions of a hypothetical planet like the early earth, and vary ONLY the CO2 concentration, keeping total pressure the same. More CO2 with the same total pressure dramatically warms the earth! And these are much higher concentrations of CO2 than current conditions, so there is no way to argue “saturation” effects should limit warming from more CO2.
[Reply] Tim is wearing his ‘selectaglasses'(tm) again
“The model still includes GHG’s as a critical part of the modelling.”
Of course it does.
But then consider the total mass of GHGs as compared to the total mass of our atmosphere.
The paper assumes that the atmosphere was still 1bar all that time ago so that the required additional energy to make the oceans liquid was down to CO2 alone.
Pretty stupid in my view.
The atmosphere long ago was more massive so their basic assumption is flawed.
They accept that pressure from mass influences temperature.
Then they assume a constant mass right back to the time of the early faint sun and because that assumption leads to an impossible conclusion they assume that CO2 is the only parameter that varied and ascribe a totally inappropriate forcing power to CO2 to cover up the stupidity of the initial assumption.
Priceless.
Ned has emailed me with some pointers to shortcomings in their analysis too. I’ll post them later.
Stephen, I don’t think there was an attempt to accurately predict what the actual earth was like several billion years ago. Rather, they were exploring the consequences of their model in different scenarios. They even conclude
Sure, they could have included other scenarios (for example, keeping CO2 constant and increasing N2 instead, or making the oceans bigger or smaller). A quick look around the web doesn’t turn up much info about the exact composition or pressure of the atmosphere 3+ billion years ago, so the authors apparently picked a few “illustrative” scenarios. Not “stupid” per se — just a first look at how the model works and how it could be used.
That does not invalidate the trend they discovered. More CO2 = higher temperatures when everything else was held constant. That sounds pretty much like what many people are claiming in terms of CO2 today.
(Of course, the model itself might have a variety of flaws, but that is a different issue. It people like the model, then the only conclusion seems to be that more CO2 will indeed warm the planet).
Stephen Wilde.. You know I agree but that is only so far, ie. you have not understood.
An atmosphere is literally an attenuator to energy flow.
For an extreme atmosphere solar can play out at the top but little will reach the surface. Flow is very restricted in both directions. Ground heat then assumes a much greater role.
This fits with a similar regime existing in all the places where we have been able to measure but it does not follow that this is a single true law. I am suggesting a second effect which becomes dominant under thick atmosphere. This too seems consistent with what we know.
How much sunlight reaches 1,000km down into Jupiter?
Excess heat is supposed to be coming out. This isn’t from sunshine.
The second effect is negligible for earth but is I suspect significant for venus.
Ned Nikolov says:
I’m reading the Vladilo et al paper right now and see a number of serious issues with their formulation of dependencies of heat capacity and outgoing LW radiation on pressure. These claimed dependencies are NOT physical and nonexistent in reality! For example, it is a standard concept in thermodynamics that the heat capacity has NO dependency whatsoever on pressure; see this short video by a professor at Colorado University in Boulder:
The only parameter in their simple model that really depends on pressure is diffusivity. However, in the real atmosphere, molecular diffusivity only pays a minor role since most of the meridional heat transport is done through large scale currents driven by pressure gradients.
I will send you more feedback after I go through the whole paper and have a chance to capture the details. However, so far this paper seems to be a great disappointment – the authors show an ‘effect ‘of pressure on temperature using the wrong mechanisms! This is not helping our understanding, instead it further muddies the waters of climate science.
I think I said this several times before on the blogs – the thermodynamic part of climate models is based on the gas law and that’s all good. However, the problem is that, in the solution, the convective heat exchange is always decoupled from radiative transfer in a sense that these two key heat transport mechanisms are NOT solved simultaneously as they occur in reality. The effect of this artificial decoupling is the simulated increase of surface temperature with rising CO2 (i.e. with increasing atmospheric LW emissivity or opacity). This result is unphysical and violates the conservation law … None of the climate scientists I’ve talked to (including Richard Lindzen) appear to be aware of this problem.
Tim Folkerts said:
“More CO2 = higher temperatures when everything else was held constant. That sounds pretty much like what many people are claiming in terms of CO2 today.”
Yes, Tim, but only when they attribute a specific net thermal effect to more CO2 (in itself not proven) without also taking into account negative (as opposed to their assumed positive) system responses so the model is not real. It has not been demonstrated that the net effect of more CO2 is warming. cooling or neutral in the real world so the model is a fiction.
tchannon:
Ground heating gives low pressure whether it is from solar radiation or from the Earth itself.
How could nuclear decay or primeval heat cause high pressure ?
As regards Ned’s comment I just question his decoupling of pressure from a thermal effect.
Pressure is a result of mass plus gravity so:
i) Higher pressure from more mass would raise temperature and
ii) Higher pressure from stronger gravity would increase density and reduce energy flow rates to raise temperature.
So, I agree that increased pressure in itself has no direct effect but (indirectly) increased pressure is a result of more mass or more gravity which do both have a warming effect.
Maybe there is a terminological issue in there somewhere because I agree with Ned in general ?
“For example, it is a standard concept in thermodynamics that the heat capacity has NO dependency whatsoever on pressure … “
No, that is specifically for an ideal gas. Real gases can and do change (although not by very much). http://www.engineeringtoolbox.com/air-specific-heat-various-pressures-d_1535.html
“molecular diffusivity only pays a minor role …”
This is a mis-characterization of the original paper. “Diffusion” is a catch-all term for any transport mechanism — including the large-scale currents.
“This result is unphysical and violates the conservation law ”
I would be interested to know which specific conservation law Ned feels is violated by which specific result.
Stephen Wilde, I think it is cross purposes. I didn’t mention pressure as related, merely that a thick atmosphere will retard flow. Therefore heat independent of solar has more effect.
I raised this because purely considering solar might be a mistake and confounding factors are best known about.
Ned seems to regard diffusivity as limited to conduction from one molecule to another.
The paper under discussion seems to regard diffusion as the totality of non radiative energy transport mechanisms.
What the paper misses is that what it calls the diffusion coefficient is variable and dependent on density which brings into play the issue of expansion and contraction affecting density and thus the so called diffusion coefficient.
So if GHGs slow down energy throughput as proposed by AGW theory then expansion can occur without necessarily requiring an increase in surface temperature or system energy content. Just more energy in the air is enough to cause expansion without involving the surface. A change in lapse rate slope will do the trick.
However, as soon as expansion occurs the diffusion coefficient changes due to reduced density in the vertical column and that accelerates energy throughput again to negate the effect of more GHGs.
That is how ToA radiative balance is maintained when the amount of GHGs changes.
Comparing Climates: From Earth to Exoplanets
http://astrobiology.com/2013/05/comparing-climates-from-earth-to-exoplanets.html
A Comparative Climatology Symposium was held at NASA Headquarters in Washington, DC on Tuesday, May 7. The symposium focused on new approaches to climate research by highlighting the similarities and contrasts between the environments of the terrestrial planets Venus, Earth, Mars, and Saturn’s smoggy moon Titan. The symposium also included discussions about exoplanets, the Sun, and past, present and future space missions.
As for Venus, Grinspoon said scientists believe current-day volcanism on Venus is thought to be necessary to sustain the planet’s thick clouds. He added that the active surface has eradicated most ancient rocks, preventing us from easily understanding Venus’ early history.
Grinspoon also discussed the unique climate of Titan, noting that the methane cycle on this moon of Saturn is “like Earth’s hydrological cycle on steroids.”
Studying the climates of Mars, Venus, Titan and even exoplanets could help us refine our climate models of the Earth. However, Grinspoon said that “clouds are the biggest uncertainty in understanding the past of Venus and predicting the future of Earth.”
I was really excited after I first heard of this paper from Rog. I was also highly curious about how the authors approached the pressure-temperature relationship on a planetary scale. So, I set some time aside and carefully read through it … Here are my comments:
1) This is the first peer-reviewed paper I have seen that attempts to directly relate planetary surface temperature to total atmospheric pressure using a bottom-up energy balance approach based on first principles (or close to them).
2) The authors got the pressure-temperature relationship correctly, but only in qualitative terms, not quantitatively. The main reason for this, in my opinion, is because they approached the problem from the wrong end … The authors assume a priori that pressure ONLY influences temperature through its effect on atmospheric infrared opacity (or optical depth) following the standard Greenhouse Theory, which claims that it’s the back radiation that warms the surface above the level of an airless environment. So, in their approach and model construction, the pressure only directly affects the absorption of outgoing LW radiation. In reality, however, the pressure directly affect the temperature, while the back radiation is simply a product of temperature and atmospheric thermal emissivity.
In their heat diffusion model (Eq. 1, see also the Appendix), pressure is assumed to control the effective heat capacity, the heat diffusion coefficient, and the outgoing long-wave radiation (OLR). Everyone who knows basic thermodynamics will immediately note that these assumptions are physically incorrect. Heat capacity and OLR have absolutely no pressure dependency in reality. The heat diffusion coefficient does have a pressure dependency through thermal conductivity, but molecular diffusion of heat only plays a minor role in atmospheric heat transport, which is primarily controlled by large-scale turbulent fluxes of latent and sensible heat driven by pressure gradients. Reading through the Appendix (section A.3), one learns that the authors have basically invented a new ‘physical’ relationship between OLR and pressure using a stand-alone radiative transfer model without any convection coupled to it. That’s truly problematic.
The contrived model was then parameterized using Earth data by tuning several driving parameters until the model reproduced reasonably well the observed latitudinal distribution of temperature and albedo on Earth. The authors explicitly acknowledge that the application of this model outside the range of Earth’s parameter values must be done with extreme caution. No wonder why the authors have not attempted to verify their model against Venus data, for example. If this model is being offered as a tool to determine the habitability of extra-solar planets, it would be natural to demonstrate its skills against two extreme environments such as Venus and Mars. But the authors did not do it, and probably for a good reason …
Looking at the output shown on Figures 3 and 4, I think this model drift significantly from reality once the input parameters go outside Earth’s values. The model appears to underestimate the surface temperature for stellar irradiances that are much smaller than Earth’s, while severely overestimating it for irradiances approaching that of Venus. This means that the model suitability to quantifying Habitable Zones is seriously in question.
In conclusion, it is encouraging to see someone really trying to quantify the effect of atmospheric pressure on mean planetary surface temperatures, but it’s disappointing to realize that the authors remained crippled in their thinking by the prevailing Greenhouse Theory, which forced them to adopt a completely backward and unphysical approach to the problem.
**Stephen Wilde says:
May 9, 2013 at 10:04 am
gbaikie says:
“I think if you double Earth’s atmosphere, double the oxygen, nitrogen, argon, and even the CO2,
earth would have a lower average temperature.”
The more mass in the atmosphere the higher the system energy content becomes and the higher the average surface temperature. **
But at the surface the sun will be dimmer.
The reason this world is 15 C is due to large and warm region of the tropics.
And less solar energy will reach the surface of the tropics and it will be cooler as
a result.
The UK may or may not be cooler. It doesn’t get much sunlight as it is, and would get
much less sunlight when it’s not cloudy- it could have warmer winters and night.
But as said what largely determines global temperature is the tropics and tropics is
warm because the sun is largely high in the sky. If there is twice atmosphere the sun
has to travel more of it and it’s energy is lessen.
So tropics should be cooler, and therefore one has a cooler planet.
Though maybe you would not have ice caps, and therefore not be in
the current ice box climate.
“Likewise, if one increases the strength of the gravitational field which compresses the atmosphere thereby increasing density which allows it to retain solar energy for longer.
Likewise increasing ToA insolation which means that more energy is flowing through at any given moment.”
I think one would increase by a significant the amount sunlight reaching the surface, most dramatically increase sunlight in such areas as UK- when sun at lower angle it would go thru less atmosphere.
And increase convection. And atmosphere has more stored kinetic energy.
More gravity definitely causes warming.
Conversely less gravity causes it to be cooler.
Ned Nikolov says:
“I think I said this several times before on the blogs – the thermodynamic part of climate models is based on the gas law and that’s all good. However, the problem is that, in the solution, the convective heat exchange is always decoupled from radiative transfer in a sense that these two key heat transport mechanisms are NOT solved simultaneously as they occur in reality. The effect of this artificial decoupling is the simulated increase of surface temperature with rising CO2 (i.e. with increasing atmospheric LW emissivity or opacity). This result is unphysical and violates the conservation law … None of the climate scientists I’ve talked to (including Richard Lindzen) appear to be aware of this problem.”
———————————————————————————————————————-
Bingo!
Convective circulation below the tropopause depends on radiative gases. Without radiative energy loss at altitude, convective circulation in the Hadley, Ferrel and Polar cells would shut down. The failed radiative greenhouse hypothesis depends on not modelling the role of radiative gases in atmospheric circulation correctly. A traditional pre AGW hoax description of the role of radiative gases in tropospheric circulation can be found here –
http://www.st-andrews.ac.uk/~dib2/climate/tropics.html
Radiative cool our atmosphere by radiating more than TWICE the energy to space than the net radiative flux into the atmosphere from the surface and the sun. This energy loss at altitude allows tropospheric convective circulation which cools the surface during the day. Near surface temperatures are lower due to the presence of radiative gases. Radiative gases cool our atmosphere at all concentrations above 0.0ppm.
Ned writes “None of the climate scientists I’ve talked to [..] appear to be aware of this problem.”
I also thought this was the case, but information has subsequently come to light that indicates that some on the AGW promoter side knew of the issue and tried to bury it. The first I can find is Pierrehumbert in 1995. Warmist site ScienceOfDoom summarises his bafflegab proposing that initially radiative gases cause cooling but after a mystical typing point that they cause warming here –
Suspicion must also fall on those warmists who tried to destroy the Makarevia 2010 discussion paper. They fought viciously against any suggestion that a rising moist airmass full of the radiative gas H2O could be any more diabatic than a dry airmass.
Thanks Ned: you say: “In their heat diffusion model (Eq. 1, see also the Appendix), pressure is assumed to control the effective heat capacity, the heat diffusion coefficient, and the outgoing long-wave radiation (OLR). Everyone who knows basic thermodynamics will immediately note that these assumptions are physically incorrect.”
Could you expand a bit on why effective heat capacity isn’t affected by pressure please. Air is compressible, and so near surface air will be denser, notwithstanding it’s expansion due to being warmer than higher altitude air. I would have expected denser air to have a higher heat capacity.
Thanks
Yes Rog I wondered on that too, mass of gas increases with pressure because there is more of it, therefore thermal capacity is greater. Different worlds, not the same ones.
AFAIK the bone of contention is that thermal capacity of a gas **all else being equal** does not change with pressure. The term in that field is mol, constant for the test?
Q: what about turbidity?
Is that taken into account or not in transparency?
Making things even more fun this might affect cloud nucleation too and yet clouds are turbid.
As I said before:
“Pressure is a result of mass plus gravity so:
i) Higher pressure from more mass would raise temperature and
ii) Higher pressure from stronger gravity would increase density and reduce energy flow rates to raise temperature.
So, I agree that increased pressure in itself has no direct effect but (indirectly) increased pressure is a result of more mass or more gravity which do both have a warming effect.”
It may be seen as unfortunate that this paper has sought to explain the correlation with planetary atmospheric pressures and temperatures it terms of the hypothetical radiative green house effect. However, all possible mechanisms for the correlation should be explored. I would note that while correlation between earth’s temperature fluctuations and solar activity is observed, a proven mechanism is still elusive.
My early basic experiments into the N&Z hypothesis showed that for non-radiative gases in contact with a matt black target plates equally heated by SW radiation, the test chamber with the higher gas pressure heated faster. I later found the corollary for the mechanism for this was already well accepted in the field of heat sink design for aviation electronics.
Strangely the atmospheric temp/pressure correlation seems to hold for atmospheres in which little SW reaches the planets surface. I suspect the answer is that all atmospheres observed are experiencing vertical circulation.
The original N&Z hypothesis seems to have a fault in that the role of radiative gases in cooling the atmosphere is ignored. Without radiative gases, there would be no convective circulation in our atmosphere and stagnant gases at altitude would super heat due to the absorption of IR and UV such as occurs above our present tropopause. No planet or moon in our solar system has managed to retain a significant atmosphere without radiative gases.
There would still be a circulation with a radiatively inert atmosphere.
The decline in pressure, density and temperature with height would ensure a lapse rate and uneven surface heating would cause convection.
All incoming radiation would be radiated out from the surface because excess incoming energy on the day side would rise higher via convection and then sink on the night side warming adiabatically as it does so thereby returning energy to the night time surface for radiation out to space.
At equilibrium the excess incoming to the surface on the day side would be offset by excess outgoing from the surface on the night side.
I have to add my kudos here. We’re so immersed in this radiative nonsense that we’re compelled to talk about sensitivity in terms of ºC per “doubling of CO2” when apparently CO2 has practically nothing to do with it. Its hard to break old habits.
“… then sink on the night side warming adiabatically ”
But Stephen, you just got the top to be warmer during the day at the beginning, so what do you you imagine would be causing the sinking at night since the top cannot radiatively cool?
This is all well and good but like most people they have completely forgotten about the effects of the solar declinational tides that give rise to the seasonal fluxes of equatorial air masses into the respective summer hemisphere. And the lunar declinational tides in the atmosphere that shove pulses of equatorial warmth and moisture into both hemispheres every 13.8 days from primary and secondary tidal bulges that drive most of the rapid meridional flow surges that produce most of the heat transfer toward the poles.
The atmospheric circulation of Venus is like continually sliding a mixing spoon around just the edge of a bowl of cake mix, where in the earths global circulation the moon is a mix master at full speed sweeping through the middle of the bowl towards the outside fourteen times a rotation of the earth around the sun. The effects are easily tasted in the cake results, and it makes the local weather almost un-forecastable with out considering these effects in the process.
Climate programs try to work with out these continual homogenizations of the global air masses, but they are most of the mechanism for the equator to poles heat transfer, it is the precession of the nodes and the 18.6 year cycle of declinational angle at culmination that drives the hurricanes, severe weather surges, and blocking highs that form from the masses of well homogenized ion free air masses that give rise to droughts, and the confluences of ion rich but opposing polarity clashing air masses that give rise to the heavy monsoonal floods.
But the rest of the above posted argument is valid in the light of these overlooked effects are seen as averaged out in the long run, which if that was true the climate would be very boring indeed.
I suspect that thinking about an atmosphere completely devoid of IR gases is a hopeless quagmire, because …
1) Such systems never exist in reality — there are significant amounts of CO2/H2O/CH4/NH3/O3 in every atmosphere in the solar system.
2) The dynamics of a fluid being heated unevenly on a rotating planet is not the sort of problem you solve just by musing about it.
I suspect that Stephen is correct that there would be circulation up on the sunny side and down on the night side. Gas rising by convection will necessarily create a low pressure system, drawing in air from all around to replace the air rising in the updraft. But I really don’t even want to guess if this will lead to 1000+ mph winds at the surface, or 1000+ mph winds higher up, or perpetual hurricanes or … . There are far to many variable and for to little value to head off onto this tangent for me.
wayne asked:
“But Stephen, you just got the top to be warmer during the day at the beginning, so what do you you imagine would be causing the sinking at night since the top cannot radiatively cool?”
The top isn’t warmer than permitted by the lapse rate. As the warmed air rises KE is replaced by PE and it cools. Then when it descends it converts PE back to KE and it warms.
The rising is caused by uneven surface heating leading to different densities which result in some parcels of air becoming less dense and lighter than adjoining parcels.
As the rising occurs the different densities are maintained because as fast as the lighter parcel rises the new adjoining parcels at the higher levels remain just as much cooler and more dense because of the reducing pressure and density with height.
That is termed adiabatic uplift because it continues without addition of new energy. Once a warmed parcel of air detaches from the ground it will continue rising adiabatically even if the ground beneath it then cools whilst it is still rising.
The rising continues until something puts a stop to it. In practice that is an inversion layer where the lapse rate is reversed so at that point density and temperature equalises so the rising stops. On Earth that is the tropopause.
However, what goes up must displace air higher up in order to take its place so a circulation forms whereby warm, less dense air rises and cold more dense air falls.
That is the source of our high and low pressure systems beneath the tropopause.
In a non rotating world the day side would be a large single low pressure region with rising air and the night side would be a large single high pressure region with descending air.
Where there is rotation then that combines with the coriolis force and the decline of insolation towards the poles to break the high and low pressure cells up and distribute them into permanent climate zones with jet streams between them arranged latitudinally.
Then, if anything seeks to disturb thermal equilibrium, the latitudinal positioning will change in order to retain equilibrium because latitudinal changes alter the rate of energy throughput.
It is all very well knowing physics but to see the truth one needs an understanding of meteorology too.
Richard Holle.
It is quite right that the factors you mention have an effect. However our main concern is longer term climate change such as that from MWP to LIA to date.
tjfolkerts said:
“But I really don’t even want to guess if this will lead to 1000+ mph winds at the surface, or 1000+ mph winds higher up, or perpetual hurricanes or … . There are far too many variable and far too little value to head off onto this tangent for me.”
Don’t be put off by the multitude of variables because it all boils down to a single simple issue in that energy out must equal energy in for an atmosphere to be retained.
The strength of the winds will simply be whatever is necessary to get energy back to the night side surface quickly enough to enable surface radiation from the night time surface to be sufficient to maintain radiative balance at top of atmosphere.
If one then adds GHGs to the mix then they enable an additional radiative window to space directly from the atmosphere and so the winds can be slower.
That was a fundamental point in my article about the adiabatic and diabatic loops.
“far too little value to head off onto this tangent for me.”
I see it as the most important point of all because it shows exactly why and how the system stays stable enough for atmospheres to be common in the universe and why GHGs do not need to have any significant net effect after the negative system response via circulation changes has been taken into account.
Note that my proposition accepts a climate effect from GHGs and therefore is consistent with the science of Arrhenius and basic AGW theory.because GHGs do result in a changed circulation and climate zone shifts.
It is just that since the entire mass of the atmosphere is involved and since solar and oceanic effects are so large the GHG effect is so miniscule as to be indistinguishable from zero.
Konrad said :-
Strangely the atmospheric temp/pressure correlation seems to hold for atmospheres in which little SW reaches the planets surface. I suspect the answer is that all atmospheres observed are experiencing vertical circulation.
So presumably including heat transport down in some areas / situations and heat transport up in others. Or is all heat transport downwards purely radiative ? Surely not.
Tim and Stephen,
The established pre AGW hoax science of tropospheric convective circulation is here –
http://www.st-andrews.ac.uk/~dib2/climate/tropics.html
Tim is trying to defend the the radiative warming hypothesis. Stephen is trying to defend a radiative neutral hypothesis. But you are both invoking unproven atmospheric circulation systems to support your hypothesis.
I on the other hand have shown by empirical experiment that energy loss at altitude is critical for convective circulation below the tropopause.
None of the mechanisms you have proposed for atmospheric circulation can come close to matching the power of radiative gases. These gases are emitting TWICE as much IR to space than the net flux of radiative energy into the atmosphere. IR emission to space from the upper troposphere is almost equal to all the energy entering the atmosphere from surface conduction, surface IR and solar IR/SW/UV combined.
The green house gases in our atmosphere are N2 and O2. Radiative gases, primarily H2O, are the broken panes at the top of the greenhouse.
Stephen, look at the conditions above the tropopause. Is your vertical circulation driven by planetary rotation in evidence? No. Only the layer of the atmosphere with high concentrations of radiative gases is exhibiting strong vertical circulation. Planetary rotation and Coriolis force do have an effect on convective circulation. Because of these forces, tropospheric convective circulation breaks into three cells north and south of the equator. If planetary rotation were slower, a single Hadley cell would stretch from equator to pole. There is no way out, strong vertical tropospheric circulation depends on radiative energy loss at altitude.
Tim, this won’t wash – “I suspect that thinking about an atmosphere completely devoid of IR gases is a hopeless quagmire, because … “
You are just repeating Joel Shores attempted deflection. It is not a hopeless quagmire, it’s very simple. Without radiative gases most of our atmosphere would boil off into space. Increasing concentrations from 0.0ppm cool the atmosphere and drive convective circulation. In assessing the impact of adding radiative gases to the atmosphere the low concentration condition must be considered. It is completely illogical not to do so.
Ray Pierrehumbert clearly understood what the problem was before 1995. sadly I think it speaks to his character that he chose to try and bury it to defend the AGW cause. I wanted to believe that AGW was just an unfortunate scientific mistake. This no longer appears to be the case. This is the age of the Internet. The corpse of AGW cannot be reanimated, nor can it be hidden.
Konrad.
Above the tropopause ozone warmed directly by the sun creates a temperature inversion which puts an effective lid on tropospheric convection.
If there were no ozone there would be no inversion and convection would go higher.
For convection from a surface only a temperature decline with height (pressure induced) and uneven surface heating would be required.
Radiative gases not necessary.
Planetary rotation only breaks the circulation up into smaller units of high and low pressure cells.
Even in the stratosphere there is a circulation.
In Mesosphere and Thermosphere I would guess there would still be a weak circulation but due to the thinness of the air at such heights we are currently unable to observe it.
Wherever there is uneven heating and a temperature change with height a circulation will develop.
“energy loss at altitude is critical for convective circulation below the tropopause. ”
It is true that higher levels need to be colder but the energy doesn’t need to have been lost by radiation. Conversion of KE to PE with altitude does the job without specific radiative loss because only KE registers as heat.
Energy is lost by radiation from GHGs in the troposphere but that reduces the need for so much radiative loss from the surface on the night side so one gets a slower overall circulation with less energy needing to be returned to the surface on the night side.
If the circulation stayed just as vigorous after the addition of GHGs to a non GHG atmosphere then the surface would radiate just as much as before AND the GHGs would ALSO radiate direct to space and there would be more energy going out than coming in.
That can’t happen so the circulation MUST reconfigure to prevent it.
Konrad said: I on the other hand have shown by empirical experiment that energy loss at altitude is critical for convective circulation below the tropopause.
Wouldn’t your experiment have to include a larger surface w/ uneven heating to that surface (more like planetary heating). in order to prove the above? Or is there a more elaborate experiment you’ve performed that I’m missing?
If not, I have to agree with Stephen on this one. Adiabatic processes would be sufficient to cause circulation below the tropopause.
Thanks for the interesting discussion. 🙂
“Radiative gases not necessary.”
Sorry, that’s not true Stephen. You need to take some sailplane lessons and you might find your “convection loops”, “adiabatic and diabatic loops” are very shallow on the average, at best (except in big storms) only to about 4000-6000 ft and only when warm, just to the cloud base. That is the mixing layer. You seem to be imagining the entire troposphere does this, always, and during the day. Wish it was true, flying a sailplane would be so simple. You seem to be forgetting the Poisson’s equation and equivalent potential temperature. It is that which qunches you loops with height, not just the raw temperatures.
wayne, there is lots of complexity within the troposphere let alone the entire atmosphere just as you describe but the net overall effects are as I say.
In general, overall, warm less dense air rises to the tropopause and falls to the surface as cold dense air.
Your thermals from surface to cloud base are only shallow disturbances often constrained by local inversion layers.
Think in terms of high and low pressure cells on large scales rather than local thermals.
On a local scale wayne, grander scale, see Hadley cells and so on.
Eric Barnes says:
May 11, 2013 at 4:47 pm
—————————————————————————————-
Eric,
Experiments 1 to 5 are described here –
These have been designed so other blog readers can build and run them for themselves.
The most relevant experiment is Experiment 4. This does not involve IR radiation, but rather runs on convection and conduction. To get the best results the gas columns should be built as tall as possible to reduce scale effects of gas conduction.
Here is a diagram of the set up –
Here is what is happening inside the gas columns –
http://tinypic.com/r/zmghtu/6
Here is a version I built which allows the height of energy loss to be varied in the one column –
http://tinypic.com/r/15n0xuf/6
In Experiment 4, the gas column that runs hotter has both cooling and heating at the “surface”. The column that runs cooler has heating at the surface and cooling at altitude.
Essentially the AGW hypothesis fails for an atmosphere in which the gases are free to move. The AGW hypothesis depends on ignoring the role of radiative gases in driving vertical circulation and the cooling effect of this at the surface. Radiative cooling at altitude drives convective circulation in the troposphere. There is no other mechanism in our atmosphere with the same power to do this.
Dr. Spencer has thrown down the gauntlet to “slayers” at his blog. While I do not support their arguments, I will try to challenge his radiative greenhouse hypothesis. However I doubt Dr. Spencer will rise to debate. I suspect Dr. Spencer is a big chicken that uses the “Slayers” as a excuse not to consider other challenges to his hypothesis.
Sorry, my bad. I keep thinking we are speaking of long term averaged climate and it appears we are clearly not. That explains why little is making any sense. Better if I just shift back to a weather and energy redistribution mindset to get in step.
” Radiative cooling at altitude drives convective circulation in the troposphere. There is no other mechanism in our atmosphere with the same power to do this.”
Conversion of KE to PE as air rises has the power to do it.
The reduction of density with height involves the molecules moving further apart and when that happens KE turns to PE so that the gas cools.
Remember that gas at any height contains the same total energy as it did at the surface but as one goes up PE replaces KE which causes the temperature fall.
A gas molecule at ToA contains no less total energy but it is almost 100% PE and it is at the temperature of space.
It never quite becomes 100% PE because the temperature of space is slightly above absolute zero.
“I keep thinking we are speaking of long term averaged climate and it appears we are clearly not”
We are, but your reference to sailplanes relates to local short term weather in the form of small scale thermals of limited height.
“I suspect Dr. Spencer is a big chicken that uses the “Slayers” as a excuse not to consider other challenges to his hypothesis.”
That seems so.
He has failed to comment on my ‘non slayer’ objections to his initial description.
Stephen,
KE to PE conversion is not a diabatic process. For an air mass to lose buoyancy diabatic energy loss is required. The role of radiative gases in convective circulation was established science before the AGW hoax, as seen here –
http://www.st-andrews.ac.uk/~dib2/climate/tropics.html
You are trying to evoke strong vertical troposphereic circulation without diabatic processes. It is interesting to note that Joel Shore, Nick Stokes and Tim Folkerts are all now trying the same thing.
Stephen Wilde says:
May 12, 2013 at 7:53 am
———————————————————————–
Anthony and Dr. Spencer do seem to be being very badly behaved in their defence of the radiative GHE hypothesis. I am beginning to suspect they have worked it out. Some sceptics are going to be more embarrassed than AGW believers.
Konrad.
Energy from the sun causes the initial lift off. That is diabatic.
Once the parcel is detached from the surface no more energy is added but it keeps rising. That is adiabatic.
Konrad.
I don’t see anything in your link that contradicts what I say.
It emphasises the effect of water vapour and radiation from the atmosphere but even if one strips that out there will still be a convective circulation caused by uneven surface heating and a change in temperature with height.
Konrad said:
“Anthony and Dr. Spencer do seem to be being very badly behaved in their defence of the radiative GHE hypothesis.”
Agreed. While it’s annoying that Roy doesn’t reply he doesn’t filter the question either as some would.
I have a suspicion he is working on a new model/analysis currently and is refraining til he’s tied up all loose ends.
Thanks for the link to experiment 4.
I agree with Stephen as well in that I don’t see how it incorporates adiabatic cooling/heating.
Konrad 4:24am, Stephen 7:53am:
Dr. Spencer is on the right track to ask for a simple, basic energy balance model for planetary surface Tavg. from critics that does better than the existing text book science, analysis and experiment.
The existing text book version computes Earth and Venus et. al. near surface atm. spatial and temporal Tavg. within about 1 Kelvin out of measured ~288K and ~732K. This result is from input of LTE balanced experimentally measured planetary temporal and spatial avg.d net insolation, L&O surface emissivity, and surface to TOA atm. emissivity/absorption. This remote sensing is applicable to the exoplanets and this science is being applied for exciting remote atm. discoveries.
As yet, neither Konrad nor Stephen et. al. have met Dr. Spencer’s challenge to do as well or better and show their detail work. The critics of the text book methods are just not up to meeting his challenge or able to do better basic science to date.
But it is sort of fun watching the emotion of the critics that try and fail to meet the challenge. Has been very informative for me at least.
NB1: Stephen cannot meet Dr. Spencer’s Tavg. computational challenge considering just atm. mass, insolation and gravity. Needs to add atm. emissivity/absorption to his repertoire (radiative physics) and precise calculations supporting imprecise prose.
NB2: Konrad’s experiments fail to meet the challenge b/c of imprecise energy flux in/out lab measurement work coupled with not completely measuring the temporal and spatial temperature fields (Konrad can’t run back to and hide behind 1 lab temperature reading).
So I go with the text book science. Experiencing interesting fun & learning while adding to basic text book science is more rewarding and can be beneficially applied in my view.
240 in and 240 out at ToA.
150 from surface to atmosphere via non radiative means.
150 from atmosphere to surface by non radiative means.
Books balanced.
The balancing energy is that which is converted from KE to PE and back again by adiabatic uplift and descent.
The temperature rise is determined by how long KE remains in PE form before it is returned to the surface and that is determined by the mass of the entire atmosphere.
Roy Spencer’s request dealt with.
Stephen 5:03pm – Your post doesn’t compute and show the work for temporal and spatial near surface Tavg. approximating measurements. Dr. Spencer’s exact challenge not yet met by Stephen.
BTW, there isn’t 240 in at TOA.
BTW, there isn’t 240 in at TOA.
Substitute correct figure.
As I just replied to Joel Shore:
Radiation is a consequence not a cause.
Lets look at the non GHG atmosphere as a ‘pure’ example.
At the formation of the planet 240 comes in but 150 gets diverted into the atmosphere by non radiative processes.
The surface initially radiates at 90 but after a while the 150 removed gets returned to the surface by non radiative processes and new energy is still coming in at 240 so you get a surface temperature that should radiate at 390 but the atmosphere is still taking 150 by non radiative means so ToA still only allows 240 out.
From that point on, 240 comes in and 240 goes out but 150 keeps getting recirculated between surface and atmosphere by non radiative means.
What is the problem with that?
For an atmosphere with GHGs the numbers change a bit from the non GHG scenario but the principle still applies.
Stephen 5:49pm: “What is the problem with that?”
The compliance problem is no where do you compute Tavg. from planetary energy gain and loss terms showing/citing the work from where you derived energy gain and loss at least as well and peferably better than Dr. Spencer shows along with the modern text books.
BTW there was ~341.3 W/m^2 in at earth TOA (or moon surface) from March 2000 to May 2004. Proper atm. science supports your last sentence will be shown ~true once you show the work derived from modern text books.
No need to compute Tavg even if it could be ascertained.
What matters is radiative balance at ToA.
To achieve that one only needs to describe the flows in qualitative terms.
Modern text books simply speculate to fill in the gaps in their theorising.
“BTW there was ~341.3 W/m^2 in at earth TOA (or moon surface) from March 2000 to May 2004. ”
I was using Joel Shores own numbers in an attempt to illustrate a point to him.
If they were incorrect it doesn’t matter for the illustration.
Stephen 6:24pm, 7:19pm: Text book planetary Tavg. is computed from radiative transfer theory thermo 1st principles to 1K off from earth’s thermometer network measured as I’ve shown you previously.
There is a need to compute planetary Tavg. from your theories of mass, insolation, and gravity in order to “put up” for Dr. Spencer’s challenge. Until you show that calculation using only mass, insolation and gravity as input, you have not “put up” or met his challenge.
Joel’s numbers would have been net of albedo (gross in vs. net in); Joel has met the challenge. So far you have not, but keep trying since your attempts are entertaining. You will find albedo and atm. emissivity are needed in Dr. Spencer’s surface “delta Z” layer Tavg. calculation starting with net solar 161 W/m^2 (yellow arrow gross 341.3 W/m^2 TFK09) in from ToA as Dr. Spencer’s challenge indicates – unless and if you can “put up”.
Eric Barnes says:
May 12, 2013 at 3:41 pm
——————————————————-
Eric,
the experiment covers only convective circulation. It should be noted that strong vertical circulation does not develop in the gas column with both heating and cooling at the base.
Adiabatic heating and cooling do not represent energy lost or gained by rising and descending air masses. Adiabatic processes are a function of vertical circulation, but they play no role in driving it. Vertical circulation is driven by changes in buoyancy, requiring diabatic processes. Energy must enter, leave or be released within an airmass to change it’s buoyancy.
This section from the link I gave above explains the pre AGW hoax science of the role of radiative gases in convective circulation –
“Air convected to the top of the troposphere in the ITCZ has a very high potential temperature, due to latent heat release during ascent in hot towers. Air spreading out at higher levels also tends to have low relative humidity, because of moisture losses by precipitation. As this dry upper air drifts polewards, its potential temperature gradually falls due to longwave radiative losses to space (this is a diabatic process, involving exchanges of energy between the air mass and its environment). Decreasing potential temperature leads to an increase in density, upsetting the hydrostatic balance and initiating subsidence. The subsiding air warms (as pressure increases towards lower levels), further lowering the relative humidity and maintaining clear-sky conditions. However, although the subsiding air warms, it does not do so at the dry adiabatic lapse rate. Continuing losses of longwave radiation (radiative cooling) means that the air warms at less than the dry adiabatic lapse rate (i.e. some of the adiabatic warming is offset by diabatic cooling).”
Trick says:
May 12, 2013 at 8:53 pm
————————————————-
Up to your old tricks? 😉
Some of the debate is indeed becoming quite entertaining. Particularly Tim, Joel and Nick trying to invent mysterious atmospheric circulation systems that don’t depend on radiative gases.
Trick, as you like studying text books, could you please give me a direct, clear YES or NO answer to the following question –
“Are radiative gases critical to tropospheric convective circulation?”
I agree with Konrad, radiatively active gases cool, while the N2 and O2 are the GHGs.
“I agree with Konrad, radiatively active gases cool, while the N2 and O2 are the GHGs”
I also agree with Konrad to that extent but I think that, either way, circulation adjustments restore the ideal lapse rate set by mass etc.
I still disagree that there would be no convective circulation without GHGs because the density reduction with height provides the necessary cooling to allow convection even with no radiative cooling at altitude.
Stephen Wilde says:
May 13, 2013 at 11:16 am
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Edim is essentially correct. N2 and O2 are the “greenhouse gases” in our atmosphere, radiative gases are the broken panes in the top of the greenhouse.
Stephen, adiabatic cooling of ascending air masses is matched by adiabatic heating of descending air masses. Adiabatic processes have no effect on the buoyancy changes that drive strong vertical circulation below the tropopause. IR emissions to space from the upper atmosphere emit more than twice the net radiative flux entering the atmosphere from both the sun and the surface. This is what is driving convective circulation below the tropopause. No other proposed mechanism has this power.
Over at Dr. Spencers site, Nick Stokes is also trying to invoke a mysterious mechanism for strong vertical circulation in the troposphere in the absence of radiative gases. I am calling it “Stokesian Circulation”. I believe the primary mechanism is groups of panicked climate scientists standing at the surface engaged in frantic hand waving trying to drive mega-tonnes of gas in a vertical circulation loop 15 kilometres high.
Without radiative energy loss at altitude, convective circulation shuts down. IR, SW and UV intercepted by N2 and O2 would then cause super heating in the upper atmosphere, just as in the poorly radiative measosphere. Most of our atmosphere would then boil off into space. The bottom line is that radiative gases mean that no ones breathing privileges need be revoked.
Come to the dark side Stephen, we have cookies. Asking warmists to give a yes or no answer to the question –
“Are radiative gases critical to convective circulation below the tropopause”
– is too much fun. It’s like having a silver plated cage full of vampires and a super-soaker full of holy water 😉
Konrad 7:04am: ““Are radiative gases critical to tropospheric convective circulation? Yes or no.”
No.
See top post, the greenhouse panic is over, while the global spatial and temporal avg.d satellite measurement of 255K vs. surface thermometer record of 288K remains from March 2000 to May 2004 as ~computed in global avg.d simple, basic text book model by Dr. Spencer.
Expanding on my “no” (in imprecise prose only see the ref.s for precise calculations), modern text books tell us pressure drop and enthalpy difference are critical and common features of real atm.s which absorb lower entropy energy at higher temperatures than they reject higher entropy energy to space. In addition to radiation, convection is defined as a dry process reflecting the diffusive and advective transfer of heat and mass energy. These convective processes play an important role in the energetics of the atm. in vertical energy transport.
I see Konrad has not yet met Dr. Spencer’s challenge to “put up” since I see no quantitative model of planetary global avg.d near surface temperature closer to thermometer measurements “put up” to date from Konrad.
The simple, basic text book case computed by Dr. Spencer stands & is remarkably close to measurements. It even easily computes the cooler near surface Tavg. for an atm. with 0 emissivity in LTE and not the hotter atm. “boil off” erroneously reported in prose only per Konrad. At least, until and if Konrad can show the cutting edge science atm. calculations behind his assertions.
——-
Citations: Bohren 1998 text as always. Also more complex than Dr. Spencer’s simple model & Bohren’s 1st course text , here are two quick access & more modern ref.s if you can absorb atm. “cutting edge science you can dice with” calculations:
Click to access Renno_2008.pdf
Click to access radconveq.pdf
Konrad,thanks for the invitation but I’ve been on the dark side all along and am still there.
I don’t know why the alarmists are in favour of convection without radiative gases because once one accepts it then the entire mass of an atmosphere becomes involved in the greenhouse effect and the influence of CO2 becomes miniscule. Perhaps they just haven’t realised that yet though I have been pointing it out.
Anyway, back to your specific points:
You correctly identify that the presence of GHGs allows radiation out direct from the atmosphere thus adding to the decline in temperature with height that would be present anyway due to the reduction of density with height.
Where you seem to have a problem is envisaging a cooler upper atmosphere even without that boost in radiative output to space from GHGs.
As I see it, the reducing density with height results from the molecules moving further apart the higher they rise. That moving apart converts KE to PE so the temperature must fall.
Meanwhile the air higher up must be forced back to the surface in a circulation so the upper atmosphere will not superheat.
The energy from surface irradiation causes an air parcel to rise and a portion of its energy is converted from KE to PE creating the temperature decline with height, no superheating.
The descending air then converts PE to KE as it falls and warms the surface which then radiates out to space.
As long as what goes up must come down there will be no accumulation of KE at higher levels, it will have gone to PE which does not register as heat.
The mesosphere cools with height so I suspect you meant to refer to the stratosphere or the thermosphere.
The stratosphere is warmed directly by incoming solar energy reacting with ozone molecules and so is an exception to the rule that temperature declines with height.
The thermosphere is again warmed directly by solar shortwave hitting its constituent molecules and so is another exception.
In contrast, both troposphere and mesosphere show the decline of temperature with height because they are not directly affected so much by incoming solar radiation.
For the reason why gas must cool when it rises see here:
http://en.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect
“As a gas expands, the average distance between molecules grows. Because of intermolecular attractive forces (see Van der Waals force), expansion causes an increase in the potential energy of the gas. If no external work is extracted in the process and no heat is transferred, the total energy of the gas remains the same because of the conservation of energy. The increase in potential energy thus implies a decrease in kinetic energy and therefore in temperature.”
It is therefore established science that if a gas parcel rises adiabatically (no heat added or removed) which it does once detached from the surface, then the expansion arising from the reduction of the weight of gases above it must cool the gas as described above.
Some think that the continued rising of a parcel of warmed air relies on more energy constantly being added at the surface (a diabatic process).
In fact, each parcel or bubble of warmed air stops receiving energy from the surface as soon as it loses contact with the surface.
Yet it continues to rise (adiabatically) because the air around it at each new higher level has also been cooled by the reduction of density and by expansion at that new height so the warmed parcel retains its density and temperature differential with the surrounding air and keeps going up adiabatically.
It would rise to ToA unless prevented from doing so by an inversion layer where the rise in temperature with height allows the density and temperature differential to be equalised.
On Earth that happens at the tropopause but only because direct solar heating of ozone reverses the normal lapse rate in that layer.
I hope that helps because, if not, I cannot make it any clearer.
Stephen 2:38pm: It helps. In other words, near surface temperature being controlled by mass, net insolation, miniscule radiative CO2 influence and gravity puts you in violent agreement with modern text books.
That is commendable progress adding your radiative physics key concession regards the top post: “…the greenhouse effect and the influence of CO2 becomes miniscule.” Not a panic.
IIRC in Stephen’s prose, radiation used to be 0 effect & now atm. CO2 influence becomes miniscule.
Cool. So far we’ve survived 400ppm and can still play softball outdoors. The NCAAs will prove it this week. Barring rain, of course, LOL.
Trick,
The effect of CO2 is different from the effect of mass, gravity and insolation because it gets corrected for by a circulation change rather than by a significant change in system energy content or temperature.
I can concede some effect on system energy content and temperature whilst the circulation adjusts to negate it but it cannot have a permanent effect on system energy content and temperature otherwise radiative characteristics of molecules would be represented by a specific term in the Gas Laws.
Instead, the Gas Laws just have a term for molar mass (n) with no mention of the radiative abilities of that mass.
I think you suggested that it might be covered by the term R (the gravitational constant via the specific gravity of a molecule) but gravity works only on mass and has no changed effect if that mass has radiative capability.
I am driven to the conclusion that radiative characteristics simply change V on one side of the Gas Law equation and molar mass per unit of volume (density) on the other side of the equation for a zero effect on T
The expansion of the atmosphere (V) when density is reduced by the presence of GHGs pushes against the the Van der Waals force (the intermolecular attractive force) described above to convert more KE to PE and thereby negate the thermal effect of those radiative characteristics.
Sterphen 4:22pm: “…(CO2) cannot have a permanent effect on system energy content…”
Correct, all added CO2 can do is shift energy already in the system from great height to near surface denser atm.
Correct also, IGL isn’t a complete radiative transfer eqn., it was developed for pressure vessels (& helium balloons big and small) and used economically to design steam locomotives. It has proven useful in atm. remote sensing in the form(s) p=density*R*T (and p=z*density*R*T for non-ideal situations).
Well, it is amazing we can agree discussing some of this. The volume stuff is not very useful in atm. science, have to be careful in drawing conclusions from it – that they agree with radiative, convective, and conductive energy transfer 1st principles. Better to just use those principles in atm. and save the extra checking step that’s required for IGL conclusions on 1st principles of the thermo grandmasters.
They used instruments to calibrate the theory, now we use the theory to calibrate instruments.
BTW, when you quote PE,KE you leave out the effects of the part of atm. enthalpy coming from the PdV term which is where the volume is properly coupled to the atm. parcel science (even the parcel as a whole). So, fun discussion Stephen, thx.
Konrad says: “Some of the debate is indeed becoming quite entertaining. Particularly Tim, Joel and Nick trying to invent mysterious atmospheric circulation systems that don’t depend on radiative gases.”
Konrad, I believe you did an experiment with heating at the bottom on one side, and cooling at the bottom on the other side. In any case, here is a similar experiment with water:
This would be the equivalent of “circulation systems that don’t depend on radiative gases” since all the heating/cooling would be at the bottom — no cooling at the top (eg radiative gases) is required. Clearly the system in the video DOES have convection.
(FWIW, I am convinced that — given enough time — a system with steady heating and cooling only at the bottom would eventually cease to convect. However, the rotation of the earth will ensure that our atmosphere would never come to a steady-state, non-convecting situation.)
Trick said:
“The volume stuff is not very useful in atm. science, ”
That may be where we must continue to disagree.
Volume dictates density at every point in an atmosphere above the surface (but not AT the surface). and so controls the relative proportions of KE (affecting temperature) and PE (not affecting temperature) which in turn affects the actual (as opposed to ideal) lapse rate slope.
That is the real control knob, and volume changes invariably result in a negative system response which successfully eliminates any real world attempt to cause a divergence from the ideal lapse rate set by mass, gravity and insolation alone.
Whilst I disagree with you, your objections help me to refine my narrative.
Trick said:
” all added CO2 can do is shift energy already in the system from great height to near surface denser atm.”
But then it causes an increase in volume and a reduction in density to negate its own thermal effect.
I say it does, you say it doesn’t.
Will have to wait and see 🙂
Would there be a way to measure pressure / density temperatures on Earth. Perhaps an insulated column of respectable height located in an old mineshaft perhaps. What sort of height would be required ?
I know that some small scale experiments have been done, but it seems to me that if some convincing measurements could be taken then we could hopefully narrow down the direction of argument / discussion.
It would be interesting to have two columns, one that impeded circulation and another that didn’t. Oh for a tiny fraction of the money wasted on climate religion. Perhaps once a significant rate of cooling sets in that might free up some research money for proper science instead of religious science.
“a system with steady heating and cooling only at the bottom would eventually cease to convect.”
Steady and ‘uniform’ heating at the bottom.
Unevenness of heating at the surface is essential for a convecting atmosphere atmosphere because the parcels of air will only rise relative to adjoining parcels if there are horizontal temperature and thus density variations.
In practice such perfection is unattainable so there will always be convection over a heated surface with or without radiative gases.
I am intrigued to see warming proponents embracing that issue because it immediately involves the entire mass of a gaseous atmosphere in the greenhouse effect thereby reducing our CO2 emissions to irrelevance.
Additionally one should include our oceans as atmosphere since they are partially transparent to solar shortwave.
That further reduces the significance of GHG variations in the air.
Stephen 6:21pm: “Volume dictates density at every point in an atmosphere above the surface…That is the real control knob.”
As I’ve written before, my defense that V thru PV=nRT is not the complete story at every point (control knob) rests on Tim C.’s weather data from Chilbolton, easily accessible around here. If Stephen’s narrative were true in the science, then Tim’s posted pressure trace would exactly resemble the temperature trace. It does not by inspection (of any weather station data, really) so one can readily determine in PV=nRT that volume is not the control knob negating the thermal effect (or use P=density*R*T).
Parcel weather pressure and temperature vary independent of PV=nRT but consistent with radiative, conductive and convective energy transfer in the local atm. parcel. That parcel has no way of knowing what is happening to V 100miles up, say; it reacts to passing weather in local conditions even in LTE.
If Stephen could add the PdV term to the KE,PE narrative then that would be a step closer to the science of why local parcel weather parameters are as measured.
Remember the space station orbits in the atm. (thermosphere), just how much atm. V is there to be used in Stephen’s calculation V to negate T at every point? Exactly?
Stephen 8:44pm:
“..thereby reducing our CO2 emissions to irrelevance.”
First it was minuscule now it is irrelevance. This shows the weakness of narrative. The science shows non-zero but experimentalists haven’t shown by how much added CO2 is non-zero on near surface global Tavg. I agreed with miniscule not irrelevant, but maybe the real non-zero number is the same for both narratives, dunno yet. Yes, wait and see.
J Martin 7:10pm: There is an ideal solution for a standard atm. column up to near the tropopause p=1013.25 hPa to 264.36 hPa posted around here. That is 7,633.9 kg of standard air in a m^2.
Construction of that sort (properly insulated!) would be expensive but, hey, the NSF funds less rewarding stuff all the time maybe for MORE. Might cost less than CERN.
Alternatively, to get the funding request reduced & approved, study reducing the column height to where ISO9000 instrumentation is capable to make readings with reliable confidence intervals.
For instance the total observed enthalpy measured will vary from theory ideal by 2.0032 vs. 2.0106 * 10^9 J/m^2. Good luck with that, as you reduce height it gets even harder. Plus you have to capture a standard atm. in the wild.
Put some blinking red light construction in there to warn aircraft traffic.
“Tim C.’s weather data from Chilbolton, easily accessible around here. If Stephen’s narrative were true in the science, then Tim’s posted pressure trace would exactly resemble the temperature trace”
No it wouldn’t.
Tim’s trace is for a single location.
My narrative refers to the entire global atmosphere taken as a whole.
My words miniscule and irrelevant were used to point out that even if I were wrong about there being a net zero thermal effect (apart from during periods of transition) other than by way of circulation changes then the AGW narrative would still fail for all practical purposes.
If you accept miniscule then our continuing disagreements don’t really matter and can await events.
Stephen 9:19pm – As I wrote, it doesn’t matter if you use a local parcel or the parcel as a whole (entire global atm.). Total V (whatever it is) does not dictate density at every point in the atm. Tim C.’s weather parameter traces or any other prove it by inspection. Atm. science doesn’t use total V, doesn’t even know earth atm. V, yet the science is reasonably useful. It does use density.
Put up a V calculation if otherwise, show me.
For me, miniscule is agreeable in the science based narrative at 400ppm. IIRC it is around 8,000 ppm CO2 that is no longer miniscule for we air breathers. Dunno the dangerous changeover point.
Trick says:
May 13, 2013 at 2:29 pm
cutting edge science,/i>
http://derecho.math.uwm.edu/classes/TropMet/radconveq.pdf.
The paper makes these important and correct statements about the radiative model, convection and H2O:
Several problems exist with this profile:[the vertical profile of temperature resulting from radiative equilibrium ] the temperature is too warm near the surface, too cold near the tropopause, and decays too rapidly in the troposphere.
1 That is, a radiation only model cannot calculate correctly the lapse rate.
the dry adiabatic lapse rate is equal to 9.8 K km-1and can be derived using the first law of thermodynamics.
2 The lapse rate can be derived and correctly calculated from the thermodynamics of convection,
As before, principles of thermodynamics can be used to obtain a moist adiabatic lapse rate, one
in which the latent heating due to phase changes of water is inherently accounted for in its formulation.
3 The lapse rate can be altered by latent heat of H20, water. The alteration can be calculated
The currently popular approach, as in the reference, is to start with a pure radiation model and then add convection and H2O as a correction. Radiative-moist convective equilibrium.
However 2 above shows that a moist convective theory without radiation is sufficient to explain lapse rate.
The biggest and most stable temperature profile in the atmosphere.
Trick says:
May 13, 2013 at 2:29 pm
Konrad 7:04am: ““Are radiative gases critical to tropospheric convective circulation? Yes or no.”
“No”
—————————————————————————-
Thank you for your direct answer.
tjfolkerts says:
May 13, 2013 at 6:10 pm
——————————————
Tim,
what is being demonstrated by that experiment is a horizontal circulation and entrainment. This is also happening in the lower section of gas column 2 in Experiment 4. To see the difference between cooling at the base compared to cooling at the top of a liquid column, you would need a far deeper column. For a gas column, I have found 1m to be sufficient. The taller you build the experiment, the more dramatic the results. Note that I include horizontal circulation in the non-radiative panel of this diagram – http://i45.tinypic.com/29koww6.jpg
Conductive cooling of air in contact with the surface is not effective enough to generate strong vertical circulation over 15 kilometers. Experiment 5 shows that the surface is ineffective at cooling the atmosphere. Gravity creates a bias, holding cool air against the night surface, minimising conductive flux. This limits cooling of the atmosphere by the surface to the speed of gas conduction. The surface is however very effective at conductively heating the atmosphere. Gravity crates a bias, holding cool air against the day surface, maximising conductive flux. This energy is then moved by up by convection, resulting in greater energy transport into the atmosphere than gas conduction alone.
You say –
“However, the rotation of the earth will ensure that our atmosphere would never come to a steady-state, non-convecting situation”
The stratosphere is in conductive contact with the tropopause and subject to the same planetary rotation, yet strong vertical circulation is not observed. Tim, no one has yet offered a strong vertical circulation method that has the power to replace tropospheric convective circulation in the absence of radiative gases.
Stephen Wilde says:
May 13, 2013 at 2:38 pm
“I don’t know why the alarmists are in favour of convection without radiative gases..”
———————————————————————————————————-
Stephen,
The answer is because they know that they have made a HUGE mistake. It does not just mean that AGW is less than previously thought. It means that AGW is a physical impossibility. AGW believers need strong vertical circulation in the absence of radiative gases for the AGW hypothesis to survive.
Ned Nikolov gets it –
“I think I said this several times before on the blogs – the thermodynamic part of climate models is based on the gas law and that’s all good. However, the problem is that, in the solution, the convective heat exchange is always decoupled from radiative transfer in a sense that these two key heat transport mechanisms are NOT solved simultaneously as they occur in reality. The effect of this artificial decoupling is the simulated increase of surface temperature with rising CO2 (i.e. with increasing atmospheric LW emissivity or opacity).”
Ned is right, this is exactly what climate scientists have done. In calculating that the atmosphere would be colder without radiative gases they have assumed continued vertical circulation and solved for radiative flux only. However the current mechanism for vertical circulation in the troposphere depends on radiative gases. Without this circulation our atmosphere would heat dramatically. So dramatically that the radiative flux between the surface and atmosphere becomes totally irrelevant.
Radiative gases only accelerate cooling by providing an additional radiative window to space thereby reducing the need for a more vigorous convective heat exchange.
Without them there is still convection but it needs to be more vigorous in order to return energy to the surface fast enough for surface radiation to effect radiative balance at ToA.
Radiative transfer and convective heat transport are coupled as Ned says (and as I said long ago) but that is a two way process.
More of one needs less of the other and vice versa.
AGW supporters seem to need strong vertical circulation via their positive feedback from water vapour scenario but don’t realise that such strong vertical circulation is a negative feedback rather than a positive one.
Nor do they realise that a vertical circulation without GHGs means that the entire mass of the atmosphere is involved in the greenhouse effect which relegates GHGs to insignificance even if increased vertical energy transport were not a complete negation of the effect of GHGs.
I can get Trick to accept the insignificance of any residual warming effect from GHGs but I can’t get him to accept that in the end it is zero.
I don’t mind because either way AGW as a significant climate forcing element is a fiction.
“The stratosphere is in conductive contact with the tropopause and subject to the same planetary rotation, yet strong vertical circulation is not observed.”
That is because of the low density and the absence of a hot surface at its base..There is still a large slow circulation known as the Brewer-Dobson circulation.
I suspect circulations in Mesosphere and Thermosphere too but too weak and slow for us to have discerned them so far.
Trick said:
” Atm. science doesn’t use total V, doesn’t even know earth atm. V,”
Then how am I supposed to rectify that omission ?
Konrad says:
May 14, 2013 at 4:42 am
Quoting Ned Nickolov
However, the problem [ with climate models ] is that, in the solution the convective heat exchange is always decoupled from radiative transfer in a sense that these two key heat transport mechanisms are NOT solved simultaneously as they occur in reality.
that is
Convective heat exchange and radiative transfer occur at the same time. so they should be treated mathematically like simultaneous equations. That is coupled.
I don’t agree I see convection and radiation as occurring at the same time but not coupled.
Kirchoff’s Law of Conservation of Radiation can be applied at TOA
1st Law of Thermodynamics can be applied to kinetic and potential energy of matter within the atmosphere
Stephen 7:54am: Nice humor, I like it.
But goes both ways, if the infamous they can’t compute earth’s atm. parcel or parcel as a whole V neither can you so it is just not useful to either side. Can’t be rectified nor is it needed to be rectified.
What IS useful is the atm. parcel enthalpy (H) as the internal energy (PE+KE) plus the external work done on parcel’s environment (P*V) – so far you have learned the PE+KE = 1st law constant balance narrative pretty well.
To correctly add the change in V to your narrative you will need to study up on the change in parcel’s external work d(P*V) or PdV and VdP terms performed by a parcel or parcel as a whole which so far are lacking in your narrative. You resort to total V and total dV which is of no use, neither you nor the dreaded climate scientists can calculate atm. system V or total dV in practice.
Hint1: Think about what happens to the PdV term in constant volume applications and the VdP term in constant pressure applications.
Hint2: The increase in enthalpy d(PE+KE+P*V) of a homogeneous parcel is equal to the added heat into that parcel in the relevant diabatic process (can be idealized as constant pressure or constant volume).
Those thoughts ought to attract some narrative improvement interest. But it will take some d(Stephen*narrative) hard work.
NB1: In Bohren’s 1998 text, he starts out with a discussion of avoiding differential calculus at all cost but in thermo work esp. in atm.s we are always talking about change. Dang. Bohren concedes some differential math is just unavoidable as in this post.
“I don’t agree I see convection and radiation as occurring at the same time but not coupled.”
There would be lagging effects, is that what you mean
Trick.
I think the basic Gas Laws aligned with the Joule Thomson Effect tell us what happens clearly enough.
Expanded gases in an adiabatic environment cool because the expansion does work by pushing against the intramolecular attraction between molecules and thereby converts KE to PE.
Even in a diabatic environment such as where GHGs absorb longwave coming up from the ground the resulting expansion of the local air parcel containing the GHGs will therefore use up the extra energy in the cooling process.
If you think there is some KE (as opposed to more PE) left over after the expansion has taken place then that is for you to prove.
Stephen 3:33pm: “Expanded gases in an adiabatic environment cool…converts KE to PE..” AND parcels and parcel as a whole cool by expanding the V in the PdV term. This should be the meat and potatoes of your narrative in which you omit the meat. Was proven even in the text books you used long ago.
There is no adiabatic environment in nature, so the solutions are inexact even when the meat is in your calculation. PdV term is really a big factor in your narrative Stephen. Can’t be approximated by PdV = 0 as parcel expansion is not constant volume by definition, the parcel’s heat gained/lost is governed by PE+KE PLUS the PdV and VdP terms which can’t be ignored or Stephen will arrive at incorrect & indefensible conclusions.
I posted how much the correct science shows the standard atm. enthalpy changes between real and ideal in a m^2 column up to near the tropopause above 5/13 8:57pm, your narrative containing only KE+PE in a gravity field will not match either and that enables you to draw incorrect conclusions using total dV.
Trick.
You need to translate that for me since I can’t extract your point.
My narrative includes variation in d which arises from a change in V which is caused by decreasing P with height which results in conversion of KE to PE in the Joule Thomson Effect.
I don’t see what you think is missing.
Stephen 4:59pm – Variation in d?
d as I use and is accepted as the infinitesimal change differential operator. You get the KE+PE change in internal work resulting from the gravity field; you miss the change in external work done by pressure and volume changes to/from the parcel being examined. The heat transfer from/to the parcel is the sum of changes in both KE+PE PLUS external work i.e. the change in enthalpy of the parcel is equal its heat change.
The entropy is then max. when there is no potential for the parcel heat to perform useful work. Enthalpy and entropy are the key 1st principle ingredients (the meat and potatoes, and green beans).
******
Stephen 3:23pm, Roger 1:23pm: The correct term you are looking for is not lag but superposition.
Radiative, convective and conductive heat transfers are independent processes that can be superposed in a homogeneous system. This is the science that allows the heat balance eqn. 1st principles with radiation theoretically turned off, though Konrad is opposed to that accepted notion above. He has the difficult task to “put up” calculations 1st principles allowing his proposed improved notion or hypothesis presented to be generally accepted.
The best way I can see for Konrad to do so is accept Dr. Spencer’s challenge and “put up” a better basic earth system temporal and spatial avg.d heat eqn. balance calculation than the spreadsheet Dr. Spencer posted that agrees with thermometers & satellites March 2000 to May 2004 and can show better calculations for what would be predicted with no theoretical atm. radiative heat transfer.
This theoretical switch off of radiative transfer allows calculations to prove the hypotheses of whether near surface Tavg. would experience cooling or heating due to radiative heat transfer working/not working in the earth, atm., and sun system heat balance eqn.
Discussing all this with accurate science supports the top post: the near term panic is over. The near surface Tavg. change from increased CO2 ppm is miniscule so far, the system can live with it by inspection. Wait and see if correct long term. Like Keynes said IIRC: “In the long run we’re all dead anyway.” We might as well be right 1st. It is a good challenge getting “cutting edge science you can dice with” right.
Trick.
I assumed you were using d for density.
I can accept that there will be some leakage of energy into or out of an adiabatic process in the real world and it sounds as though that is what you mean by d but you accept that it is infinitesimal.
If all you are saying is that I am wrong just because of such leakage then I have to reject your proposition.
Leakage in is likely to roughly equal leakage out where the adiabatic loop is circular so for all intents and purposes it can be ignored.
I think you are just scrabbling around for any trivial detail so as to save face.
Obfuscation:
“to make obscure or unclear: to obfuscate a problem with extraneous information”
Perhaps we should rename it “Trickfuscation”.
Stephen 6:22pm: Real science sometimes seems so, but in this case no scrabbling. I do appreciate the humor.
The KE+PE is internal energy by the gravity field, there is also independant energy expended on the external surroundings in the expansion of the parcel. No obfuscation; in all the basic text books. Heat flow is complicated, gas enthalpy is not easy. The main reason for this discussion is you can’t just lay off surface T change on the atm. expansion and contraction for nil effect.
“there is also independant energy expended on the external surroundings in the expansion of the parcel. ”
You must be rattled since you haven’t read my post properly before responding.
The adiabatic loop is circular.
What goes up must come down.
Independent energy expended on the external surroundings during expansion is offset by independent energy absorbed from the external surroundings during contraction.
Trickfuscation.
Stepehn 6:57: No, this text book stuff is what you miss by not being able to read the modern atm. texts, obviously.
The loop is not adiabatic. The temperature near surface is affected by additional infrared active gas in the denser atm. by radiative heat transfer to KE. In past posts you have written that the atm. total V simply adjusts exactly to offset the avg.d near surface temperature variation. This is incorrect conclusion based on you obviously not being able to include the external work term(s) in your narrative. It is minuscule, but non-zero, the near surface temperature is affected by the external energy term of gas enthalpy in addition to the effects of KE+PE.
This results in Stephenfuscation as I am just pointing out text book science to Stephen, who I often forget will not even get that dT is not density*Temperature but an infinitesimal change in T, which come to think of it, explains some of your past confused responses.
The adiabatic loop is circular.
What goes up must come down.
Independent energy expended on the external surroundings during expansion (rising) is offset by independent energy absorbed from the external surroundings during contraction (falling).
Once a warmed parcel of air lifts off the surface the continuing rise is adiabatic – standard meteorology.
Stephen 10:39pm – Yes, it is a standard, an approx. standard. The near surface global avg. temperature can increase due to added CO2 (or any infrared active gas) regardless of any total change in atm. V (dV in math terms) – of the atm. parcel as a whole you purport. I am trying to show you why science agrees, resistance is futile.
Any potential increase in near surface temperature (you don’t say surface temperature) simply results in a circulation change.
The CO2 provides an additional radiative window to space not provided by non radiative gases.so uplift slows down as does descent so as to ensure that ToA radiative balance is maintained.
Interesting that you refer to near surface temperature only.
I have been saying that only the surface temperature stays the same because the additional energy held by GHGs stays off the surface and provokes circulation changes in the air instead of raising surface temperature.
Either or both of atmospheric volume or the lapse rate slope must change in order to keep surface temperature stable.
That can involve changes in the near surface temperature but they would still be miniscule from CO2 alone.
Remember too that surface temperatures on Earth are tightly tied to ocean surface temperatures which is another stabilising effect.
Increased evaporation from the oceans helps to reduce warming of the air and restore ToA balance.
You still haven’t acknowledged or contradicted the fact that:
“Independent energy expended on the external surroundings during expansion (rising) is offset by independent energy absorbed from the external surroundings during contraction (falling).”
which seems to dispose of your use of the d term.
Stephen 11:18pm:
My reference to near surface temperature comes from where the thermometers are suspended in the atm. for the 288K global Tavg. for comparison to the satellite measured global 255K.
“ Either or both of atmospheric volume or the lapse rate slope must change in order to keep surface temperature stable.”
No, geez, I just explained how to use volume correctly in gas enthalpy physics & math. Study up Stephen. As for the exact lapse rate slope, this is set by the pressure drop (Poisson eqn. w/no adiabatic parcel assumptions), or the easy & approx. lapse rate slope set by g/Cp if make a parcel adiabatic during small displacement. The intercept of the slope at surface is the near surface temperature calculated by heat eqn. balance of net insolation, L&O surface emissivity and atm. emissivity.
This intercept calculation is as Dr. Spencer shows in his spreadsheet which you have not as yet bested with your hypothesized concept of surface temperature set by mass, insolation and gravity so HIS stands. The intercept achieves stability at 288.23K with his input assumptions.
Change his assumptions to a theoretical atm. w/o radiative transfer enabled (0 atm. emissivity i.e. IR transparent atm.) with convective, conductive heat transfer operating just fine, find his spreadsheet computes the intercept near surface temperature would be 256.12K at stable point, no atm. boil off found as Konrad hypothesizes but has not “put up” calculations showing that yet AFAIK.
Since the lapse rate slope intercept at surface is set in part by atm. emissivity in Dr. Spencer’s spreadsheet, you can easily play around and see how much a variation in global atm. emissivity affects near surface temperature in the real world since all his input data are measured. This is exactly how any added infrared active gas acts on surface temperature. If Dr. Spencer adds the integration process all the way up the lapse slope holding total enthalpy constant, then you would get similar to Verkley paper result, slightly cooler end of curve at top (~tropopause).
Say you increase atm. emissivity in the spreadsheet to .91 from .90, then find stabilized surface temperature 288.89K. If you integrate this up the slope to tropopause (I know you can’t but others can), find a slightly lower temperature there given constant enthalpy as Verkley does (i.e. some say a more opaque to IR atm. lower down near surface where atm. is denser).
Stephen continues: “That can involve changes in the near surface temperature but they would still be miniscule from CO2 alone.”
YES, if you want to call 288.89-288.23 = 0.66K near surface T increase and 0.66K decrease at great height from a 0.01 atm. emissivity increase miniscule, then the panic is over as in top post. Way to go Stephen, you got it, don’t panic. Others at least worry about it.
And isn’t that 0.66K about the T anomaly they talk about over recent climate instrumental period history? YES, hey, it all adds up. Could be Dr. Spencer’s spreadsheet is pretty good (& really it is!).
This is simple, not easy.
******
PS: Stephen presses on regardless: “You still haven’t acknowledged or contradicted the fact that: “Independent energy expended on the external surroundings during expansion (rising) is offset by independent energy absorbed from the external surroundings during contraction (falling).” which seems to dispose of your use of the d term.”
Independent energy? Expended? d term? Absorbed has physical meaning but is lost in there. Ack, I have nothing to add. This is only semi-parsable. Rewording with physics terms and math operators might help me. Already too long a post; break out the popcorn.
Not wanting to sidetrack, but Trick maybe you can answer a question.
I’ve asked for the origin of the 255K if there is no atmosphere, silence.
Tim C. – I have a couple thoughts to share. Related to the size of the panic being over in top post.
I observe those that discuss the no atm. at all earth system scenario have a much tougher challenge. This tougher challenge can be avoided simply by theoretically leaving the atm. pressure, n and V in place and discussing small mod.s theoretically to net insolation, L&O & atm. emissivity radiative transfer perturbations of the existing balance.
I observe not too many talk about small mod.s to convective and conductive heat transfers though some wonder about them.
In perturbation theory one learns that there is a “step away” size past which the system is no longer the same system. Small enough steps allow learning something about the system being studied, large enough “step aways” and the learning is reduced to 0 eventually.
Step size is related to amount of system stability. B-17s are very inherently stable – better runs over the target; F-18s are inherently unstable and have to be returned to stable control by computer. As a result, F-18s turn quicker to avoid Mach 3 missiles. Is L&O, sun and atm. more like a B-17 or F-18?
No atmosphere means no hydrostatic equilibrium assumption for the atm. & oceans. I observe that’s too big a “step away” from my learning of perturbation theory. Maybe it is not too big a step for land surface but geez, all the life forms disappear, you know the carbon based ones anyway.
Too, many discuss “feedback” loops without apparently having learned about control system theory in which open loops behave much different than closed loops.
Here’s a feedback system loop you can test on your own internal control system. Get a nice filled to the brim cup of coffee dangerously near the tipping point. Now walk up stairs not looking at the cup. Observe the amount coffee spilled.
Repeat that experiment whilst looking at the cup. Observe the amount coffee spilled.
I have done this with many different people. Some actually spill less in the open loop mode because they don’t over control the dang system into instability. It is a fun test on the way to control system class. You should feel the system stability change as you change your gaze.
In modern times, repeat that experiment while texting and speaking into your bluetooth setup. Wow.
“Independent energy? Expended? d term? ”
Just using your words.
You said:
” also independant energy expended on the external surroundings in the expansion of the parcel.”
You said:
“The intercept of the slope at surface is the near surface temperature calculated by heat eqn. balance of net insolation, L&O surface emissivity and atm. emissivity.”
My point is that if anything seeks to change atmospheric emissivity (such as more GHGs) then the circulation changes to alter emissivity back again.
That proposition remains consistent with basic physics.
The configuration of the circulation is capable of affecting emissivity by adjusting the rate at which energy flows through the atmosphere. That also involves changes in cloudiness and albedo.
Stephen4:21pm – I was afraid of that, didn’t go back and check. I will do that and improve. Still I didn’t use d as a term, I used it as a math operator which I didn’t foresee you would think was density term.
However, the earth system internal circulation changing with added infrared active gas cannot adjust near surface global Tavg. into remaining the same. Dr, Spencer’s spreadsheet is proof enough until you better his work by putting up an even better proof showing the calculations of circulation changing to return the 0.66K to 0K with basic physics we can check. Likewise, Konrad needs do the same showing the 0.66K going so high as to result in boiling off the atm.
Here we see two Aristotle type extremes, one says 0K the other boil off K and neither show the calculations.
Simpler, Stephen has not yet even put up calculations showing us how mass, insolation and gravity can possibly set global Tavg. on a planet with the global avg.d atm. opacity & emissivity being that of earth like Dr. Spencer has done. So HIS work stands as the happy medium Aristotle logic used to find an answer in his logic service to practice between the extremes.
That 0.66K is the text book simple, basic 1st course case for increased atm. emissivity affect on near surface global temperature. These basic calc.s are generally accepted as useful in practice of atm. science. They are still practicing, no perfection yet. Bettering these basics will be a tough task as they compute what we observe remarkably well.
Before the AGW theory it was my understanding that the well established basic physics was that mass, gravity and insolation were all that was needed to calculate surface temperature.
The Ideal Gas Law supports that since it contains no term for radiative characteristics.
It would certainly be beyond my capability to re-prove the past established science from first principles.
Looking at papers dealing with exoplanets it certainly seems that those three parameters are sufficient.
I can’t speak for the text books that seem to have thrown out that old knowledge in favour of a radiative alternative and I don’t put faith in anyone who seeks to rely on those text books.
Stephen 6:13pm – Got an exoplanet paper that just uses mass, insolation and gravity (MIG) I can ref.? Maybe the panic for an exoplanet is NOT over, LOL.
If past established science could have computed near surface planet global Tavg. from MIG then I would reasonably expect to see one of the 500+ posts responding to Dr. Spencer’s spreadsheet using that approach. No poster has improved on his top post to date AFAIK. Dr. Spencer’s approach existed in the texts I’ve been able to find even back to the 60’s when the Soviets reasonably correctly predicted Venus surface temperatures before building their Venera probes and before knowing the CO2 ppm.
I can’t find MIG theory and I have searched reasonably thoroughly. Logic says if that theory really did exist, and it was venerable, it would be in use today. It is not, MIG theory can’t even be reasonably found.
In Dr. Bohren’s 1998 atm. thermo text book, he disdains using math with derivatives but is forced to do so in a way he limits to bare min.s since no way around it. In that text you have a chance of reading a narrative about parcel mechanics that is better than my poor attempt. I recommend it. He’s dealt with 35years of students that he says first he had to strip of narrative from their intuitions.
You will learn why your narrative view clipped here has to be stripped off just in the parcel and gas enthalpy discussions: “Either or both of atmospheric volume or the lapse rate slope must change in order to keep surface temperature stable .” Dr. Bohren clearly shows why this is wrong. You don’t need an internet blog to find the answers.
I tried to improve what I wrote; I found it is just better to get the book. Yes, radiation is hard, he wrote another whole book on it. The amount of radiation discussion in the 1998 text is close to nil, don’t worry about having to put faith in radiation. I’ve said before, I can guarantee you will not put that book down until finished. I didn’t.
A retired Dr. Bohren wrote a nice piece right here that shows he is off put by the panic controversy as of 7 years ago anyway. I esp. like his discussion of past panics that never materialized:
“The issue of global warming is extremely complicated, and it transcends science. Views on global warming are as much determined by political and religious biases as by science. No one comes to the table about this issue without biases. So I’ll state some of mine…. People who write alarmist books are either trying to make a buck or they have an axe to grind.”
http://usatoday30.usatoday.com/tech/columnist/aprilholladay/2006-08-07-global-warming-truth_x.htm
“Got an exoplanet paper that just uses mass, insolation and gravity (MIG)”
Isn’t that the point Rog is making with the post at the top of this thread?
“First, for a given atmospheric composition, the infrared optical depth of the atmosphere will increase with pressure. As a result, a rise of [pressure] will always lead to a rise of the [radiative] greenhouse effect and temperature. Second, the horizontal heat transport increases with pressure”
The fact that authors then went off at a tangent and failed to appreciate the implications of their own data is a side issue.
Pressure is a result of mass restrained by gravity. The authors concede that that in itself affects optical depth. No mention of dependence on radiative characteristics, just mass.
Furthermore, simultaneously, that pressure affects the speed of horizontal heat transport which obviously also affects heat transport through the system to space.
So, if optical depth is affected by pressure, which is directly related to mass (not radiative characteristics) AND the speed of energy transport is also affected by pressure then there one sees support for my hypothesis.
Mass (acting via pressure) both sets the surface temperature AND provides the speed of the heat transport mechanism that ensures stability whatever happens to radiative characteristics.
Stephen 8:29pm: See slide 2 in the top post last link – the red and blue arrows are same energy balance model Dr. Spencer basically uses. The orange band is part of the temporal and spatial avg.g done for you on earth in TFK09 that Dr. Spencer uses.
“No mention of dependence on radiative characteristics…”
The basic reference for the energy balance model (EBM) used in the paper: authors discusses CO2 as important greenhouse gas.
“The authors concede that that in itself affects optical depth.”
Search on “optical depth”. Yes, but only as is well known, the top post “new paper” link says in context for a given atm. composition: “…for a given atmospheric composition, the infrared optical depth of the atmosphere will increase with pressure.”
Paper continues a low pressure regime such as well known in earth’s stratosphere means “…an increase of pressure and diffusion may cool the planet.”
Also says “..infrared optical depth of the atmosphere…which governs the intensity of the greenhouse effect.”
And more radiation dialogue, after discussing albedo, OLR, and the ERBE data used by TFK09…
“…the optical depth is milder because (1) the absorptions of different species may overlap in wavelength, (2) lines are partly saturated, and (3) the amount of water vapor, which is an important contributor is independent of p.”
Conclusion: Paper(s) are not about mass, insolation, gravity (MIG) driving mean temperature, just more TFK09 stuff along with same basic energy balance model as used by Dr. Spencer.
Stephen continues: “Mass (acting via pressure) both sets the surface temperature..”
No. Search on mass. Mass (acting via pressure) does not induce the stable surface temperature & this is not found in context in either paper. Mass induces a time lag to get to stable temperatures as shown by Dr. Spencer in the early part of the graph in his spreadsheet.
There is nothing in the papers I can find supporting MIG or a panic scenario, so the panic must be over as the top post reports.
Agreed as to panic being over.
Since you mention opacity this is how it works:
A completely transparent atmosphere effects ALL radiation from the surface. In reality that would involve no atmosphere at all.
A completely opaque atmosphere effects ALL radiation from ToA. In reality that would involve ToA being a solid surface.
An atmosphere in between radiates from somewhere in between and obviously the height at which it radiates will depend on opacity.
What you miss is that none of that matters for surface temperature.
The level of opacity simply alters the effective radiating height – correct.
But that is countered by a negative system response.
The more energy is radiated out by a higher effective radiating level the less energy needs to be radiated from the surface and the circulation slows down to deliver less energy back to the surface.
The less energy is radiated out by a lower effective radiating level the more energy needs to be radiated from the surface and the circulation speeds up to deliver more energy back to the surface.
The only equation needed is the fact that ToA energy in must equal OLR over time. The rest follows logically from that.
What one cannot suggest is that a higher effective radiating level reduces energy out which seems to be what AGW theory requires.
On that basis one would need a completely opaque atmosphere to emit ALL radiation from the surface below which is clearly a nonsense.
As would be a completely transparent atmosphere emitting ALL radiation from ToA.
“Mass induces a time lag to get to stable temperatures ”
Well of course it does. That is my point.
The longer the delay the more stored energy and the higher the stable temperature.
Mass. mass, mass.
GHGs and/or opacity seek to reduce the delay by providing an additional radiative window to space so that not all the energy needs to be returned to the surface before radiating it out.
The system then offsets that by slowing down the non radiative mechanisms.
Both you and Roy therefore admit that mass causes the delay and not GHGs.
Sheesh.
Stephen 11:22pm – I LOL’d. Cheap entertainment.
Stephen’s 8:29pm point was mass sets surface temperature. At 11:22pm Stephen’s point is of course mass induces a time lag. Yes Dr. Spencer agrees about the time lag as his spreadsheet shows. But mass completely cancels out of the stable temperature after the lag, change mass see the time lag change & see no change in stable surface temperature. Get your narrative under control man.
I shouldn’t have to tell Stephen this, Dr. Spencer’s spreadsheet will show Stephen. Geez.
Tragedy is when I stub my toe; comedy is when Stephen trips over atm. physics again and falls down a well when the spreadsheet is so easy to play with. Apologies to Mel Brooks.
Stephen 11:17pm: “A completely opaque atmosphere effects ALL radiation from ToA. In reality that would involve ToA being a solid surface….What you miss is that none of that matters for surface temperature.”….Stephen shouts up from the bottom of the well. Apparently it was dry.
Oookkayyy. Bzzt. No. Set the 0.1 atm. transmittance to 0.0. Completely opaque atm. Boom, stable surface temperature affected, moves up to 294.70K after a time lag caused by mass of the surface layer.
Geez, shall I send the rope down for you Stephen or a phablet with Dr. Spencer spreadsheet showing?
Stephen 11:17pm: “The only equation needed is the fact that ToA energy in must equal OLR over time.”
But it doesn’t. Where do you get that from? It is wrong. I have already told you it is wrong. Albedo counts. At least add it to your narrative for MIGA. I get such a laugh out of Stephen’s points sometimes. I think others must be ROFLMAO too. This is not meant in any sort of discourteous way, just a fact of life hanging out on the blogs.
Trick appears to be misinterpreting my comments as a deliberate strategy.
If the Spencer spreadsheet implies that changes in mass do not affect surface temperature then I have a problem believing it.
If the atmosphere becomes completely opaque then it acts like a solid surface without an atmosphere and radiates all incoming energy out from that point.
Complete opacity interposes a new ‘surface’ at that higher level but at exactly the same temperature as it would be for any solid surface with the same albedo without an atmosphere.
It is well established that energy out = energy in over time and that opacity/albedo also changes over time. It is the circulation that changes to alter albedo as necessary.
Stephen 4;20pm: You having a problem believing Dr. Spencer’s spreadsheet is correct is obviously no issue at all because you don’t have the modern simple, basic atm. thermo science understood yet. And it is very easy to get correct if you would apply yourself to that end. This blog is a rough means, the Bohren texts a perfect means to that end.
Because you don’t understand anything at all about radiation, ignoring its effects causes most of your misapprehension of the spreadsheet for which I observe no poster has yet offered improvement.
Here you say the atm. becomes opaque but don’t understand that it involves certain IR freq.s commonly referred to as LW and SW. The input at TOA is not net of albedo, you need to change your narrative to MIGA, it takes albedo to get in balance. I will let Stephen ponder on that because I don’t expect any improvement from Stephen anymore.
If you contend that a radiatively inert atmosphere with significant mass has no greenhouse effect then there is no hope for you.
Stephen 6:11pm: Not sure what you mean by”inert”. If you mean atm. emissivity set = 0 for earth, then Dr. Spencer’s spreadsheet shows the satellites will measure global avg.d 256.12K and thermometers suspended in the atm. as today would measure global avg.d 256.12K from the remaining convective and conductive heat transfers after the lag to equilibrium.
Here’s a good challenge that will further your modern atm. science understandings. Explain Dr. Spencer’s spreadsheet to me. If you don’t get something in there, find a ref. at your library, or on line. Study up on it. Then complete the explanation. If you ask me to do so, I’ve already explained it somewhere and it didn’t take.
Roy’s spreadsheet omits the downward portion of the adiabatic energy exchange between surface and atmosphere.
Instead he replaces the missing downward half of the exchange with DWIR
That makes the numbers balance but it misleads as to causation.
If one relies on DWIR then of course GHGs and aerosols appear to cause all of the greenhouse effect.
If one uses the correct adiabatic processes then the entire mass of the atmosphere is responsible.
That is the nub of that particular issue.
There is an entirely separate issue as to whether GHGs have any net thermal effect in the light of the available negative system responses.
Stephen 9:20pm: “Roy’s spreadsheet omits the downward portion of the adiabatic energy exchange between surface and atmosphere.”
Dr. Spencer’s spreadsheet a) does not omit the downward portion of adiabatic energy exchange in between surface and atmosphere and b) the correct amopunt DWIR is in there too and not as a replacement. Spreadsheet can be used to show Dr. Spencer agrees the panic is over. Explain to me how that can be.
If either of these a) and b) were not handled correctly to modern atm. thermodynamic & heat transfer physics, the spreadsheet would calculate the wrong answer for equilibrium near surface thermometer global Tavg. = 288K and/or the satellite global avg.d 255K.
The spreadsheet explains both to within ~1K remarkably well; spreadsheet even explains the time lags due to mass. Quite an elegantly simple, basic spreadsheet I’d say. It is fully correct and traceable to 1st principles.
Stephen will have to try harder to explain why that can happen. He is not quite there yet. A very good challenge & he is starting down the road of improved understanding. Dig in to the calc.s Stephen, you will be rewarded with improved appreciation of nature.
I will be rewarded with an explanation that sticks, maybe.
“The spreadsheet explains both to within ~1K remarkably well; …”
Of course it does Trick… it was fitted, to match the math of the model at the intersection of the correct answer, just like N&Z was fitted that Dr. Roy Spencer spent a lot of time trying to put them in their place. Just try to take Roy’s model and change the sea surface boundary layer thickness from 5 meters to 2, or worse one. It is an unstable model as it stands and is not real… DWLR does not warm the ocean top layer.
Have you not looked at what his equation is saying? There is only one equation driving that spreadsheet. Take for example the second month. He takes the month’s before temperature and adds an amount of temperature he assumes the DWLR warms the top layer of the oceans. He starts this calculation by taking the 161 surface solar absorption (B5) and sutracting (removes from consideration) that which is convected upward along with the latern heat (B7) leaving the net upward IR from the surface of 64 W/m² (TFK says 63 W/m² here). That 64 W/m² is primarily window radiation and watch, he is going to use this as part of what warms the top 5 m of the oceans.
He then also sutracts the temperature brightness of the preceeding month’s surface temperature at ε=1 of (σ·230^4)= 158.7 W/m² leaving so far -94.7 W/m². Next he adds “back radiation” from a constant 283 K (B8, what’s this??) for the atmosphere and basically reflecting (1 – 0.1 (B9)) or 90% of this atmospheric IR energy downward and uses this reflected heat originating from the surface + window via the heat capacity of the top 5 meters of the ocean (B3) to get his temperature offset added to the temperature of the month before.
And you buy and accolade Roy for this model protraying as what happens on this planet, temperature never 6 months from a close equilibrium?
wayne 11:32pm – The time lag stuff is jury rigged as you write, just to show that aspect of how the mass affects shape of curve. I would sort have appreciated that analysis from Stephen. The equilibrium stuff is what I am really interested to discuss not the lag. Spot any issue there? (If so, Stephen, no peeking, do your own work, you will benefit more, LOL.)
I’m happy to receive help from wayne on the maths. Have previously told him that privately.
Trick writes as though he knows of an answer that I should be putting forward.
Do tell.
I suspect that I have covered the relevant issue in prose but cannot translate to maths in terms that satisfy Trick.
Likewise, Trick cannot translate to prose in terms that are meaningful to me.
Maybe a little to help you Stephen along the path of the explicit maths. Stephen, some of what you say in your long streams of ‘on the top of your head’ ideas are somewhat correct, or close and related, but some are clearly so not correct and maybe if you study in the simple math of what does govern your adiabatic and diabatic ‘loops’ you will see where you are out of bounds when you break known correct physics and thermodynamics. I’m still learning but I seemed to pass you by on this about a year ago and wish you would take the next step to stop until you know every which way you can view the Poisson’s equation first.
No one doubts that insolation affects climate in relation to atmosphere profiles. It seems we are still speaking of surface temperatures, no? No one doubts that mass and pressure are directly related, or I don’t think so. Mass equals pressure / gravitational acceleration, so saying equal mass levels in an atmosphere is identical to saying equal pressure levels (like 500 mb level), they are the same thing. I sometimes say mass, and N&Z say pressure, but we are speaking of identical properties, in physics that is ok, you just have to know just enough to translate on the fly. But here’s a bit of math on gravity buried deep within that seems few ever consider and I cringe sometimes what is said on it. In one respect gravity does not matter at all, not sperically, but in one other aspect it is integral in the terms of the Poisson’s equation and you need to know why. So follow this.
Ru – universal gas constant = 8.3144 J/kg/K
Rs – specific gas constant for a given gas mixture
cp – heat capacity viewed at a constant pressure
cv – heat capacity viewed at a constant volume
gE = Earth’s grav. accel. = 9.80665 m/s²
gV = Venus’s grav. accel. = 8.87 m/s²
mwAtmE = Earth’s Atm gases molWt = 0.0289644 kg/mol
mwAtmV = Venus’s Atm gases molWt = 0.04345 kg/mol
lapseE = Earth’s trop. lapse = 0.0065 K/m
lapseV = Earth’s trop. lapse = ~0.0080 K/m
Ts, Ps, Ds – surface temperature, pressure and density
T, P, D – temperature, pressure and density at a given vertical point
Below I will sometimes hold too many digits of accuracy so round down as needed but this is so the calcs can be checked without question that they are close, so the extra digits. I have read that in Venus’s case the temperatures are only known within ±2.5K so allow some leeway.
T = Ts * (P/Ps)^(x), one form of the Poisson’s equation (potential temperature variants) to calculate a potential temperature. As long as a parcel of air is located vertically at the natural potential temperature level no convection lift or sink will, or should, occur here, if not the change to correct this imbalance is instantaneous, the atmosphere is stratified in this manner. Most of the atmosphere is not convecting but within the lower 1.5 to 2 km mixing boundary layer on the average. I call it the lapse rate curve’s surface tail, it wiggles wildly daily. As used in the programs to calculate the ’76 and ISO standard atmospheres this exponent ‘x’ term takes the value related to the hydrostatic constant (later).
You often see potential temperature stated as T = Ts * (P/Ps)^(0.286) in texts when speaking of adiabatic. ‘x’ is usually defined as this 0.286 when the potential temperature is calculated for perfectly dry Earth air which never really occurs. This exponent term can be viewed from more than one side and this should be heeded to really understand what this simple equation is ‘saying’ to us in it’s various forms. One way is to say this term is Rs/cp. Another equally valid way is to view this as (Ru/mwAir)/(g/lapse). See defs above. If you are looking downward instead of upwards or calculating pressure from the temperate ratio this exponent becomes 1/x so keep in mind the value and it’s inverse are really speaking of the same relation but inversed. Later you will see I use 5.25577 and 0.190267 regularly when probing our averaged atmosphere, they are just the inverse of each other.
Look first at (Ru/mwAir). For Earth that would calculate to be 8.3144 J/kg/K / 0.0289644 kg/mol = 287.056 J/mol/K or is the Rs specific gas constant for Earth’s atmosphere gases, in the troposphere at least. Now look up the cp of dry air… it is usually given as 1004 J/mol/K so take the 287.056 J/mol/K / 1004 J/mol/mol to get the unit-less 0.286 exponent used to govern dry adiabatic movements (never real).
Next consider the (g/lapse) term. For Earth that is 9.80665 m/s² / 0.0065 K/m = 1508.7 (m/s)²/K. On the the units. that is equivalent to what is known as the constant pressure heat capacity but hard to see at first. Since this is pure SI units the unit mass of one kg and the unit mol are implied to give units progressing as (m/s)²/K –> kg·(m/s)²/mol/K –> kg·v²/mol/K –> Energy/mol/K –> J/mol/K.
Combining these two terms as a ratio, under (Ru/mwAir) / (g/lapse), gives 287.056 / 1508.73 = 0.1902633 for the average real-atmosphere Poisson exponent as used in calculating the standard average atmosphere as the ’76 version or the ISO version. It’s inverse, 1/x, is close to 5.25577 and is unit-less also related to the heat capacity ratios. If you take the time to look at how, for the air force I believe, this was performed on the web you will NOT find this figure, the 0.1902632 but you WILL find it’s form missing that lapse divisor, 0.0065 / 0.1902633 = 0.0341632 which is what is termed as the 34.1632 K/km (now use meters) hydrostatic constant. As you can see we are speaking of the same values throughout but in a different form excluding the lapse for later inclusion.
What this is screaming at you that most of the bulk on atmospheres, the thicker tropospheres, are all tightly governed by this equation with proper values applied, and they may vary though slowly at different altitudes, usually due to permanent cloud levels or non-smooth concentrations of the molecular composition.
My whole point of going to this much detail is to now turn our view to another planet with a thick atmosphere and see if it works exactly as our atmosphere works, Venus.
Calculate the same as above for Venus. The (Ru/mwAir) / (g/lapse) becomes (8.3144 / 0.04345) / (8.87 / 0.007977) to give an Poisson exponent of 0.17209.
What is the ratio of this Poisson exponent between the two atmosphere’s that create the correct profile as close as we now know them?
0.1902633 / 0.17209 = 1.1056
What is the ratio of the two planets gravitational acceleration?
9.80665 / 8.87 = 1.1056
This raises the question is the lapse of Venus’s atmosphere of 0.007977 correct (I fudged that down a tad from the general 0.008 K/m that so many state)? Maybe, maybe not, but checking various graphs on the web this value is so very close. Does this imply that the atmospheres are in fact exactly equivalent in profile through the other two parameters of molecular weight and their lapse rates irregardless of their composition but for the difference in gravitational pull? Don’t know yet, next chapter is to check on Titan and Jupiter’s atmospheres. But here’s a twist, remember that when dealing with spherical layers inward that height does not matter in contrast to a plane-parallel view, one self-absorbs what radiation nearly horizontally misses the inner layer and plane-parallel does not, and that self-absorbing exactly cancels anything having to do with “height” or “altitude”.
But just like my last top-post article says you can also look at Venus’s atmosphere as stacked Earth atmosphere properties, totally opaque (within optical thickness limits) in h2o, co2, and other ghgs if and only if you first remove from Earth’s atmosphere all radiation that escapes without further interaction with molecules of any kind, even a small portion of N2, O2, and Ar. They collide and have electrons too. Here using the Earth as a lab knowing the numbers well to probe Venus’s atmosphere with our atmosphere. That particular view as shells in shells or spherical layers within spherical layers (cannot be plane-parallel) and that same thing produces the same profile of Venus’s atmosphere but it is off by a few K right in the middle of the troposphere. Amazing to me. There is some base physics principles in play here that it seems no one is yet addressing but you really need to keep both views in focus because they both are really two sides of the same coin. One is radiation and the other is Poisson in the thermodynamics side.
Then there is another form of this relation by rearranging the equation that
log(T/Ts) – log(P/Ps)^x = 0
same as
log(T/Ts) = log(P/Ps)^x
same as
x = log(T/Ts) / log(P/Ps)
same as that inverse form,
1/x = log(P/Ps) / log(T/Ts)
same as
T = Ts * e^( x log(P/P0) )
This time there is the ‘e’ exponent operator, there is the reason this entire sequence is a common and simple exponential a = b*e^c.
Notice the same general form, x being a simple ratio of two terms once again but this time revealing what this really is, the ratio of the logs respectively of the temperature ratio to the pressure ratio, that’s all.
This is not even speaking of the (γ-1)/(γ) form of the ‘x’. Gamma (γ) being the cp/cv heat capacity ratio. Almost like, or really is like, that (Ru/mwAir)/(g/lapse) = (γ-1)/(γ) = (cp/cv – 1)/(cp/cv) = (Rs/cp) and these ratios are all the same value and can be extended all of the way back to the effective molecular degrees of freedoms being expressed in the real atmosphere and this governs any convection. That relation holds so much detailed information on each atmosphere and the profile and has nothing to do with radiation you see (but using equivalence it does, like the stacked radiating layers forming the same profile, but in a way, it can’t, by the opposite limiting physics principle of ‘effective potential temperature’ that even takes the latent heat into account generally said to be decoupled from radiation effects. It is like trying to get a mental view of a five dimension surface, the math is simple, the concept escapes you from really understanding it. Start simple by contemplating why the cp term is 1508.7 instead of 1004 basically saying without thinking that lapse is 0.0065 and not 0.0098 but this time not trivially accepting it at face value. Read up on this, if it takes you months to really understand every aspect of this one topic you are faster than I, but if you can make the jump to the math here, it’s not too complicated math (but the concepts are) it would sure help support and give credence to your thoughts and words.
Some will ignorantly say, well, this just uses the lapse rate, nothing to see here. But they overlook that (γ-1)/(γ) is the same number and this has nothing to do with “lapse rate”, or radiation. Think again. I’ve purposely stayed out of the qm & statistic mechanics, partition functions, what shows you how this and all forms reach back to first principles but I’d stay more on the higher levels as I’ve described here. No need to delve into that area of the core derivations.
I can’t help but to see that this leads somewhere that you never read or hear about, but I’ve not reached the very end of this topic myself, yet, none of all of the papers, meteorology texts, radiative texts, on atmospheres and physics texts, hundreds of them, have been little help shedding light into this complicated area.
Stephen 3:09am: “Do tell.”
If I do tell, as I HAVE done, Stephen will ignore as always and continue to explain incorrectly and draw unphysical & unnatural narrative conclusions as I continue to observe. The only way I can see for Stephen to improve to correct meteorological science conclusions is to do the “Do tell” thing on his own and explain to me that Dr. Spencer’s equilibrium in his spreadsheet works so remarkably well.
Right now, Stephen can’t do so, even explain the most basic modern meteorology. Stephen will need to “do” some self help to catch up to Dr. Spencer and enable an explanation why his spreadsheet equilibrium calculations work so close to both earth surface thermometer measurements at 288K and satellite measurements at 255K.
******
NB: For example as in above thread: Stephen – the lapse rate conclusions you draw based on parcel PE+KE are incorrect because your narrative ignores the energy in the parcel p*V term.
Gas parcel total relevant energy = its enthalpy = internal energy + external energy to&from environment from parcel’s expansion&contraction.
In a basic meteorology text which Stephen claims to have studied long ago, this is given as enthalpy per unit mass = U = PE + KE + p*V where V is the specific Volume of the homogenous density parcel (specific Volume =1/density).
Stephen’s parcel PE+KE narrative draws incorrect conclusions due to ignoring the p*V energy term in changes & as a result incorrectly explains lapse rate i.e. Stephen’s narrative doesn’t conserve energy as a parcel moves up or down.
Dr. Bohren’s 1998 text will explain this in narrative and pictures for Stephen’s self help endeavor.
“Stephen’s narrative doesn’t conserve energy as a parcel moves up or down”
Of course it does.
PE is energy just as KE is energy but it doesn’t register as heat.
Exchanging KE for PE and reversing the process conserves energy perfectly.
You really are talking a load of rot and wasting everyone’s time.
wayne.
Many thanks for your hard work in producing that detail and I will dig into it but I’m not yet convinced that you are necessarily ahead of me 🙂
I still think that once you have worked through all that detail you will boil it down to a simple truth not dissimilar to mine.
Before Newton who would ever have thought that so much could be explained by a simple downward attraction towards a centre of mass ?
Or before Einstein who would have thought that E=mc2 would explain so much ?
Nothing I have done is comparable but the solution really is going to be so simple and obvious that many will be banging their heads together.
Stephen 8:52pm: “Exchanging KE for PE and reversing the process conserves energy perfectly.”
No, not for a parcel in an atm. & it is not of waste of time to learn something Stephen. The increase in a parcel’s enthalpy is equal to its added heat. Exchanging KE for PE does not conserve the parcel’s energy. The parcel’s p*V energy term is also affected moving in an atm. Stay with it, keep working & searching for the right answers and conclusions, your narrative can be made correct.
The conversion of KE to PE restores the previous enthalpy but at a different height within the gravitational field.
I thought that would be obvious.
Overall, energy is conserved.
Stephen’s current list for learning about basic nature of meteorology and deeper understanding why the panic is really over, pretty sure some library time would be helpful:
1) Explaining Dr. Spencer’s spreadsheet equilibrium working so well in nature (288K & 255K).
2) Incorporating atm. gas enthalpy correctly by adding p*V term to his narratives on parcel PE+KE.
3) Learning why it is impossible (Stephen’s 6:04 am trip down the well) for: “The conversion of KE to PE restores the previous enthalpy but at a different height within the gravitational field.”
Nature has another important e word for 3) that Stephen misses also.
I have no time at the moment to explain due to attending NCAA softball playoffs this weekend (maybe I should change my screen name to “ball4” now NCAA hockey is over) and it is way better for Stephen to puzzle that out himself. Better foundation for learning to “take”. Even a suggestion from Stephen as to the other e word would be showing some learning about basics of natural meteorology.
I think you should try to explain rather than playing games.
If you use mathematical symbols please confirm the meaning of each symbol so that we don’t repeat the misunderstanding caused when you suddenly started using the symbol ‘d’ during a conversation that considered density amongst other things yet it turned out that you used it to mean something else entirely.
Trick says:
May 17, 2013 at 2:59 pm
U = PE + KE + p*V
And that it wrong to ignore the work term p*V.
It is not ignored in this derivation of the lapse rate posted on this site.
E2 = E1 + m0 g ∆z + m0 Cv* ∆T + (P1 V1 – P2 V2) ( 1)
∆E = m0 g ∆z + m0 Cv* ∆T + (P1 V1 – P2 V2) (2)
The first term at the right hand side is gravitational potential energy difference. The second term is the increase (actually decrease since ∆T is negative) in molecular kinetic energy and the third term is the change in work done on the atmosphere by m1 and m2 at the two static locations under consideration.
It follows from P1 V1 = m0 R* T1 and P2 V2 = m0 R* T2 that
(P1 V1 – P2 V2) = m0 R* (T1-T2) where ∆T = T1-T2. Enter this into equation (2) and we get
∆E = m0 g ∆z + m0 Cv* ∆T + m0 R* ∆T (3)
R* = Cp* – Cv* gives
∆E = m0 g ∆z + m0 Cv* ∆T + m0 Cp* ∆T – m0 Cv * ∆T or
∆E = m0 g ∆z + m0 Cp* ∆T (4)
The definition of an adiabatic energy situation is given by ∆E = 0 which leads to
g ∆z + Cp* ∆T = 0 or (5)
∆T/ ∆z = -g/Cp*
The PV term is included but does not appear in the final equation. PV is proportional to T. It is hidden in the increase to cp from cv.
g/cp = 9.78 K/km, g/cv = 13.7 K/km
“the work term p*V.”
Thanks Roger.
I also considered that to be included in my narrative when I pointed out that conversion of KE to PE also involved a rise in height.
When the rise occurs the reduction in pressure results in reduced density so the molecules move apart.
That expansion does work against the intermolecular attracting force and that work converts KE to PE for a cooling effect.
I think Trick doesn’t understand the wide combination of variables involved and so gets lost in the maths.
Stephen Wilde says:
May 18, 2013 at 9:20 pm
conversion of KE to PE also involved a rise in height.
The rising parcel of air does work against gravity and the pressure of the air around it.
There are no inter-molecule forces in an ideal gas.
“There are no inter-molecule forces in an ideal gas.”
Then explain this:
http://en.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect
“As a gas expands, the average distance between molecules grows. Because of intermolecular attractive forces (see Van der Waals force), expansion causes an increase in the potential energy of the gas. If no external work is extracted in the process and no heat is transferred, the total energy of the gas remains the same because of the conservation of energy. The increase in potential energy thus implies a decrease in kinetic energy and therefore in temperature”
“The rising parcel of air does work against gravity and the pressure of the air around it.”
Yes it does, but if the rise is a result of adding more energy to the system thereby warming it there WILL be a rise in surface temperature even after the necessary conversion of KE to PE.
That extra energy in the system being provided by more mass, gravity or insolation.
Where an increase in the power of the radiative characteristics of constituent molecules is concerned there is no total energy added to the system yet those radiative characteristics nonetheless cause an expansion.
That expansion converts the bulk of the additional KE in the air to PE by working against gravity as you say but what about the residue ?
If no extra energy is added to the system from more mass, gravity or insolation then the Joule Thomson Effect removes that residue for a zero thermal response to a change in radiative characteristics.
Stephen Wilde says:
May 19, 2013 at 7:14 am
explain this
Because of intermolecular attractive forces (see Van der Waals force), expansion causes an increase in the potential energy of the gas.
The derivation of the lapse rate by Hans Jelbring ( and all others ), assumes an ideal gas. Ideal gas particles are elastic spheres.
Van der Waals forces are caused by dipoles or induced dipoles.
Here is a recent contribution to the climate debate by The American Chemical Society. An organisation I as a chemistry grad used to revere, but not now.
http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_SUPERARTICLE&node_id=845&use_sec=false&sec_url_var=region1&__uuid=157fb6f1-17ad-45dd-a5e2-4d2afd4632de
The expansion [ of rising air ] requires the gas to do work against the surrounding atmosphere, thus cooling the gas as it rises higher into the atmosphere.
I wonder why there is no mention of the work against gravity.
I think the answer might be that Hans and others correctly assume that the ideal lapse rate set by mass and gravity is only realised at a given location within an atmosphere in the situation where the atmosphere itself is comprised of an ideal gas.
Where the gas is not ideal (which is always) then the actual lapse rate varies from the ideal depending on how far the gas itself varies from ideal.
That is why one gets departures from the ideal lapse rate throughout the vertical column around all real planets.
However, for the atmosphere to be retained the atmosphere averaged out as a whole must achieve the ideal lapse rate once all variations from the ideal are netted out.
I see that role as being fulfilled by the atmospheric circulation.
The atmosphere being three dimensional any expansion must push both against gravity and the intermolecular attractive force.
I think that if extra energy is added to the system to cause expansion then the expansion is accompanied by a rise in surface temperature and system energy content.
Where expansion occurs without extra energy being added to the system (such as a mere redistribution of available energy as proposed to be effected by GHGs) then the expansion is not accompanied by a rise in surface temperature or system energy content.
In the former case the additional energy is enough to overcome the cooling effect of expansion pushing against the two opposing forces.
In the latter case there is no new energy so the effect of GHGs is cancelled out by the expansion converting just enough KE to PE to maintain ToA radiative energy balance.
Stephen 7:23am: “If no extra energy is added to the system from more mass, gravity or insolation then the Joule Thomson Effect removes that residue for a zero thermal response to a change in radiative characteristics.”
Here Stephen attempts invoking an effect he doesn’t fully understand in a way that is meaningless.
Stephen 4:32pm: “I think you should try to explain rather than playing games.”
No games just science, math and an attempt toward pointing Stephen to working on some self help.
Here’s self help for Stephen, my 1:35pm list expanded:
“Stephen’s current list for learning about basic nature of meteorology and deeper understanding why the panic is really over, pretty sure some library time would be helpful:
1) Explaining Dr. Spencer’s spreadsheet equilibrium working so well in nature (288K & 255K).
2) Incorporating atm. gas enthalpy correctly by adding p*V term to his narratives on parcel PE+KE.
3) Learning why it is impossible (Stephen’s 6:04 am trip down the well) for: “The conversion of KE to PE restores the previous enthalpy but at a different height within the gravitational field.”
I now add a 4th:
4) Stephen attempts to explain atm. processes with his adiabatic loop then invokes Joule-Thomson Effect to explain the atm.’s adiabatic loop with a link Stephen supplies at 7:14am.
Here are some pointers Stephen, for you to work on self help by getting your narrative correct to atm. physics and radiative transfer of heat while I am at softball games:
1) See page 33 of Dr. Bohren’s 2006 text
2) See relevant intro. to enthalpy section in any atm. thermo text, I recommend Dr. Bohren’s 1998 text
3) See Caballero on line notes/text, search on “enthalpy”, or see sec.s 2.15,2.16, 2.17 pp32-37.
4) Note in the link given by Stephen who applies Joule-Thomson Effect to atm. adiabatic processes: “The cooling of a gas by …. adiabatic process …is not Joule-Thomson cooling.”
Also in that link they discuss the p*V term during changes (for example a rising or descending parcel) as an infinitesimal differential change in pressure or V*dP. Stephen admits he always thought this was V*density*P at 4:32pm. This is the state of Stephen’s self help, just a start, long way to go.
As a slight aside, you can buy a thermopile for US $15 here:
http://www.sci-supply.com/closeup.asp?cid=124&pid=481&offset=0
Then anyone can build their own cheap, uncalibrated pyrgeometer/IR detector.
[mod: This is not a thermopile as used for instrumentation, is a solid state semiconductor device, why it says peltier and mentions cooling and 12 Volts. –Tim]
tjf, see here
” ideal lapse rate ”
That only occurs at zero humidity (never in the real atmosphere) not from a deviance from the ideal gas law by inter-molecular attraction or repulsion. Don’t you remember Stephen, this ‘check to see if there was a meaningful Van der Waals’ earlier a year ago, there is so little you can rule it out here. What you are seeing changing the lapse is from a change in water vapor and absorption and release of latent heat. You didn’t look into that lengthy explanation I gave you above did you? The 1004 J/mol/K found at g/cp being different than the 1508.7 J/mol/K used to compute the standard atmosphere has to do with the mean water vapor concentration. If abnormally high, this is cp > 1509, if below normal water vapor it is 1509 > cp > 0. You really don’t have to try to prove that the IGL is incorrect if used in relation to our atmosphere. Maybe near the surface of Venus at >90 atmospheres it applies, but not here.
That’s why the cloud base is so important concerning your “adiabatic and diabatic loops”, that is the vertical level where the humidity takes a marked drop and from that point upward there is little evidence of adiabatic loops, just turbulence from the horizontal winds. You lost me long ago on what exactly you are trying to prove.
If you are trying to prove that what the IPCC has been saying all along is wrong, you’re looking in the wrong direction. Really it has already been proven wrong within the Entering the SkyDragon’s lair post (you have insight and read between-the-lines of those thousand of comments) and about Eshback’s steel shell. Tim Folkert’s gave it all away as he mistakenly drew attention to the fact that radiation from any layer of any atmosphere with a temperature looking inward does not matter at what altitude this layer exists if and only if you use spherical geometry and not a plane-parallel viewpoint. Three or four years ago there was some AGWer, I think JShores or TFolkerts who showed how a parallel-plane view of atmospheres was identical to viewing it spherically. I accepted it and that was my BIG mistake. They are NOT the same and all of this talk of the height of the effective radiation level (ERL) is totally wrong, there is no “raising the ERL” that by the lapse rate makes the atmosphere lower and to the surface warmer… that cannot happen due to the GEOMETRY !! Shame on Perrihumbert or whatever his name is, shame on all of the AGWer “scientists” propping this fallacy. And it was them that gave it all away… that is the reason why the temperature is not increasing and never will without decreased albedo or a warmer sun. This is also why Venus is really no different that Earth’s atmosphere irregardless of CO2’s concentration since both are opaque except above the tropopause. (thank TJFolkert’s daily and never use the plane-parallel view of an atmosphere)
So Stephen, what are you trying to do?
Phew, lots of stuff to absorb there but is some of it just a diversion ?
I’m open to education about Van der Waals and the Joule Thomsom Effect but not entirely sure whether it matters.
wayne is perceptive in noting that I seem to be drifting off track. I’ve been doing that in order to try and provoke the supply of any information that disproves my view that radiative characteristics do not affect surface temperature or system energy content and that the reason they fail to do so is due to circulation adjustments.
Even that is only a secondary issue for me because it is enough to demolish AGW fears to simply involve total atmospheric mass in the greenhouse effect rather than the radiative characteristics of GHGs.
wayne pulls it back to the essential issue:
“Tim Folkert’s gave it all away as he mistakenly drew attention to the fact that radiation from any layer of any atmosphere with a temperature looking inward does not matter at what altitude this layer exists if and only if you use spherical geometry and not a plane-parallel viewpoint.”
The spherical geometry issue is what increases the volume available for an atmosphere to occupy as it expands outward and is therefore critical to the decline in temperature with height due to reducing pressure and more distance between molecules and between molecules and the surface.
A point I have raised over at Roy Spencer’s is that one can regard the atmosphere itself (independently of solar throughput) as having a zero radiative flux. In other words no net upward IR and no net downward IR.
One is driven to that conclusion by noting that there is radiative balance at ToA between atmosphere and space and also radiative balance at the bottom of the atmosphere between surface and atmosphere.
So, just using any numbers as an example if 240 comes in at ToA then 240 goes out at ToA and if 150 leaves from surface to atmosphere and 150 leaves from atmosphere to surface there is no net flux within an atmosphere other than the basic throughput of solar energy.
If the only net flux that can exist within an atmosphere is from solar energy passing through then GHGs cannot create a different net flux without a compensating circulation adjustment that cancels out their effect.
Now I’m sure that is the reality but demonstrating it is quite a problem.
Of course no diversion meant Stephen. This is not my kind of day. Two tornadoes six miles north, another ten south. Kept me glued to the NWS radio and tv all afternoon. Will get back to you tomorrow but it may just be a replay of today. Well, that’s normal Oklahoma, the cooler the upper air the worse our weather and this was one cold and thankfully wet spring.
wayne,
With regard to the possible ‘diversion’ I was referring to Trick’s post rather than yours.
Have fun with your local weather 🙂
“Equations convey a lot of information in a very few symbols, which is why they’re so popular, but they’re also a crutch; a device used to support a weak understanding and make it seem strong. Equations can be used by a student with no understanding to fake competency.”
from here:
http://physics.info/gas-laws/
In the end, it all just boils down to whether the radiative properties of gases can change the volume of those gases without the thermal effect of the radiative properties being negated by the expansion.
GHGs are supposed to absorb more energy so if they do then they must rise and move apart from the surrounding molecules which gives a cooling effect as work is done against gravity and the intermolecular attractive force.
I see no evidence that an expanding gas fails to cool sufficiently to offset the effect of radiative characteristics.
It is a different matter if more energy is being supplied from outside the system but that is not the case with GHGs.
“More CO2 = higher temperatures when everything else was held constant. ”
This is a risible example of circular reasoning and definition. OF COURSE if no other influences are allowed, the selected option drives all changes. An extreme example of “hidden variable fraud”, IMO.