Tuesday, February 25, 2014

Why Earth's climate is self-regulating & independent of man-made CO2

The atmosphere is a self-regulatory, homeostatic mechanism that has maintained Earth's surface temperature within a remarkably stable range over millennia. The primary reason is due to the fact we live on a water planet which automatically counteracts any temperature excursions hot or cold. The basic mechanism is:

1. If the surface warms, this causes increased evaporation and water vapor which:

a. increases clouds, which reflects more sunlight to space [increased albedo], which decreases solar radiation at the surface and causes cooling to restore balance.

b. increased water vapor increases the heat capacity of the atmosphere [Cp], which decreases the natural adiabatic lapse rate = dT/h = -g/Cp [g = gravity, Cp=heat capacity, h=height, dT change in temperature]. A decrease of the lapse rate causes cooling of the surface by shifting and tilting to the left the lapse rate temperature profile shown on the figure below:



This shift and tilt of the lapse rate temperature profile to the left [cooling] decreases the mean radiating height of the atmosphere. Since the atmosphere is warmer at this decreased mean radiating height, more infrared radiation will be emitted by greenhouse gases to space, thus cooling the planet to restore balance. Note, there is no term for radiative forcing from greenhouse gases in the lapse rate formula and radiative forcing from greenhouse gases does not affect the lapse rate. Therefore, man-made CO2 has a trivial influence on climate.

The opposite is true if the surface cools:

2. If the surface cools, this causes decreased evaporation and water vapor which:

a. decreases clouds, which reflects less sunlight to space [decreased albedo], which increases solar radiation at the surface and causes warming to restore balance.

b. decreased water vapor decreases the heat capacity of the atmosphere [Cp], which increases the natural adiabatic lapse rate = dT/h = -g/Cp [g = gravity, Cp=heat capacity, h=height, dT change in temperature]. An increase of the lapse rate causes warming of the surface by shifting and tilting to the right the lapse rate temperature profile shown on the figure below:



This shift of the lapse rate temperature profile to the right [warming] increases the mean radiating height of the atmosphere. Since the atmosphere is colder at this increased mean radiating height, less infrared radiation will be emitted by greenhouse gases to space, thus warming the planet to restore balance. Note, there is no term for radiative forcing from greenhouse gases in the lapse rate formula and radiative forcing from greenhouse gases does not affect the lapse rate. Therefore, man-made CO2 has a trivial influence on climate.

Related: Please see Willis Eschenbach's post today at WUWT demonstrating clear observational evidence that these emergent thermodynamic phenomena control temperature and the climate, not radiative forcing.

Notes:

1. The surface temperature, as well as the entire atmospheric temperature profile, is entirely explained by solar insolation plus the behavior of adiabatic gases in a gravity field, which establishes the wet and dry adiabatic lapse rates.

2. The dry adiabatic lapse rate equation: dT/h = -g/Cp [g is gravity, Cp is heat capacity of the atmosphere] does not have a term for radiative forcing and is independent of radiative forcing.

3. Addition of water vapor increases the heat capacity Cp, which causes a decrease in the lapse rate, as is observed: the dry lapse rate is much steeper than the wet. A decrease in the lapse rate causes a cooler surface.

4. The entire 33K “greenhouse effect” is entirely explainable by the average adiabatic lapse rate i.e. the observed average lapse rate = 6.5K/km * 5 km = 33K. The 255K equilibrium temperature with the Sun at the TOA + 33K due to the lapse rate sets the surface temperature at 288K or 15C.



Illustration of an electrical circuit analogy to radiative-convective equilibrium in a planetary atmosphere. Pressure and heat capacity set the resistance [opacity] to infrared transmission illustrated as the resistor Rc above. GHGs set the resistance [opacity] to infrared transmission illustrated as the resistor Rt above. As noted, "Resistance Rc corresponds to convection "shorting out" the radiative resistance Rt, allowing more current [analogous to heat in the atmosphere] to escape. If the resistance [IR opacity] of Rt increases due to adding more greenhouse gases, the resistance [IR opacity] of Rc will automatically drop to re-establish balance and thus the current through the circuit remains the same, and analogously, the temperature of the surface of the planet remains the same and self-regulates. Source
5. The huge heat capacity of the oceans, 1000 times greater than the atmosphere, also stabilizes global temperature. The tail [atmosphere] does not wag the dog [oceans]: The primary heat transfer sequence is Sun to oceans to atmosphere to space. IR from greenhouse gases has no effect on ocean temperature, because IR can only penetrate water a few microns to cause evaporative cooling of the ocean 'skin' surface, among other reasons. 

59 comments:

  1. Here's how the dry adiabatic lapse rate is derived from basic physics, and is completely independent of radiative forcing:

    from a comment on this blog by a PhD physical chemist:

    Consider a vertical gas column containing a finite and constant specific energy level (U, J/kg) that is isolated from its surroundings (no input/output of energy or mass) but which is in a gravitational field. The column will in time reach equilibrium with respect to internal specific energy but the temperature will not be uniform. At static equilibrium (adiabatic equilibrium where no macro motion exists), internal specific energy (U) is composed of both thermal energy (the energy due to molecular motion) and potential energy (the energy due to
    position). The latter has to exist in a gravitational field. Thus, according to the first and second law of thermodynamics, the specific internal energy (U) for any mass parcel in the air column has to be constant and can be expressed as a sum of the thermal and potential energies. This law (expressed as specific energies) can be written:

    U = CpT + gh or upon differentiation dU = CpdT + gdh (1)

    where “CpT” is the enthalpy (or thermal energy) per mass unit, “g” is the gravitational acceleration, “h” is the vertical height and “gh” is the potential energy per mass unit.
    At static equilibrium dU = 0 and equation (1) becomes;

    CpdT + gdh = 0 (2)

    Thus, according to the first and second laws of thermodynamics, for any given difference in altitude (height) the increase in specific potential energy (gdh) must be offset by a corresponding decrease in thermal energy (CpdT) and a corresponding decrease in temperature. Thus in a gravitational field an atmosphere in equilibrium must have a non- isothermal decreasing temperature distribution with altitude. This is true in an isolated air column and this basic physical phenomenon exists independent of any input/output of other energy sources such as ground temperature, convection, radiation, convection, etc. And of course equation (2) can be rewritten as:

    dT/dh = -g/CpT = -9.8 K/km

    which is a temperature profile often observed in our atmosphere on a daily basis. This static temperature lapse rate (in this model atmosphere) is identical to the dry adiabatic lapse rate theoretically derived in Meteorology for a convective adiabatic air parcel. In both situations it is solely a function of the magnitude of the gravitational field and the heat capacity of the atmospheric gas, and nothing else. And this relationship aptly describes the bulk of the 33ºC so-called “Greenhouse Effect” that is the bread and butter of the Climate Science Community.

    It is remarkable that this very simple derivation is totally ignored in the field of Climate Science simply because it refutes the radiation heat transfer model as the dominant cause of the GE. Hence, that community is relying on an inadequate model to blame CO2 and innocent citizens for global warming in order to generate funding and to gain attention. If this is what “science” has become today, I, as a scientist, am ashamed.

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    1. The derivation of the dry lapse rate equation above is then used to determine the 33K "greenhouse effect" as was noted in the post:

      The dry adiabatic lapse rate equation: dT/h = -g/Cp [g is gravity, Cp is heat capacity of the atmosphere] does not have a term for radiative forcing and is independent of radiative forcing.

      3. Addition of water vapor increases the heat capacity Cp, which causes a decrease in the lapse rate, as is observed: the dry lapse rate is much steeper than the wet. A decrease in the lapse rate causes a cooler surface.

      4. The entire 33K “greenhouse effect” is entirely explainable by the average adiabatic lapse rate i.e. the observed average lapse rate = 6.5K/km * 5 km = 33K. The 255K equilibrium temperature with the Sun at the TOA + 33K due to the lapse rate sets the surface temperature at 288K or 15C.

      Delete
  2. For conservation of energy, the mean emission height in the atmosphere must be the level at which the temperature is equal to the equilibrium temperature with the Sun = 255K

    The mean emission height h in the atmosphere is observed to be at about 5km where T = 255K. The temperature profile of the atmosphere is determined by the average lapse rate of 6.5K/km, which determines a temperature of 255K occurs at h = 5km.

    In the lapse rate formula dT/dh = -g/Cp, both dT and h are dependent variables upon the independent variable -g/Cp. Therefore, the mean emission height is determined by changes in the average heat capacity of the atmosphere only, not radiative forcing from greenhouse gases.

    ReplyDelete
  3. A recent paper published in Nature Geoscience finds:

    Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency

    A minimum atmospheric temperature, or tropopause, occurs at a pressure of around 0.1 bar in the atmospheres of Earth1, Titan2, Jupiter3, Saturn4, Uranus and Neptune4, despite great differences in atmospheric composition, gravity, internal heat and sunlight.

    In all of these bodies, the tropopause separates a stratosphere with a temperature profile that is controlled by the absorption of short-wave solar radiation, from a region below characterized by convection, weather and clouds5, 6. However, it is not obvious why the tropopause occurs at the specific pressure near 0.1 bar. Here we use a simple, physically based model7 to demonstrate that, at atmospheric pressures lower than 0.1 bar, transparency to thermal radiation allows short-wave heating to dominate, creating a stratosphere. At higher pressures, atmospheres become opaque to thermal radiation, causing temperatures to increase with depth and convection to ensue. A common dependence of infrared opacity on pressure, arising from the shared physics of molecular absorption, sets the 0.1 bar tropopause. We reason that a tropopause at a pressure of approximately 0.1 bar is characteristic of many thick atmospheres, including exoplanets and exomoons in our galaxy and beyond. Judicious use of this rule could help constrain the atmospheric structure, and thus the surface environments and habitability, of exoplanets."

    http://www.nature.com/ngeo/journal/v7/n1/full/ngeo2020.html
    http://www.nature.com/ngeo/journal/v7/n1/carousel/ngeo2020-f1.jpg


    Therefore, to determine surface temperature of any planet, start from the height of the tropopause at 0.1 bar and using the lapse rate determine the temperature profile down to the surface.

    The surface temperature is thus solely a function of gravity, atmospheric mass, atmospheric heat capacity and has no relationship to radiative forcing from greenhouse gases.

    ReplyDelete
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    1. The mean emission height on any planet will thus be the height at which T determined from the lapse rate is equal to the equilibrium T with the Sun [for conservation of energy].

      Delete
  4. Joseph E Postma says:
    2013/12/09 at 7:04 PM

    Yes that is really really neat about the 0.1 bar thing. Why? Because one thing I’ve always found curious is that, given all the differences in insolation at the surface (Venus has hardly any direct insolation at its ground surface) and other atmospheric differences, if you combine the radiative surface with the atmosphere’s lapse rate, you always calculate the near-surface-air temperature correctly. So if IR opacity is largely dependent simply on pressure, then bang, that defines where the radiative surface is going to be and then it automatically follows what the air temperature at the surface will be given the particular lapse rate. Great stuff.

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  5. Here's the whole paper"

    http://faculty.washington.edu/dcatling/Robinson2014_0.1bar_Tropopause.pdf

    ReplyDelete
    Replies
    1. http://www.lpi.usra.edu/planetary_atmospheres/presentations/Catling.pdf

      Delete
  6. http://arxiv.org/ftp/arxiv/papers/1209/1209.1833.pdf

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  7. Paper written in 1930 corroborates the effect of gravity upon adiabatic gases to establish a temperature profile:

    http://authors.library.caltech.edu/2574/1/TOLpr30a.pdf

    Richard Tolman wrote a paper, “On the weight of heat, and thermal equilibrium in general relativity”. In it, he derives first a classical approximation and then the relativistic solution to the differences of temperature with distance from the center of a self gravitating gas in thermal equilibrium. In the conclusion he writes:

    “Qualitatively, the increase in equilibrium temperature which was found to accompany decrease in gravitational potential, may be regarded as due to the necessity of having a temperature gradient to prevent the flow of heat from places of higher to those of lower potential energy; and quantitatively, a first approximation to the magnitude of this temperature gradient was obtained by modifying the classical thermodynamics merely by ascribing to each given intrinsic quantity of energy the right additional quantity of potential gravitational energy.”

    He then goes on to note the necessity of a more accurate formulation to account for relativistic effects.

    He goes on, in his final paragraph to write:

    “This discovery of a dependence of equilibrium temperature on gravitational potential must be regarded as something essentially new in thermodynamics, since uniform temperature throughout any system that has come to equilibrium has hitherto been taken as an inescapable part of any thermodynamic theory. The new result hence has a very considerable theoretical interest, and even though the effect of gravitational potential on temperature may usually be extremely small the result may sometime be of experimental and observational interest.”

    ReplyDelete
    Replies
    1. New in 1930?

      What about Loschmidt's gravito-thermal effect which he postulated in 1870.

      A.

      Delete
  8. Dr Curry: "The linear [IPCC] model, with climate change radiatively forced...unlikely to improve climate understanding" feedly.com/k/1lsVaYr

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  9. Please see this new post for many additional papers which support the fact that the entire 33K "greenhouse effect" is solely due to gravity, atmospheric mass, solar insolation, and is independent of "radiative forcing from greenhouse gases."

    http://hockeyschtick.blogspot.com/2014/03/why-ideal-gas-law-gravity-atmospheric.html

    ReplyDelete
  10. In the light of the above you may find this helpful:

    http://www.newclimatemodel.com/the-gas-constant-as-the-global-thermostat/

    Stephen Wilde

    ReplyDelete
  11. For a lot more detail see here:

    http://www.newclimatemodel.com/the-ignoring-of-adiabatic-processes-big-mistake/

    from December 2012

    Stephen Wilde

    ReplyDelete
  12. http://tallbloke.wordpress.com/2012/01/16/the-gravity-of-some-matter/#comment-14236

    http://tallbloke.wordpress.com/2012/01/04/the-loschmidt-gravito-thermal-effect-old-controversy-new-relevance/#comment-12990

    ReplyDelete
  13. Just started looking at this site- in notes part 4, 6.5K/km (lapse rate) x 5km = 33K . Why 5 km? What is the significance of 5 km? Thanks!

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    1. Height of the troposphere is ~5-6 km

      The lapse rate only applies to the troposphere, therefore multiply height of troposphere * average lapse rate = 33K greenhouse effect

      Delete
  14. The Robinson & Catling model puts CO2 in its place. It is not the "Magic Gas" responsible for the "Greenhouse Effect" (Arrhenius,1896).

    http://diggingintheclay.wordpress.com/2014/04/27/robinson-and-catling-model-closely-matches-data-for-titans-atmosphere/

    While I agree with MS on most things the 255 K "Equilibrium Temperature" for Earth is incorrect. It is based on good mathematics spoiled by incorrect assumptions about our planet's surface.

    A more realistic value would be 201 Kelvin. That would be 197 K (the average temperature of our Moon) plus 4 K to allow for a 27 faster rate of rotation.

    http://tallbloke.wordpress.com/2014/04/18/a-new-lunar-thermal-model-based-on-finite-element-analysis-of-regolith-physical-properties/

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    1. Thanks, I also corresponded with Dr. Robinson and he confirmed that the "GHE" is primarily a function of atmospheric mass/gravity and the 0.04% CO2 adds very little mass therefore very little effect on the GHE.

      Delete
  15. convection ends in the tropopause

    http://onlinelibrary.wiley.com/doi/10.1029/2001JD001048/abstract

    ReplyDelete
  16. http://tallbloke.wordpress.com/2014/03/23/challenging-arrhenius-again/

    ReplyDelete
  17. http://tallbloke.wordpress.com/2014/03/11/effective-emission-height/

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  18. stratospheric cooling

    http://www.nature.com/nclimate/journal/v3/n10/full/nclimate1908.html

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  19. emission spectra

    http://www.science-skeptical.de/klimawandel/klimaskeptiker-irrtuemer-welche-argumente-klimaskeptiker-keinesfalls-in-der-klimadebatte-vorbringen-sollten/0011565/

    ReplyDelete
  20. emission spectra

    http://agwobserver.wordpress.com/2010/03/10/simple-observational-proof-of-greenhouse-effect/

    ideal gas calculator

    http://www.ajdesigner.com/idealgas/ideal_gas_law_temperature_equation.php

    tropopause data:

    http://onlinelibrary.wiley.com/doi/10.1029/2006JD007363/abstract

    stratosphere, mesospere trends

    http://onlinelibrary.wiley.com/doi/10.1029/2001GL013633/abstract

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  21. http://www.csc.kth.se/~cgjoh/climatethermoslayer.pdf

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  22. The adiabatic lapse rate does not describe the temperature profile of the atmosphere. It describes the temperature change of a parcel of air that is lifted adiabatically.

    The temperature profile of the atmosphere is driven by the distance relationship between the main heating source (the Earth) and your altitude. Further away is colder.

    If you want another calculation that demonstrates this (and is not referring erroneously to something else) you can use the hydrostatic equation to derive the temperature-dependent pressure profile of the atmosphere, and sub in a near-zero temperature lapse rate. The pressure profile doesn't change remarkably: it converges to a particular exponential decay. As in, the pressure profile can remain about the same as it is right now, even with increasing temperature with altitude.

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    1. The lapse rate absolutely does describe the temperature profile of the atmosphere, dT/dh = -g/Cp

      The temperature profile of the troposphere is approx:

      255K [Equilibrium temp with Sun] + Adiabatic Lapse Rate.

      Start at the middle of mass of the atmosphere ~5.2km where T=255K=Equilibrium temp with Sun=Average emission height

      255 + 5.2km*6.5K/km [average lapse rate] = 288K = surface temperature of Earth

      As shown in this diagram, which also shows temperature profile and pressure as essentially parallel lines within the troposphere up to the radiative/convective boundary/tropopause where P=100 bars.

      Delete
  23. (This is Alexander Coulter, I'm on a different computer sorry.)

    "The lapse rate absolutely does describe the temperature profile of the atmosphere, dT/dh = -g/Cp"

    Just because you use an equation that has a change in temperature over a change in height does not mean that it actually describes the change in temperature of the static atmosphere. It's called the "adiabatic" lapse rate for a reason: it describes a lapse rate during an adiabatic process, i.e. adiabatic lifting. So, it describes the temperature change of a moving air parcel not exchanging heat with its environment.

    There is the adiabatic lapse rate, which is derived from the Poisson relations in an adiabatic transformation. It describes the change in temperature of a parcel of air that undergoes an adiabatic lift (or descent). Then there is the environmental lapse rate, which describes the temperature profile of the atmosphere.

    You should consider two things. The first, consider a 1D atmosphere profile, with the material for an atmosphere "frozen" on the surface of a planet without insolation. This atmosphere will be transparent to IR: it cannot radiate energy away. No greenhouse gases. Now add sunlight at ~390 W/m^2 (a greater value than current insolation, keep in mind). The surface will sublime and warm due to conduction, and warmer less buoyant air will rise adiabatically.

    Since heat loss from radiation is the only way energy can leave the planetary system, the surface of the planet (and the surface air as well because of conduction) will warm until it reaches 288K. This is the blackbody temperature of a body emitting at 390 W/m^2. If gravity is the same as on our planet, and the atmosphere has the same heat capacity, then convection will continue until the environmental lapse rate equals the dry adiabatic lapse rate of -9.8K/km. It will approach this value from an initially *high* rate of temperature change in the atmosphere (say, -30K/km) because we started with a very thin atmosphere that's expanding and rising as it warms. The environmental lapse rate cannot get lower by convection, as anything less (say, -5K/km) would be a stable condition where rising air would just sink back to its initial level.

    When convection stops we have conduction take over. Conduction will always carry heat from high to low: even though you will not get bulk movement of air parcels as through convection, you will end up with warmer air close to the surface transporting heat via conduction to higher layers until an isothermal atmosphere is reached. This is an atmosphere without a temperature gradient, that still has an adiabatic lapse rate, that is still stable.

    It is only by adding absorptivity (adding greenhouse gases) that conduction will NOT carry an atmosphere through to isothermal, because an isothermal but radiatively absorptive atmosphere will lose energy via radiation; and it will lose it to space. So if we take our example atmosphere, and all of a sudden make it absorptive (and thus emissive), the top layers will cool until you reach a height where photons cannot escape any more because of collisions taking away energy absorbed more rapidly than it can be emitted. But you cannot have a top layer that is cold, immediately transform into a warm lower layer: convection will recreate the environmental lapse rate, and the atmosphere will be isothermal above the afore-stated height (at which it can radiate away), and will have some ELR that will approach the ALR depending on how strong of an absorber it is.

    ReplyDelete
  24. (pt 2)
    Second thing you should consider is the derivation of the temperature-dependent pressure profile for an atmosphere. I'll derive it (in this equation, g is negative, as I like to use "up" as a positive direction):

    dp/dz = (rho)*g
    dp = rho * g * dz
    dp = (p / R / T) * g * dz
    dp/p = g/R * 1/T * (dT/dT) * dz
    dp/p = g/R * (dz/dT) * dT/T
    dp/p = g/R * 1/tau * dT/T
    ln(p_z / p_0) = (g / R / tau) * ln(T_z / T_0)
    p_z / p_0 = (T_z / T_0)^(g / R / tau)
    p_z = p_0 * (T_z / T_0)^(g/R/tau)
    p_z = p_0 * ( (T_0 + z*tau) / T_0)^(g/R/tau)

    Here "tau" is the environmental temperature lapse rate. Plug this equation into Excel, and give tau a value that is very very close to zero. And, give it a value that matches the adiabatic lapse rate (~0.0098 K/m). Graph the pressure profiles against each other, and when you do, please explain to me how a nearly isothermal atmosphere could possible correspond to an exponentially decreasing pressure profile.

    (Hint: the equation is of the form (1 + 1/n)^n, which in the limit is 1/e.)

    ReplyDelete
  25. (Still Alex Coulter)

    To actually modify my first part of the previous set of comments: if the atmosphere becomes radiatively absorptive (and emissive), it will begin to absorb radiation and translate that into kinetic motion below the height that will become the new tropopause; this results in warming below the tropopause. More absorbed energy at lower altitudes (higher volumetric concentration of the gases due to higher pressure) means it is warmer below than it is above. That is what helps create the ELR, not necessarily cooling of the upper layers. At radiative equilibrium, the layers above the troposphere should be losing radiation at each wavelength at the same rate they are gaining radiation at that wavelength. It's my understanding that above the tropopause it would be isothermal, and also at the blackbody temperature.

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  26. Maxwell and many others have shown that an atmosphere without GHGs would not be isothermal as you falsely claim.

    http://hockeyschtick.blogspot.com/2014/05/maxwell-established-that-gravity.html

    http://hockeyschtick.blogspot.com/2014/03/why-ideal-gas-law-gravity-atmospheric.html

    ReplyDelete
  27. Do you not know what causes convection? In order to have mass movement of energy in a parcel of air, that parcel of air needs to obtain that energy. How will that parcel obtain its energy?

    • Conduction? I've already established (and Maxwell agrees) that with only conduction, you get an isothermal atmosphere.
    • Radiation? No, because we're working without greenhouse gases.
    • Convection? That is begging the question.

    In a simple atmosphere, convection stops without thermal absorptivity. You can quote Maxwell all you want, but you don't seem to understand what he is saying.

    You still haven't responded to the second part of my comment, too, regarding the pressure lapse rate equation.

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    Replies
    1. Solar radiation heats the surface -> heated air packet rises, expands, and cools via convection until releasing latent heat in the upper atmosphere -> air packet then descends, compresses, and heats due to gravity. This process continues ad infinitum, no greenhouse gases required. The Sun and gravity drive this process, not GHGs, and it would occur in an atmosphere comprised of 100% N2 & O2, as well as in our atmosphere with >99% N2 & O2. Maxwell makes no mention of "radiative forcing" and indeed the erroneous concept of "radiative forcing" of the atmosphere hadn't even been invented by the erroneous Arrhenius at the time Maxwell wrote his theory of heat.

      Delete
    2. You're describing a very wide array of things, one of which actually counters your very point.

      For starters, I had just described an atmosphere where convection was driven by conduction between air and ground. In that atmosphere, the convection *stopped* once the environmental lapse rate reached the adiabatic lapse rate, and further conduction within the air itself drove the atmosphere to isothermal. This is exactly what Maxwell described. *Please* describe how convection operates if NOT for thermal absorptivity. Because purely conduction will lead to an isothermal atmosphere.

      Second, *non-condensible gases do not release latent heat*. If the atmosphere was entirely made out of nitrogen and oxygen, there would be *no latent heat* because those gases do not condense to form liquid in the atmosphere.

      And are you going to respond to the math that I gave you or are you not?

      Delete
    3. "...further conduction within the air itself drove the atmosphere to isothermal. This is exactly what Maxwell described."

      False. Maxwell first described what you are saying:

      "”The second result of our theory relates to the thermal equilibrium of a vertical column. We find that if a vertical column of a gas were left to itself, till by the conduction of heat it had attained a condition of thermal equilibrium, the temperature would be the same throughout [i.e. isothermal"], or, in other words, gravity produces no effect in making the bottom of the column hotter or colder than the top. This result is important in the theory of thermodynamics, for it proves that gravity has no influence in altering the conditions of thermal equilibrium in any substance, whether gaseous or not...."

      But then described why this does NOT apply to the atmosphere:

      ”This result is by no means applicable to the case of our atmosphere. Setting aside the enormous direct effect of the sun’s radiation in disturbing thermal equilibrium, the effect of winds in carrying large masses of air from one height to another tends to produce a distribution of temperature of a quite different kind, the temperature at any height being such that a mass of air, brought from one height to another without gaining or losing heat, would always find itself at the temperature of the surrounding air. In this condition of what Sir William Thomson has called the convective equilibrium of heat, it is not the temperature which is constant, but the quantity ϕ [entropy], which determines the adiabatic curves.
      In the convective equilibrium of temperature, the absolute temperature is proportional to the pressure raised to the power (γ-1)/γ, or 0,29.
      The extreme slowness of the conduction of heat in air, compared with the rapidity with which large masses of air are carried from one height to another by the winds, causes the temperature of the different strata of the atmosphere to depend far more on this condition of convective equilibrium than on true thermal equilibrium.”

      No radiative forcing or greenhouse gases requirement whatsoever to maintain a temperature gradient, only gravity/atmospheric mass/convection/heat capacity.

      Your assumption that the atmosphere would be isothermal in the absence of GHGs is false, thus so are your conclusions regarding the lapse rate.

      Non-condensible gases do not release latent heat, but a dry air parcel still cools as it rises and expands and gains potential energy [from gravity], establishing the dry adiabatic lapse rate.

      I've supplied many links explaining why a non-GHG atmosphere would not be isothermal, you have not said anything convincing otherwise, thus we are at an impasse. Bye

      Delete
  28. recommended:

    http://chiefio.wordpress.com/2014/06/01/le-chatelier-and-his-principle-vs-the-trouble-with-trenberth/

    ReplyDelete
  29. New paper says climate models haven't previously considered radiative-convective equilibrium over land

    http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00654.1?af=R

    ReplyDelete
  30. Kristian says:
    June 16, 2014 at 10:55 am {comment from WUWT}

    First of all. Increased evaporation is a NEGATIVE feedback to surface heating, not a positive feedback to atmospheric heating. Latent heat through evaporation transferred from surface to atmosphere is a (the main) CAUSE of atmospheric heating:
    http://i1172.photobucket.com/albums/r565/Keyell/HeatamprainJRA-25_zpsda38e24a.png

    Secondly, one needs to move away from the completely outdated (19th Century) ‘confined space heating’ idea of CO2 warming. Even ‘climate science’ realised it doesn’t work in the real world already many decades ago. The basic (and necessary) premise behind this idea is that as the IR absorption ability of the lower tropospheric air mass grows stronger with an increase in CO2, there is no buoyant response, no convective change. We all know from everyday experience that this simply can’t and does not happen in the open atmosphere. Energy doesn’t accumulate down low. It is brought up. Automatically. It can happen in a closed glass box in a lab experiment. But that’s not the real earth system. The analogy fails. You can’t reduce the natural temperature gradient away from the solar-heated surface of the earth by simply letting the lower troposphere absorb more surface radiation. In this case, buoyancy wouldn’t simply constitute a partially offsetting negative feedback to CO2 warming. It would completely nullify it, pretty much instantly.

    ‘Climate science’ has of course come up with a more ‘clever’ explanation of how more CO2 in the atmosphere is allegedly supposed to make the surface warmer: The (in)famous ‘raising of the effective radiating level (ERL)’ hypothesis. Which strangely hinges on heating starting from a radiative imbalance aloft and propagating down the lapse rate ladder to end up on the surface. Utterly speculative, counter-logical, un-physical and totally unsupported by real-world evidence, of course. But still what all the warmists fall back on when they realise they can no longer push the ‘heating by back radiation’ nonsense on normal thinking people.

    ReplyDelete
  31. http://tallbloke.wordpress.com/2014/07/13/the-so-called-effective-height-of-emission-vs-the-actual-height-of-emission-which-is-more-informative/comment-page-1/#comment-83365

    ReplyDelete
  32. Misc related comments from elsewhere:

    Richard111 says:
    July 13, 2014 at 7:56 pm
    Here we go again. Aceepting the surface is radiating with a temperature at 14C. Plenty of photons there in the 13 to 17 micron bands. Assuming CO2 can

    absorb that energy just how does it heat the atmosphere aboce 223K, -50C, the peak temperature for the 13 micron band???

    Konrad says:
    July 13, 2014 at 10:14 pm
    The simplest way to dismiss the EEH argument is to rephrase it.

    The claim that adding CO2 raises emission height for the 255K the planet is emitting at and this must raise surface temperature is essentially a claim that

    “adding radiative gases to the atmosphere reduces the atmosphere’s radiative cooling ability”.

    This is clearly illogical.



    pochas says:
    July 24, 2014 at 10:07 am
    The reason that no ‘hot ‘ spot is observed at altitude is that the lapse rate (adiabatic temperature profile) controls temperature throughout the troposphere.

    Warming resulting from an increase in atmospheric moisture will cause the lapse rate to decrease. Surface temperature is actually determined at the effective

    emission height (eeh), which can be considered to be at the Planck temperature -18 C. The question is at what altitude the Plank temperature is reached, and

    this is the eeh. Then the Planck temperature, the lapse rate, and the altitude at eeh together determine the surface temperature.

    This is in contrast to radiative models that consider surface temperatures to result from a radiation balance at the surface. If these models show a surface

    temperature increase from CO2 resulting in increased moisture and a decreased lapse rate, the result will be that temperatures at altitude will move closer to

    surface temperatures, hence the upper tropospheric ‘hot spot.’ However, surface temperatures are actually determined in the mid-troposphere at the altitude

    of the eeh, Then the temperate at eeh (-18 C), the altitude at eeh, and the lapse rate specify the surface temperature, so that a decrease in lapse rate will

    cause the surface temperature to move close to -18 C, a cooling effect. CO2 may actually cause some warming (increase in eeh) but this will be offset by the

    decreased lapse rate as far as surface temperatures are concerned.

    ReplyDelete
  33. Ian W says:
    July 24, 2014 at 11:30 am
    M Courtney says:
    July 24, 2014 at 8:55 am

    Latitude says at July 24, 2014 at 8:30 am

    people might have been right about the absorption bands being saturated after all, or right about negative feedbacks.
    ==============
    As the feedbacks include increased water vapour in the atmosphere – which absorbs at the same wavelength as CO2 – your “or” could well be an “and“.
    Yes, I’ve just argued that increased water vapour is not a positive feedback.

    Water vapour is not a positive feedback because it convects heat upward as latent heat. A volume of humid air is lighter than a volume of dry air, and will

    therefore rise. Heating will increase the convection of the humid air. The water vapour does not warm the atmosphere as the heat is latent until it is released

    higher in the atmosphere on a water state change, condensation or freezing. This release is as IR not as a ‘warming’ collision with Nitrogen or Oxygen.
    Water or ice droplets falling to earth as rain / snow / hail will absorb heat from the air by collision or by absorbing IR and thus cool the volume of air they are

    dropping through and eventually the surface. Eventually evaporating by taking up sufficient latent heat and the hydrological cycle cooling process repeats .

    The bundling in of water vapour as ‘just another GHG’ shows a fundamental misunderstanding of basic physics. Of course it is a negative feedback.


    M Courtney says:
    July 24, 2014 at 11:46 am
    Ian W says at July 24, 2014 at 11:30 am
    The bundling in of water vapour as ‘just another GHG’ shows a fundamental misunderstanding of basic physics. Of course it is a negative feedback.
    I tend to agree as the evidence seems to show that to be so. But this makes us extreme sceptics. Without water vapour amplification the AGW hypothesis is

    unable to be come newsworthy.

    More than that: I propose that water vapour is a feedback that provides the stability in the climate system. That the effect of water vapour adjusts according to

    everything else in order to maintain the temperature of the planet at about the same level.
    CO2 absorption is saturated and if it isn’t then the temperature would rise until the water vapour saturates it.
    And potential water vapour reservoirs are in great excess – we have oceans of it. So the water vapour rise would be rapid. This is where we are, where we

    always are…
    Thus I suggest that CO2 has a negligible effect on our planet.

    ReplyDelete
  34. E.M.Smith says:
    July 27, 2014 at 6:06 am

    More heat at the surface of the topics means more clouds and more rain. Not higher temperatures. (Temperature IS NOT HEAT! Repeat it daily…)

    The tops of clouds dump the heat via condensation of rain / snow / hail as IR that goes into the stratosphere. In the stratosphere, CO2 radiates that heat to space. More CO2 mean more radiated heat from the stratosphere. More surface heat means more water radiating heat. In all cases, it is more heat transport up up and away… There is no ‘trapped’ heat.

    http://wattsupwiththat.com/2014/07/24/climate-models-not-only-significantly-over-predict-observed-warming-in-the-tropical-troposphere-but-they-represent-it-in-a-fundamentally-different-way-than-is-observed/#comment-1695361

    Amen

    ReplyDelete
  35. I am here, climatehoax.ca and arrive at similar conclusions. Perhaps a hundred others have also followed the same logic. Every argument must agree with basic physics. Your remarks are true for every planet with an atmosphere. On the other hand "new" black body expressions are not a law. The surface of the moon gets up to 100 degrees C. There is no green house gas on the moon.

    ReplyDelete
    Replies
    1. Hi, thanks. I wasn't aware of your website but will be checking it from now on.

      Best regards

      Delete
  36. http://www.klimatupplysningen.se/2014/08/12/varmestralning-fran-ovan/#comment-380851

    It's perfectly reasonable that increased carbon dioxide levels in the atmosphere could increase convection, in which case the feedback between carbon dioxide and water in the atmosphere would actually be negative.

    ReplyDelete
  37. Stephen Wilde says:
    September 10, 2014 at 11:13 AM
    “that clear air is being forced to sink by rising air in precipitation systems,”

    That descending clear air then warms adiabatically at the dry adiabatic lapse rate which is faster than the moist adiabatic lapse rate on the earlier ascent.

    Yet no one seems to accept that as a means whereby the surface temperature is caused to rise above the S-B expectation.

    Very strange given that the relevant science is so well known.

    http://www.drroyspencer.com/2014/09/water-vapor-feedback-and-the-global-warming-pause/#comment-132749

    ReplyDelete
  38. CO2 in the lower atmosphere may well lose the energy that CO2 absorbs from IR radiation by convection before there is any chance of radiating. (as “gallopingcamel” says) My, my, if that is so then the general consensus of alarmists (and lukewarmers) would need modification.

    ReplyDelete
  39. Konrad. October 7, 2014 at 1:51 am
    Ferdinand,
    I believe you miss the point. This is not about static atmosphere games with Modtran and Hitran*, this is, as I clearly pointed out, about the theoretical equilibrium temperature of the surface of the planet in absence of atmosphere. The foundation claim of climate science is that this temperature would be 255K. That claim has been repeated too many times to ever be erased. Remember, the two shell model came first, multi layer radiative convective later.

    That 255K figure was obtained by applying the short form of the SB equation to an surface effectively treated as isothermal and with symmetrical emissivity and absorptivity receiving an average of 240w/m2.

    But the oceans are not a near blackbody, they are a greybody or “selective surface”. Effective not apparent IR emissivity is far lower than absorptivity. Further a material that is SW transparent and IR opaque will be heated far more by solar radiation than an SW/IR opaque material with identical specific heat capacity. Depth of SW absorption matter a lot.

    What does it all mean? It means that the equilibrium temperature for the oceans if they could be retained without atmosphere is far higher than the 255K assumption. Far higher than the current 288K. It means that the net effect of our radiative atmosphere over the oceans is cooling of the oceans. And how does the atmosphere in turn cool? Radiative gases.

    Could a non-radiative atmosphere cool our oceans if it had no way to cool itself? No.

    I know you have spent a lot of time studying CO2 in ice cores. The ice core data will have many other uses. But the CO2 = AGW thing could never work, not with deep transparent oceans covering 71% of the planet’s surface. There is a 90K error for 71% of the planet’s surface in the most basic priori of the AGW hypothesis.

    *No there is no joy to be had in the static atmosphere radiative balance calcs. Superimposing a constant rate of tropospheric convective circulation on top was always going to be found out. Yes these gases do warm at low altitude and cool at high altitude. But at low altitude this will just reduce time after dawn to the beginning of air mass breakaway from the SBL and increase radiative subsidence at altitude. Tropospheric convective circulation, the primary energy transport away form the surface, would just speed up for increasing radiative gas concentration.

    http://wattsupwiththat.com/2014/10/06/real-science-debates-are-not-rare/#comment-1756414

    ReplyDelete
  40. D o u g C o t t o n | October 11, 2014 at 5:18 am | Reply
    If any reader does genuinely understand the process described in statements of the Second Law* then they would realise that, for there to be no unbalanaced energy potentials, decreases in gravitational potential energy must be offset by increases in kinetic energy. Computationally, using Cp as specific heat and equating PE loss with KE gain, the latter being the energy to raise mass M by temperature difference dT when there is downward molecular movement through a height difference of dH then we get …

    M.g.dH = M.Cp.dT

    dT/dH = g/Cp

    which is the temperature gradient when thermodynamic equilibrium is attained in non-radiating gases. because of the temperature levelling effect of inter-molecular radiation, so-called GH gases reduce the magnitude of the gravitationally induced temperature gradient, as observed in all significant planetary tropospheres. Thus the thermal profile rotates and the temperature at the base of the troposphere (and in any surface there) is reduced.

    * “Processes in which the entropy of an isolated system would decrease do not occur, or, in every process taking place in an isolated system, the entropy of the system either increases or remains constant


    That version of the 2nd law comes from the textbook An Introduction to Thermodynamics, the Kinetic Theory of Gases, and Statistical Mechanics (2nd edition), by Francis Weston Sears, Addison-Wesley, 1950, 1953, page 111 (Chapter 7, “the Second Law of Thermodynamics”).

    http://judithcurry.com/2014/10/09/my-op-ed-in-the-wall-street-journal-is-now-online/#comment-636939

    ReplyDelete
  41. Another way to put the issue.

    The CO2 hysteria is founded on a false picture of heat flows within the climate system. There are 3 ways that heat (Infra-Red or IR radiation) passes from the surface to space.

    1) A small amount of the radiation leaves directly, because all gases in our air are transparent to IR of 10-14 microns (sometimes called the “atmospheric window.” This pathway moves at the speed of light, so no delay of cooling occurs.

    2) Some radiation is absorbed and re-emitted by IR active gases up to the tropopause. Calculations of the free mean path for CO2 show that energy passes from surface to tropopause in less than 5 milliseconds. This is almost speed of light, so delay is negligible.

    [3)] The bulk gases of the atmosphere, O2 and N2, are warmed by conduction and convection from the surface. They also gain energy by collisions with IR active gases, some of that IR coming from the surface, and some absorbed directly from the sun. Latent heat from water is also added to the bulk gases. O2 and N2 are slow to shed this heat, and indeed must pass it back to IR active gases at the top of the troposphere for radiation into space.

    In a parcel of air each molecule of CO2 is surrounded by 2500 other molecules, mostly O2 and N2. In the lower atmosphere, the air is dense and CO2 molecules energized by IR lose it to surrounding gases, slightly warming the entire parcel. Higher in the atmosphere, the air is thinner, and CO2 molecules can emit IR and lose energy relative to surrounding gases, who replace the energy lost.

    This third pathway has a significant delay of cooling, and is the reason for our mild surface temperature, averaging about 15C. Yes, earth’s atmosphere produces a buildup of heat at the surface. The bulk gases, O2 and N2, trap heat near the surface, while CO2 provides radiative cooling at the top of the atmosphere.

    I would add that this means that convection and conduction are the overwhelming dominate means of heat transfer in the lower atmosphere just like they taught us at university in the early 70s before the madness set in.

    As Peter Morcombe pointed out in conversation with Dr. Brown:

    CO2 has many absorption lines but my personal favorite is the one at 15 microns (wave number 667.7). It takes many microseconds for an excited CO2 molecule to release a photon while the mean time between collisions with nitrogen/oxygen molecules near sea level on Earth is <0.2 nano-seconds. Thus it is that the vast majority of excited CO2 molecules give up their energy to the “bulk of the atmosphere” (as Arrhenius would say) by collision before they have time to radiate a photon.

    The collision time constant is directly proportional to pressure, other things such as temperature being equal. In contrast, CO2 molecules in the stratosphere are much more likely to radiate a photon isotropically so half the radiation will return to the surface or the cloud tops. Will it matter? No it won’t.

    And so it is gravity which causes the atmosphere near the earth to be very, very dense and less dense as one climbs up the mountain (grew up in the Appalachian mountains). As one goes up one notices it gets colder. It is in the upper atmosphere (Stratosphere and above) where the air is very thin that radiation (CO2 being a player there) is the dominate means of moving heat out into space. In the lower atmosphere CO2 radiation plays only a very small role.

    ReplyDelete
    Replies
    1. http://diggingintheclay.wordpress.com/2014/04/27/robinson-and-catling-model-closely-matches-data-for-titans-atmosphere/#comment-6070

      http://wattsupwiththat.com/2014/10/11/a-comparison-of-the-efficacy-of-greenhouse-gas-forcing-and-solar-forcing/#comment-1760322

      Delete
  42. Ian W October 12, 2014 at 3:29 am
    In answer to Thomas October 11, 2014 at 7:47 pm

    Lapse rate is the rate at which the temperature of the atmosphere decreases as one moves up to higher altitudes. Pressure falls, so temperature falls. The wet adiabatic lapse rate is less than the dry rate because when water vapor is cooled it condenses and that process releases heat (the heat of condensation). The latent heat of water vapor is retuned as sensible heat when vapor condenses. This is added temperature is why cumulous clouds roil and “boil” as they build up. I don’t understand why you think the fact that the wet lapse rate is one-half the dry rate would cause the surface to cool.

    The classic ‘wet adiabatic lapse rate’ considers a saturated volume of air and the dry adiabatic lapse rate a zero humidity volume of air. So in that case as soon as the saturated air cools even slightly latent heat will be released as some of the water condenses out. However, the atmosphere is not a black white switch. Most of the air is neither saturated nor dry.

    The volume of air that is immediately above a water surface will be more humid than the air immediately above it. This will have two effects: Firstly the air will have a higher enthalpy, which means that its heat content is significantly higher for the same temperature. This is due to the humidity. Secondly the density of humid air is less than that of dry air therefore even at the same temperature it is lighter this is due to the molecular weight of H2O being lower than that of N2 or O2 the main constituents of the atmosphere and due to Avogadro’s Hypothesis the number of molecules of gas in the volume will be approximately the same.
    The net result is that even if there is no external warming as water molecules evaporate into the air above a water surface, convection will start and remove the higher energy molecules from above the water surface, The air replacing the convecting air will be drier and will take up water molecules then also start to rise. Eventually these rising expanding volumes of humid but not saturated air will stop rising when their buoyancy matches the buoyancy of the ambient air or if they become saturated then the change of state of the water vapor to droplets will take place and you are at the boundary condition that is used for ‘moist adiabatic lapse rate’. However, that level is not necessarily close to the water’s surface and may never be reached (i.e. clouds / water droplets will not form) if the atmosphere is dry. The moist(er) air however will have carried heat away from the water’s surface and thus the water cooled and the heat content of the atmosphere will have increased without any rise in temperature

    Temperature is not a measure of the heat content of air volumes of varying humidity.

    http://wattsupwiththat.com/2014/10/11/a-comparison-of-the-efficacy-of-greenhouse-gas-forcing-and-solar-forcing/#comment-1760315

    ReplyDelete
  43. Richard111 says:
    October 5, 2014 at 8:09 am
    This ‘missing heat’ hiding in the oceans idea is strange. I can understand ‘more energy’ being absorbed in the oceans than is currently accounted for, but I cannot see how it would increase future atmospheric temperatures. It might melt more polar ice but this would cool sea surface temperatures and lead to cooler summers.
    Another idea I find impossible to follow is that ‘greenhouse gases’ absorb IR from the surface and reradiate just half of that energy back to the surface and MAKE IT WARMER ! ! !
    If there is a tutorial on that subject please ensure it includes all 3,800 active lines of IR centred on 15 microns where CO2 in the atmosphere is very active. The total bandwidth is from 13 microns to 17 microns. Please explain how CO2 can absorb ANY radiation over this specific band when it is already warmer than MINUS 50C (223K) which is the PEAK RADIATION TEMPERATURE for 13 microns. When will the current rules on blackbody science be rewritten to account for the amazing phenomena being claimed?

    ReplyDelete
  44. The Great Magical ‘Greenhouse Effect’ Self-Amplifying Loop

    http://okulaer.wordpress.com/2014/10/24/the-great-magical-greenhouse-effect-self-amplifying-loop/

    ReplyDelete
  45. How both the oceans and atmosphere develop an adiabatic lapse rate, with or without the presence of greenhouse gases:

    http://www.klimatupplysningen.se/2014/10/24/min-nya-geovetenskapliga-artikel/

    ReplyDelete
  46. see related comments at WUWT:

    http://wattsupwiththat.com/2014/10/25/changes-in-total-solar-irradiance/#comment-1771445


    Hockey Schtick October 25, 2014 at 7:10 pm
    “In this way, the system reacts to maintain the same temperature despite the changes in forcing. However, I’m happy to listen to alternate explanations and to consider opposing evidence”

    I would suggest the reason is that the thermodynamics of convection, evaporation, adiabatic lapse rate/pressure/atmospheric mass/gravity dominate the troposphere and “short-circuit” most of the radiative forcing, as shown in fig 4 of this paper describing radiative-convective equilibrium in planetary atmospheres:



    http://www.lpl.arizona.edu/~rlorenz/convection.pdf

    also subsequently demonstrated by a paper in Nature by Robinson & Catling to apply to all planets with thick atmospheres in our solar system:

    http://faculty.washington.edu/dcatling/Robinson2014_0.1bar_Tropopause.pdf

    one of several posts describing the Robinson & Catling paper at diggingintheclay.wordpress.com:

    http://diggingintheclay.wordpress.com/2014/04/27/robinson-and-catling-model-closely-matches-data-for-titans-atmosphere/

    i.e. convection dominates over radiative forcing in the troposphere until the atmosphere becomes too thin to sustain convection at P=0.1 bar, i.e. where the tropopause begins and radiative forcing takes over.

    1sky1 October 27, 2014 at 1:19 pm
    Getting wannabe climate scientists to recognize that moist convection outstrips not only radiation, but all other mechanisms combined in transferring energy from surface to the troposphere remains one of the great challenges of blog discussion.

    Reply
    Willis Eschenbach October 27, 2014 at 7:53 pm
    1sky1 October 27, 2014 at 1:19 pm

    Getting wannabe climate scientists to recognize that moist convection outstrips not only radiation, but all other mechanisms combined in transferring energy from surface to the troposphere …

    Citation? The Kiehl/Trenberth budget has it as follows;



    and the CERES data basically agrees, giving the following figures:

    Total of sensible and latent heat loss (moist convection) = 109 W/m2 (K/T says 97 W/m2)
    Upwelling radiation 398 W/m2 (K/T says 396 W/m2)

    In other words, both of them say that radiation is the largest way that the surface loses energy, with moist convection coming in second and sensible heat loss (dry convection) third largest.

    Regards,

    w.

    1sky1 October 28, 2014 at 4:50 pm
    The dominance of moist convection over other mechanisms of heat transfer
    from the surface is well-known among energy-budget experimentalists. In
    all but the driest, coldest environments, measurements usually show that
    the ratio of sensible-to-latent heat transfer (the Bowen ratio) is <1. A
    serviceable introduction to actual surface energy budgets is provided by

    http://www.atmos.washington.edu/~dennis/321/321_Lecture_14.pdf.

    The K&T cartoon tends to obscure these empirical facts by showing large
    oppositely directed radiative fluxes, indicative of radiative EXCHANGE at
    high surface temperature, rather than actual heat TRANSFER in the system.
    In fact, even by K&T's account, the NET radiative transfer is quite small
    (63W/m^2) and appreciably less than that attributed to moist convection.

    Serious physical treatises (e.g., Peixoto and Oort) do not indulge in such
    misleading presentations, which have led many into grossly distorted notions
    of the importance of radiative transfer in affecting surface temperatures.

    ReplyDelete
  47. http://wattsupwiththat.com/2014/10/25/changes-in-total-solar-irradiance/#comment-1771808

    Willis Eschenbach October 26, 2014 at 9:10 am
    Hockey Schtick October 25, 2014 at 7:10 pm

    “In this way, the system reacts to maintain the same temperature despite the changes in forcing. However, I’m happy to listen to alternate explanations and to consider opposing evidence”
    I would suggest the reason is that the thermodynamics of convection, evaporation, adiabatic lapse rate/pressure/atmospheric mass/gravity dominate the troposphere and “short-circuit” most of the radiative forcing, as shown in fig 4 of this paper describing radiative-convective equilibrium in planetary atmospheres:



    Thanks for that, Hockey. The problems with that circuit are that it doesn’t capture the controls on the system, and it doesn’t even consider the tropical albedo variations.

    So rather than the input being some fixed value “i”, in fact the input is

    i = TSI * (1 – albedo)

    But tropical albedo, as I have shown elsewhere, is some function of temperature f(T), and the two are positively correlated.

    So the input “i” is actually

    i = TSI * (1 – f(T))

    Now, other things being equal, the temperature T is in some sense positively correlated with i, the total solar energy hitting the planet.

    T = g(i)

    This leaves us with the overall equation:

    i = TSI * (1 – f( g(i) ))

    The important thing to note about this equation is that providing that

    • temperature (T) and tropical albedo are positively correlated (which they are), and

    • temperature and incoming surface solar are positively correlated (which they are),

    the system will increase in temperature up to a certain point, and the temperature will then stabilize at that point. It is inherently stable, since as temperature goes up, incoming solar goes down. The system will stabilize where the lines cross.

    This stability is actually enhanced by the remainder of the circuit which you show above. This is because (as I’ve also shown elsewhere) the parasitic losses (which are part of Rc) as a percentage of surface input also increase with temperature.

    So your circuit only captures part of the dynamical system. The part it captures is correct … it’s just missing a lot of interconnections.

    Many thanks, there’s much to be learned from such electrical analogues,

    w.

    ReplyDelete