Let’s play Stump the Scientist

Posted: February 3, 2013 by Rog Tallbloke in Analysis, atmosphere, general circulation, Gravity, Measurement, methodology

Posted on Dr Tamsin Edwards site 17 hours ago and approved by her. No reply yet:

tallbloke says:

Stump-tailed-MacaqueHi Tamsin, you said:
“At the heart of them [Climate models] are basic laws of physics, like Newton’s laws of motion and the laws of thermodynamics”.

I have spoken to many climate scientists who seem to think that at equilibrium, the troposphere would be isothermal, in accordance with the Maxwell-Boltzman distribution. They argue that there would be no lapse rate without radiation and convection. Do the models make this assumption too?

If they do, it seems like a grave error to me. The true situation isn’t like Maxwells ‘isolated column of gas’ for several reasons. Although it is bounded by Earth and space, its volume is not constrained. NASA has confirmed observationally that since the Sun went quiet in 2004, the thermosphere has shrunk by 30% and the average altitude of the cloud deck has dropped by 30m.

Gravity acting on the mass of the atmosphere produces a pressure gradient by pulling the gas against the solid Earth. Because air is compressible, that pressure gradient acts to produce a density gradient. Because the molecules nearer the surface are pushed closer together, there are more of them in a given volume. That makes it more likely that water vapour and co2 molecules in the volume will intercept and absorb photons of incoming solar energy and photons of outgoing long wave radiation.

Because the path length is short, these energised molecules soon share their extra energy with surrounding molecules of nitrogen and oxygen which make up the bulk of the atmosphere. The ensemble has a heat capacity. Therefore, the denser near surface air will get hotter than the less dense air at altitude.

Naturally, in accordance with the gas laws, the warmer air nearer the surface will have been expanded by the higher temperature and its density thus lowered again, but this won’t fully offset the effect due to gravity acting on mass to raise pressure and density to form a gradient. (We should calculate the value).

So even before we consider convection and radiation, there will be a ‘pre-existing’ lapse rate due to these simple thermodynamic-gravitational considerations.

Is it included in the models?

Comments
  1. tjfolkerts says:

    “I have spoken to many climate scientists who seem to think that at equilibrium, the troposphere would be isothermal, in accordance with the Maxwell-Boltzman distribution.”
    Your sentence tries to set up self-contradictory conditions.

    “The true situation isn’t like Maxwells ‘isolated column of gas’ for several reasons.”
    You provide the solution to your own misunderstanding. An equilibrium column WOULD be isothermal according to the laws of thermodynamics — so that is a perfectly reasonable thing to think. But the troposphere is NOT at equilibrium — it “isn’t like Maxwells ‘isolated column of gas’ “. It is constantly being heated at the bottom and cooled at the top, so it is definitely not “isolated”. So it is perfectly reasonable to think that troposphere will not be isothermal.

    I doubt any scientist or model assumes an isothermal, equilibrium condition in an atmosphere that is clearly neither isothermal nor equilibrium.

    “That makes it more likely that water vapour and co2 molecules in the volume will intercept and absorb photons …
    So even before we consider convection and radiation … “

    But you already DID consider radiation — right in that other sentence! It is exactly that consideration — that the atmosphere loses energy by radiation from the top, and gets energy by radiation at the bottom (and by conduction & latent heat) — that leads to the lapse rate. Yes, gravity and density and pressure play a role, but ultimately you need the energy flow (which is present naturally in every atmosphere of every planet) to create the lapse rate.

  2. Konrad says:

    Lapse rate is confusing to many, and understandably so. In meteorology it is dealt with equations that provide working assumptions. To truly understand lapse rate you cannot rely on the equations and “working assumptions”, you need to be the equal of Kelly Johnston, you need to “see the air”. I am not in Kelly’s class. I will attempt to describe as best I can.

    There is lapse rate stagnation then reversal above the tropopause. Most radiative gases in our atmosphere exist below the tropopause. This should give readers the initial knowledge that radiative gases have an important role in establishing the reverse lapse rate in the troposphere.

    If the gases in our atmosphere did not move, IR radiation to space would still establish a minor lapse rate in the lower atmosphere heated from the surface. The lapse rate we observe is however far greater. This is because of continuous vertical convective below the troposphere. Gases cool on assent and heat on decent. Over a long period of time, horizontal conduction establishes the lapse rate we see below the tropopause.

    Dr. Tamsin, no existing atmospheric maths will help you here. You need to develop new models. You need to develop them on the basis of empirical experiment. It’s hard, but no one ever advanced science by agreeing with the “consensus”. You will be putting your career in jeopardy, but what is more important, your career or science?

  3. omnologos says:

    Every planetary atmosphere we know of has a troposphere and a lapse rate. This doesn’t depend on CO2 and water vapour being available.

  4. Q. Daniels says:

    Roughly 25 milliwatts per square meter upwards transport will turn an isothermal column to adiabatic.

  5. oldbrew says:

    It has also been argued that the lapse rate is directly related to a planet’s distance from the sun, and that there is a lapse rate formula: La = g/Cp

    http://wiki.answers.com/Q/What_is_the_dry_adiabatic_lapse_rate_on_Venus
    http://theendofthemystery.blogspot.co.uk/2010/11/venus-no-greenhouse-effect.html

  6. tallbloke says:

    Q. Daniels: Interesting metric, can you show us how that is calculated?

    Tim F: Fair points, I wrote the comment in haste. But I think the underlying question is still a valid and important one,given the way the radiative theory as it is presented in textbooks skates over the gravitational-thermodynamics of planetary atmospheres.

  7. Bryan says:

    The centre of mass of an atmospheric column rises and falls on a diurnal basis.
    This is a pumping action that smooths atmospheric temperatures.
    This action is not related to the IR active gases( apart from the cooling at the TOA).

  8. Hans Jelbring says:

    Tallbloke: “But I think the underlying question is still a valid and important one,given the way the radiative theory as it is presented in textbooks skates over the gravitational-thermodynamics of planetary atmospheres.”

    James. R. Holton didn´t do so, at least not when he was young. You could claim that Holton made his derivations ignoring the impact of radiative processes, which is a better approach than ignoring the impact of 2nd law of thermodynamics (based on energy). He was appointed as a doctor of honor at Stockholm University and I used his book “An Introduction to Dynamic meteorology” when studying meteorology. Later I have been amazed that his derivation of the dry and “quasi wet” adiabatic temperature lapse rate is so little known at Anglo universities. It is true that other professors like the head of Meteorology Bert Bolin seems to have been unaware of that fact and the devastating impact Holton´s knowledge would have had on Bolins AGW propaganda. I am also surprised that Holton, as far as I know, did not speak out against CAGW based on his deep understanding of atmospheric physics and chemistry.

    See also:
    http://www.atmos-chem-phys.net/4/875/2004/acp-4-875-2004.pdf about Holton

  9. graphicconception says:

    “… there are more of them in a given volume. That makes it more likely that water vapour and co2 molecules in the volume will intercept and absorb photons …”

    Is that true?

    According to Wikipedia (so it must be right!):

    “As another test of the reliability of the system, the long brass tube was cut to about a quarter of its original length, and the exact same quantity of gas was released into the shorter tube. (Thus the shorter tube will have about four times higher gas density). It was found that the percentage of radiant heat absorbed by or transmitted through the gas relative to the empty-tube state was entirely unchanged …”

    http://en.wikipedia.org/wiki/File:TyndallsSetupForMeasuringRadiantHeatAbsorptionByGases_annotated.jpg

  10. tallbloke says:

    GC: Welcome, and good question. I suspect it will have something to do with saturation levels, but we’ll await some expert opinion. The open atmosphere is a very different place to the inside of Tyndall’s brass tube. I think he used much higher concentrations of co2 than will ever be found in Nature.

  11. wayne says:

    TB, don’t let that Wikipedia statement fool you. It is exactly correct but by the missing words, it can leave you with so wrong an impression if you are translating into density and pressure. It has nothing to do with saturation.

    The amount of absorption is strictly determined by the mass it passes through. Period. The amount of space that a given mass of gas is spread through (think density) is irrelevant. So tallbloke, in one way, you are thinking correct, there is more mass per unit volume, higher density, near the surface so that is where the most absorption occurs. It is easy to calculate this accurately, integrate the density to get the total mass transversed. But pressure per se has nothing to do with it either, and that is where it is easy to get the wording mixed up. However, in an atmosphere, density closely, but not exactly, tracks pressure so roughly even when speaking of absorption as to pressure, it is roughly correct, but once again, the ruling underlying variable is the mass. Look under the “mass attenuation coefficient” or “mass extinction coefficient” if you want to review the finer details.

    But just because there is more mass near the surface and it absorbs a given amount of energy does not mean it is warms that air more, each molecule get the same fraction of energy absorbed no matter of the density. I’ve seen both you and Stephen speaking and I should have clarified earlier. In my next comment it should become clear to you why you should drop that insistence, it is not correct, and more importantly, is not even needed to explain why our atmosphere is doing just fine and it always will, if Sol will behaves that is.

  12. wayne says:

    I have to agree with Tim Folkerts here, a perfectly insulated column of gases are going to be isothermal. However, I also agree with Q. Daniels, if you heat constantly the bottom by any amount, no matter how tiny that rate, over time the natural DALR will end up it’s final state. The potential temperature gradient will be respected but it takes energy to drive that respect. The same thing would occur if you were to cool constantly the top, removing energy, no matter small the rate of energy being removed, the time to the static state is the variable here.

    Our atmosphere is in a tug-of-war with itself due to water’s properties. Venus and Jupiter’s atmospheres show little of this state-change effects. The condensation and evaporation of water are doing exactly the opposite in energy as to my example above, it is cooling the bottom and warming the top. But it can never reach anywhere close to isothermal due to the cooling at the surface that decreases the evaporation that is cooling it’s own source! Another way to put it, water vapor has it’s own negative feedback moving the DALR back toward isothermal due to the temperature difference between the bottom and top. The DALR wants either, one, the top much colder or two, the bottom much hotter, but water is countering that tendency by cooling the bottom and warming the top, but this is naturally limited due to the very cooling it is performing.

    That is also why the SST always tends to top-off below ~33°C. At that particular temperature, the cooling rate at that temperature must reach the point that it fights further rise in temperature due to the cooling the evaporation is performing to it’s own source. Another negative feedback it seems.

    Without water evaporation and condensation, this world would be between 309‹K› and 325‹K› at the surface according to the DALR and the point vertically where you choose to think a radiation-to-space balance would occur.

    This also seems why my coffee also so quickly cools down to just warm (~33°C) and then seems to stay there… lukewarm. ;)

  13. michael hart says:

    “The open atmosphere is a very different place to the inside of Tyndall’s brass tube.”

    That was my first thought. My, somewhat limited, understanding of detection of EM-radiation is that as the EM wavelength(s) being measured increase, it becomes increasingly difficult to separate signal from thermal noise. (i.e. thermal radiation from the brass walls of Tyndall’s tube)

    For many years I never fully understood that this was why so many modern sensitive detectors have to be supercooled in liquid helium.

  14. tallbloke says:

    Wayne, thanks for your comments.

    “just because there is more mass near the surface and it absorbs a given amount of energy does not mean it is warms that air more, each molecule get the same fraction of energy absorbed no matter of the density.”

    Sure, but as I pointed out to Tamsin, the ensemble has a heat capacity. And a denser ensemble of a particular gas will have a higher heat capacity than a less dense one per unit volume. Whether it will get hotter will be a function of how efficiently the energy is spread from the photon absorbing molecules to the non absorbing ones, compared to how quickly the ensemble loses energy to its surroundings. As the air gets thinner at altitude, more energy is lost compared to energy shared. That will affect the bulk temperature or average-temperature-per-molecule if you want to think in molecular terms.

    Heat loss from your coffee slows its rate as it approaches the ambient temperature of the room because it is nearly receiving as much energy as it is losing.

  15. Stephen Wilde says:

    Think mass, gravity and energy supplied.

    Nothing else matters.

    If anything else tries to disturb the temperature (or more accurately energy content) derived from those 3 characterisatics alone then all one sees is a change in circulation adjusting the flow of energy throughput to keep top of atmosphere radiative balance stable.

    The stabilisation process involves the switching of energy to and fro between KE and PE and that is what determines temperature since only KE registers on sensors as temperature.

    The switching to and fro between KE and PE is achieved by expansion and contraction.

    All else is chaff.

  16. tallbloke says:

    Stephen: If Makarieva et al are correct, then it is the height that water vapour ascends to and its density distribution in the atmosphere which does most of the ‘switching to and fro’. Which is why I think my plot of specific humidity vs solar activity levels is important in proving what the main driver of the system’s variability is.

    As Peter Berenyi pointed out on Judy Curry’s site, the molecular PE in the latent phase changes of water are a lot stronger than gravity

    Berényi Péter | February 1, 2013 at 12:53 am | Reply
    “We have described a new and significant source of potential energy governing atmospheric motion. Previously, the only such recognised energy source was the buoyancy associated with temperature gradients.”

    OMG. Is this piece of 19th century physics new in this field? Gravity is a weak force, molecular forces are strong.

    Moving water into the gas phase, 1 micron away from the surface of droplets (evaporation) needs the same amount of work required to lift it to a height of 230 km above Earth’s surface. In case of ice crystals (sublimation) it is 264 km. These values are more than an order of magnitude higher, than tropospheric thickness, therefore potential energy storage in the atmosphere is dominated by the water cycle.

    Also, mass of water evaporated (and recondensed) annually is roughly the same as that of the entire atmosphere. Most of it (~90%) never reaches the surface, but re-evaporates in mid air. Atmospheric distribution of water is extremely non-uniform on all scales.

    Back-of-the-envelope calculations do have their merit.

  17. Stephen Wilde says:

    Rog.

    Within the troposphere that is right.

    The mechanisms in the higher layers are different but one can subsume them all into my single adiabatic loop.

    Makarieva et al are looking at the main mechanism in the troposphere (the water cycle) but it is only part of a larger picture.

    Where they lose my support is in giving undue weight to the effect of forests as compared to the permanent climate zones and the rainfall patterns that preceded the growth of the first forests.

    Also the phenomena they describe and quantify are already well recognised once one gives equal weight to evaporation and condensation as mirror images of each other.

    The apparent emphasis on condensation is unhelpful but I think they need to do that in order to propose that forests are a driver of rainfall rather than a consequence of rainfall.

    To give forests the power they desire they need to supplant the evaporative power of the oceans as the main driver so they place the emphasis on condensation above forests instead.

    To get forests to be the main driver they have to say that forests cause lower surface pressure which pulls air in from the oceans to cause rainfall. That is why they focus on the contraction of air when vapour condenses out.

    In reality it was evaporation that caused the pressure reduction but they need it to be the condensation but you can’t reduce pressure from evaporation then reduce it again from condensation.

    The truth is that evaporation reduces pressure by increasing volume and condensation increases pressure by reducing volume.

    That is evident from the fact that the original volume after condensation will include the oiginal content plus additional content pulled in from the surroundings. It must give a higher surface pressure not lighter.

    The whole paper is designed to give forests the driving power and then they have to make the next logical leap and say that all deserts or dry areas could be afforested by their proposed process. Hence the idea of making flat, low, dry Australia wetter by just planting trees.

    I’m afraid I don’t buy that.

  18. tallbloke says:

    Stephen: The important part of their paper thermodynamically is the part where they explain how the imbalance in the energy required to move moist parcels up and drier parcels down gives the net power which drives the circulation of around 4W/m^2. If there were no forests, there would be less power available to drive circulation. That would make the surface more vulnerable to extremes in solar variation, because there would be less power to alter the circulation to mitigate the variation in the external driver. Or t least I think that’s what they’re saying, I’m still studying it.

    We should continue this on one of the Makarieva threads. I shouldn’t have raised it here.

  19. Hans Jelbring says:

    Stephen Wilde says: February 3, 2013 at 4:27 pm
    “The switching to and fro between KE and PE is achieved by expansion and contraction.
    All else is chaff.”

    Agree, but to avoid misunderstanding the ADIABATIC condtion means that total energy in any mass unit is constant which is seen in nature when the (dry) adiabatic temperature lapse rate is observed to be approximately -9.8 K/km (-g/Cp)) which is common in the lower atmosphere most sunny afternoons above land areas. This physical state is spontaneously reached by the atmosphere according to the second law of thermodynamics applied to energy instead of temperature. Do notice that both adiabatic and nonadiabatic situations (processes) both involve expansion and contraction (as a function of elevation).

    Another way to put it is that any vertical motion of a closed air mass in nature will always involve expansion and/or contraction and these phenomena has little value to descriminate between the type of energetic process at hand.

  20. Hans Jelbring says:

    tallbloke says: February 3, 2013 at 4:40 pm

    You are showing curves with a correlation over sun spot cycles and I don´t doubt them and that they mean something but it is a big questionmark of what interpretation to favour.
    The fit is far from perfect and I don´t know if these values are global or not. Much causion is needed.
    Anyway, these curves are close to worthless when judging what dominating physical processes are acting in nature since such ones are always momentarily and have to be found fairly often.

    The impact of water vapor condensation and evaporation (energy exchange) has been well described quantitatively by James R. Holton relating to air masses that are ascending or descending. The impact on condensation on lapse rate is limited both in space and time and can be very well described by models which are supported by obseervational evidence.

    One way to increase water vapor in the atmosphere (at constant temperature) is to increase wind speed over ocean surfaces. Another way would be a decrease of IR radiation to space for any reason. There are many hypothetical options that can be advocated.

  21. tckev says:

    Starting with the statement “At the heart of them [Climate models] are basic laws of physics, like Newton’s laws of motion and the laws of thermodynamics” is pushing credulity. Basic laws of physics have been perverted in the continuing effort to prove the model’s have any legitimacy.

    Also it the basic departure from reality with models that are reliant on a flat planet model, over homogenized temperature data, and an invariant solar output.

    Twisting the data within twisted laws of nature will somehow show us an insight to how the climate works. I don’t think so.

  22. AlecM says:

    There people haven’t a bloody clue. There are 13 mistakes in the physics, three of which are so elementary as to be cringe making.

    The worst is to imagine that a pyrometer with the temperature signal converted to an ‘energy flux’ by S-B gives a real energy flow.This allowed Houghton to get away with his three mistakes – you can’t use the 2-stream approximation at heterogeneous boundaries, the earth is not a black body emitter The atmosphere is not a grey body – the atmospheric window folks!

    Pyrgeometers predict a potential flux if the emitter(s) in the view angle were to radiate to a sink at absolute zero. In the CO2 band the surface emits no IR because of simple standard radiative equilibrium Kirchhoff worked out.

    As for Tamsin, she stopped me pointing out on her blog that ‘back radiation’ does not exist and any scientist who claim so is no scientist. As an engineer who is an expert on heat transfer , i can say it because I have measured all there is from scratch, including GHGs which physics was invented by people i knew in the past.

    No direct thermalisation, Taking account of convection and evapo-transpiration, the Earth’s operational emissivity = 0.16. No Down radiation at ToA except from the stratosphere. Indirect thermalisation is at clouds which cool because of the asymmetry as GHG thermal radiation is converted the grey body and AW to space. Exaggeration of GHG warming by 6.85.

    What else, Oh Yes – the OLR CO2 dip comes from 260 °K, just above cloud l4vel because it is preferable for excess GHG thermal IR to pseudo-diffuse to space than thermalise at clouds.

    Sagan’s aerosol optical physics is wrong because be believed van der Hulst’s empirical data means some great equation.

    These people have made just about every mistake possible and are supremely arrogant about it. Sack 2/3rd for retraining as shelf stickers.

    PS the key factor is the AW, There is no GHG blanket. There can be no CO2-AGW. All of this is provable theoretically or experimentally. The real GHE is the reduction of operational emissivity by the GHGs, plus cloud effects. At night it’s very different and you get bidirectional radiation in and out of the AW.

    PPS lapse rate gives ~24 K warming, the real GHE is <=9 K.

    PPPS Tyndall’s experiment proved absorption of IR but not where it is thermalised. That’s at the walls, as it is with the PET bottle experiment. Nahle’s Mylar balloon work proved that. Anyone who imagines the dribs and drabs lost argument is a nincompoop because of Gibb’s Principle of indistinguishability, LTE. and quantum exclusion. Look up the physics of the CO2 laser for proof.

    PPPPS – A radiometer in the atmosphere measures twice the CO2 emissivity the same radiometer would measure on a satellite – self-absorption folks, standard in analytical spectroscopy.

  23. Q. Daniels says:

    TB,

    I mis-remembered, and shifted the value left two places.

    http://en.wikipedia.org/wiki/List_of_thermal_conductivities

    Air is at 24 mW/m*K

    Adiabat is 9.6k/km, or roughly 0.01 K/m

    If the adiabat were maintained by thermal transport without convection, the air would be transporting 0.25 mW/m^2.

    I believe TimF indicated he got a similar result.

  24. tallbloke says:

    QD: I make that 0.25W not 0.25mW ?

  25. Q. Daniels says:

    TB, conductivity is 0.024 W/m*K. I wrote the value in milli-watts.

    Unless there is air movement, it’s a pretty good insulator.

  26. tallbloke says:

    OK, So that’s the conduction only, no radiation or convection value – right?

  27. AlecM says:

    1981_hansen_etal.pdf shows how Houghton’s incorrect physics was used to create the myth that the GHE = lapse rate warming. Lapse rate is an adiabatic, virtual work computation, apart from relative humidity independent of any first order GHG property except CP, similar for GHGs and non GHGs.

    As dry lapse rate is fixed at g/CP = 9.8 K/km, there can be no Lapse rate GHE in dry areas. Moist lapse rate can fall to ~5 K/km so greater relative humidity increases tropopause height, IR absorption and cloud cover, increasing the GHE.

    Therefore, to state all LR warming is the GHE is incorrect; the only correct deduction is that the flat-disc model ‘real GHE’ + LR warming ~33 K. The bottom line is that this model is only plausible so long as you can juggle the following balls all the time.

    1. Using the 2009 Trenberth Energy Budget, the clear sky atmospheric greenhouse factor from Ramanathan = 390 W/m^2 – 238.5 W/m^2 = 157.5 W/m^2, has in it just 23 W/m^2 real IR warming. The rest of it is imaginary; it comprises the 333 W/m^2 back radiation you add to net surface IR to balance the two-stream requirement at the surface/atmosphere boundary minus the |OLR| down from ToA to do the same at ToA. (the Met Office people argue this is needed because Kirchhoff’s Law of Radiation must apply at ToA, they’re wrong as only the stratosphere IR does this). This gives 94.5 W/m^2.

    2. To this you must add the 40W/m^2 atmospheric window IR which, because it is generated at the Earth’s surface, cannot be included DOWN from ToA. Hence the IR absorbed in the lower atmosphere is exaggerated by 157.5/23 = 6.85 times thus the imaginary positive feedback.

    3. These dorks forget the most basic of radiative thermal equilibrium requirements which is that only net radiative fluxes can do thermodynamic work. This is Maxwell’s Equations via Poynting and trumps everything else. The near black body thermal 15 micron CO2 emission from the lower atmosphere annihilates the upward IR from the surface in the same wavelength interval so there can be virtually no CO2-AGW.

    4. Because of this, CO2 increase has no ability to shift dry lapse rate to moist lapse rate giving the positive feedback. Therefore the Houghton – Hansen – Ramanathan- Trenberth construct fails.

  28. AlecM says:

    Correction: 396 W/m^2 not 390 W/m^2

  29. tallbloke says:

    Alec M: Thanks for fleshing out your first comment. Much easier to see where you are coming from now. I agree that net flux is the important consideration. So given the low value of the actual IR effect, do you agree the gravito-thermodynamic considerations I outlined might be doing quite a lot in comparison?

  30. AlecM says:

    LR warming has to be >24 K on the Flat Earth model.

    Real GHG <9 K

  31. tallbloke says:

    Still no response at Tamsin’s place. Guess I got ‘em thinking. :)
    Either that or they’re not into science communication after all. :(

  32. AlecM says:

    The zero response from Tamsin is very interesting. You must compare this with Curry’s blog which has welcomed the heretics like me who have torpedoed the ‘consensus’ by showing how the GCMs have been used as a carrier for junk heat generation and heat transfer.

    And what makes this very interesting is that I keep on finding yet more critical science not considered by the IPCC. Thus indirect thermalisation at clouds of pseudo-diffused 15 micron CO2 IR above the level compatible with local thermodynamic equilibrium means a transfer of energy in the OLR from that band to the atmospheric window.

    This is a powerful form of negative feedback which is not yet measured. What’s more, the ~28% of the IR from the Earth’s surface not switched off by annihilation of the opposing Planck irradiation functions, heads off to space to combine with the cosmic microwave background in clear skies yet is intercepted by clouds.

    So you have a cooling mechanism, AW to space working at the 4th power of the surface temperature and when it cools too much, clouds form and stop it from working.

    To a engineer like me this is a beautiful proportional control system of which the IPCC is totally and irresponsibly oblivious. What did these people study as undergraduates? Was it Jack and Jill do Stefan Boltzmann?

  33. tallbloke says:

    AlecM: Have a look at Ned Nikolov’s treatment of the ‘flat Earth’ application of the S-B Eq here:
    http://tallbloke.wordpress.com/2012/05/01/ned-nikolov-implications-of-diviner-results-for-the-s-b-standard-equation/

  34. AlecM says:

    I agree with the premise that the flat earth model GHE is wrong. However, this does not take away from the fact that the Hansen et al use of the claim that the GHE = lapse rate warming is junk science and that you prove it by showing CO2-AGW from surface IR ‘trapped’ by CO2 in the atmosphere cannot happen because of standard radiative equilibrium physics.

    As for the secondary effects, e.g. more thermal CO2 IR taking a bigger bite out of the OLR, it’s given back in r=the AW!

    [Reply] I still haven’t worked out what your AW abbreviation means. Please write our r=AW in words

  35. AlecM says:

    AW is ‘Atmospheric Window’. This is the range 14 to 8 microns, 1250 to 715/cm, in which IR absorption is confined to O3 and trace gases. this part of the story has been missed by the IPCC. 28% of the net IR heads to space in clear skies and this is why day time desert temperatures are limited even though the boundary layer will stop most IR outside the AW.

    At night the AW continues to allow heat loss which is why you can get bidirectional radiative heat transfer. For an atmosphere at 25 °C, the desert will cool to -13.5 °C before you can get radiative thermal equilibrium hence the Bedouin make ice in pits.

    In humid areas you get fogs, dew and ground frost. If the ‘GHG blanket’ worked as claimed, you could not get these meteorological phenomena!

  36. AlecM says:

    Error; atmosphere at 15 °C gives -13.5°C for radiative equilibrium.

  37. tallbloke says:

    AlecM: Thanks, should have realised AW = atmospheric window. We all have different shorthands where we have these conversations.

    We will be having a thread on the Radiative theory and what back radiation is and is not very soon, so don’t miss it.

  38. Trick says:

    tallbloke 2/4 4:08pm – Looking at the 5/1/2012 post you link….

    Link note 2) theory & practice being incomparable as noted can be improved to compare apples and apples by using the same theory eqn. as for T~255K using S=1362.7, surface e=1.0 (~L&O rounded up from say .96 give or take), albedo =0.3, atm. emissivity=0.0. Then substituting in with global spatial and temporal sampled atm. emissivity of 0.793 (Trenberthian number) find resulting theory emission temperature (Te) = 288.3K can be used apples to apples for subtraction (though precisely better to work BB stuff with W/m^2 then convert to K). The measured global avg. T=287.6K as noted then may not exist locally anywhere at any reasonable time but gives a sense that the theory is predicting a sampled avg. close to earth reality (the avg. shoe fits a lot of feet).

    The discussion of removing the atm. completely is always a problem in 33K provenance discussion; this thumb rule level theory works way better keeping planetary atm. present but playing around with the surface & atm. emissivity values both of which are pretty well measured. Can play with other values too, like insolation and albedo, just keep them small in the big picture. “Small” is not precise of course but playng around can sort of bracket “small”.

    Simple rules from perturbation theory means must keep them small or the whole system needs remodeling or resetting to initial conditions after a “crash”. I see many complain this thumb rule 33K is terrible, well, yeah, if you give it a huge perturbation like a thought exp. removing the whole atm., for sure it is – that is too big a perturbation to make sense for Earth but not its moon.

    Keep the “kicks” (perturbations) to a modeled stable dynamic system (or even unstable system like a helicopter in flight) small and I’ve learned a lot about the nature of the dynamical system no matter the system I’m “kicking”. Sort of like the round pebble on the hill, don’t kick it so hard it descends to the valley in a much different state of stability. Kicking system around a little one might learn something about its stability (mass, gravity well, friction, flyability, earth LTE et. al.).

    tb – 2/4 7:27pm – Oh boy, reserve some cloud space for that one, ha.

  39. Hans Jelbring says:

    Posted at Tamsin Edward´s site some miunutes ago. The comment is awaiting moderation.

    Dear Dr Edwards,

    Since we have similar education I am glad to confirm that you are describing
    a virtual reality when referring to the highly complex NASA model and
    General Circulation Models often mentioned in the IPCC reports. The real
    question is if there is any value at all using them beside at very short
    time scales.

    To use them for “predicting” the future is like entering the world of Alice
    in Wonderland. This is one reason why their output is called “projections”
    among knowledgeable people and not predictions. I will try to justify my
    statement in a way easy to understand for anyone with a little education in
    maths or gambling.

    I think you would agree that any model rests on a number of assumptions
    where each one has a chance (p) to be correct that is between 0 and 100%.
    Assume that a GCM rests on 50 such assumptions. If any single one of them is
    really bad and p = 0 the model is useless (at least for long term
    forecasts). The weakest link in the logical chain decides the quality of the output.

    Let´s make the claim that all of the basic assumptions and laws have p = 99%
    or alternative3ly 90% chance to be valid as an average. The chance that a long term prediction P will be correct is then approximately P = p^50

    Consider two cases:
    I p(0.9) = 0.9 will mean that the end result P(0.9) = 0.0051 The model will
    be correct about 5 times our of 1000 which means that it is useless as a
    prediction tool.
    II p(0.99) produces P(0.99) = 0.60 which means that the end result is
    correct about 60 times of 100 which is not good enough. A percentage of
    0.95 ought to be achieved to reach a scientific standard.

    However, there is no scientific support that the impact of anthropogenic carbon dioxide emissions
    (the unproven greenhouse effect from carbon dioxide) has the effect claimed
    by the GCM models. Let´s be generous and estimate that the chance
    of this assumption to be correct is 10%. This value should actually be lower IMO since
    no one has verified its impact in nature despite 20 years of hard work among
    scientists.

    Then, there are 49 more assumptions that can and should be discussed separately before
    putting any faith in long term climate models. Consequently, IMO, the chance that
    GCMs have a predictive capacity is approximately zero. Any result that is claimed to have a scientific value has to be verifiable. If that´s not possible or has been ignored the produced result is simply not reaching a scientific standard. Colorful animations such as the one made by supercomputers at NASA doesn´t change that fact. Such ones can serve the purpose of general information at high school level but not more. It is sad when qualified scientists use them as more than guidelines and expecting them to influence prominent decision makers in our societies.
    Best

    Hans Jelbring
    Ph.D. Climatologist

  40. tallbloke says:

    Well said Hans, It’ll be interesting to see if Tamsin answers your comment or mine first…If she answers either of them.

    [UPDATE] I see Tamsin has approved your post. Maybe by having most recent comments first she’s hoping no-one notices ours in a few days. ;)

  41. Tim Folkerts says:

    QD says: “If the adiabat[ic lapse rate] were maintained by thermal transport without convection, the air would be transporting 0.25 mW/m^2.”

    Yes, that sounds like the same number I got. That implies that
    * 0.00 mW/m^2 –> 0K/km lapse rate (isothermal!)
    * 0.05 mW/m^2 –> 2K/km lapse rate
    * 0.10 mW/m^2 –> 4K/km lapse rate
    * 0.15 mW/m^2 –> 6K/km lapse rate
    * 0.20 mW/m^2 –> 8K/km lapse rate
    * 0.25 mW/m^2 –> 10K/km lapse rate
    * 0.30 mW/m^2 –> 10K/km lapse rate
    Yes, that the last one is still 10 K/km. Up to 0.25 W/m^2, only conduction will occur, and the lapse rate would be proportional to heat flow. But above 0.25 W/m^2, convection can and will kick in, limiting the lapse rate to no more than ~10 K/km. And since the average upward flow of energy is WAY larger than 0.25 mW/m^2, the average lapse rate will stay pegged pretty close to 10 K/km. (This all ignores condensation and radiation, which would adjust the numbers a bit for a moist atmosphere with GHGs.)

    Alec supposes: ” this part of the story [the Atmospheric Window] has been missed by the IPCC.
    Why would you assume that? The Atmospheric window is prominently displayed on the Trenberth diagram, so clearly people in the IPCC know it exists.

    “28% of the net IR heads to space in clear skies …
    That sounds about right. But about 2/3 of the globe is covered by clouds which completely block the atmospheric window, so only about 2/3 of that 28% = ~ 10% = ~ 40 W/m^s escapes directly from the surface to space, which is what Trenberth estimates in his paper.

    “Because of this, CO2 increase has no ability to shift dry lapse rate to moist lapse rate …
    True, but what an increase in CO2 *can* do is to raise the location from which the IR escapes to space. With more CO2, the “TOA” will be a little higher. Suppose enough CO2 was added to raise the TOA by just 100 m (for the 14-16 um CO2 band). This will mean that the CO2 that radiates to space will be about 1 K cooler than before (due to the lapse rate & the 100 m altitude increase), and hence will radiate a little less IR than before, messing up the previous balance. The surface (and the rest of the atmosphere) would have to warm up a little to emit a little extra IR to restore the balance.

  42. Q. Daniels says:

    Tim Folkerts wrote:

    An equilibrium column WOULD be isothermal according to the laws of thermodynamics — so that is a perfectly reasonable thing to think.

    Do you have any empirical evidence to back this up?

    I’ve been trying to replicate this, and having no success.

    TB: That’s just conduction. Convection and Radiation are both many orders larger.

  43. tjfolkerts says:

    “Do you have any empirical evidence to back this up?”
    Well, this is the Zeroth Law of Thermodynamics. The Zeroth Law has been tested and accepted innumerable times. If each meter of the column is in thermal equilibrium with the next, then they are all in equilibrium. If they are all in equilibrium, they are all the same temperature.

    Actually confirming this with an experiment is a challenge, since even 1 mW/m^2 of heat flow is plenty to set up a significant temperature gradient.

  44. AlecM says:

    Tim Folkerts: I have been through the various arguments used to support the consensus and raising the tropopause by increased [CO2] is the basis of the IPCC scam. However, it is predicated on other assumptions, pre-eminent being direct thermalisation of ‘trapped CO2 band IR from the surface’.

    There isn’t any such IR,can’t be any. You get this by applying standard radiative thermal equilibrium physics which assumes that only the net IR can do thermodynamic work, and there is next to zero net CO2 band IR from the surface.

    This is a fact. There is no way round it. The IPCC get it by breaching Maxxwell’s Equations and there is no evidence of any CO2-AGW.

    Ah, people might argue, what about the dip in the OLR as CO2 rises? That energy is transferred to the atmospheric window via clouds.

    In short there is a plethora of negative feedbacks that are ignored to maximise the scare story.

  45. tallbloke says:

    “The Zeroth Law has been tested and accepted”

    “Actually confirming this with an experiment is a challenge”

    Lol.

    The zeroth law is not broken by contiguous bodies with a gradient running through them. It’s a false argument. And as well as Graeff’s experimental evidence proving that, a contributor has replicated it and sent me results. We’ll be publishing it soon.

  46. tjfolkerts says:

    The zeroth law is not broken by contiguous bodies with a gradient running through them.
    I would challenge you to go to any university and get any physics professor to agree with you!

    Graeff did some interesting work, but I am still skeptical. Microwatt heat sources would be enough to set up the observed gradients in his experiments — which is exactly why I said these experiments are challenging. A temperature gradient in a column of gas at equilibrium (where different gases have different gradients) would contradict the textbook understanding of both the Zeroth & the Second Laws of thermodynamics.

  47. tallbloke says:

    It seems Tamsin couldn’t work out how to reply to my question. She appears to have deleted it from her blog instead, along with Hans Jelbring’s. Not a very auspicious start to a ‘science communication’ career.