Thursday, May 1, 2014

Maxwell established that gravity & atmospheric mass create so-called greenhouse effect

from a comment by climate scientist Pehr Bjornbom at the Stockholm Initiative, a Swedish climate science discussion site that is currently discussing the Hockey Schtick post Why Earth's climate is self-regulating and independent of CO2, Dr. Bjornbom notes that in 1888 the famous physicist Maxwell wrote that gravity establishes the temperature gradient [adiabatic lapse rate] of the atmosphere, which is independent of radiative forcing from greenhouse gases and dependent only upon gravity and heat capacity of the atmosphere [lapse rate = -gravity/heat capacity]. Thus, an atmosphere comprised of only non-greenhouse gases such as nitrogen & oxygen [over 99% of Earth's atmosphere] would create a temperature gradient/adiabatic lapse rate/"greenhouse effect" and not be isothermal as claimed by conventional radiative greenhouse proponents. 

67  Pehr Björnbom  05.01.2014 at. 00:29

Maxwell discussed convective equilibrium in his book Theory of Heat, 1888, pp. 330-331:
”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. For if two vertical columns of different substances stand on the same perfectly conducting horizontal plate, the temperature of the bottom of each column will be the same ; and if each column is in thermal equilibrium of itself, the temperatures at all equal heights must be the same. In fact, if the temperatures of the tops of the two columns were different, we might drive an engine with this difference of temperature, and the refuse heat would pass down the colder column, through the conducting plate, and up the warmer column; and this would go on till all the heat was converted into work, contrary to the second law of thermodynamics. But we know that if one of the columns is gaseous, its temperature is uniform. Hence that of the other must be uniform, whatever its material.”
[the above paragraph from Maxwell is cited by some to claim it applies to the atmosphere, but as Dr. Bjornbom notes Maxwell goes on to say this assumption does not apply to the atmosphere because of convective equilibrium;]
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.”

UPDATE: Maxwell's statement "In the convective equilibrium of temperature, the absolute temperature is proportional to the pressure raised to the power (γ-1)/γ, or 0,29." is referring to γ defined as the "heat capacity ratio" = Cp/Cv [ratio of specific heat capacity at constant pressure to specific heat capacity at constant volume]

also referred to as the Poisson relation based on the ideal gas law & 1st law, which shows remarkable agreement with the gravito-thermal "greenhouse effect" found on all the planets with thick atmospheres [fig 5 & 6 below]:

image
Figure 5. Atmospheric near-surface Thermal Enhancement (NTE) as a function of mean total surface pressure (Ps) for 8 celestial bodies listed in Table 1. See Eq. (7) for the exact mathematical formula. Source: Nikolov & Zeller
image
Figure 6. Temperature/potential temperature ratio as a function of atmospheric pressure according to the Poisson formula based on the Gas Law (Po = 100 kPa.). Note the striking similarity in shape with the curve in Fig. 5.
Derivation from the first law of thermodynamics and ideal gas law [EQ 4] shown here:

13 comments:

  1. I've been getting snipped at WUWT for drawing attention to such matters.

    Looks like I'm in good company :)

    Stephen Wilde

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    1. Yes

      Any additional thoughts on Maxwell's statement "In the convective equilibrium of temperature, the absolute temperature is proportional to the pressure raised to the power (γ-1)/γ, or 0,29."?

      Delete
    2. Makes sense from what I observe in the real world.

      I'm sure the Maxwell position was the consensus science when I was learning basic physics in the 1960s.

      Stephen Wilde

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  2. Maxwell, posh, tisk, tisk, what the heck did he know anyway....

    Shucks, you can hardly get good TV reception with those lousy rabbit ear antennas designed with his silly equations.

    Don't waste your time at WUWT, they are believers, no amount of xplaining will help them. Heck, they even figured out how to make a light bulb brighter by putting another lightbulb next to it. Something that nobody in the whole world of optics (Fresnel, Maxwell, Born, Wolf, Bacon.....) figured out how to do before.

    I'm working on a 100 light bulb array where the output of each light bulb is magnified 100x. I figure if I expand it to 1247 bulbs it will not require any electricity at all to make light. Of course the 1247 number comes from a climate model, so it might be a bit off.

    Cheers, Kevin

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    1. I know, Maxwell's a nobody that only a true denier would listen to, debunked time and again by the Giant of climate alarm, Arrhenius.

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    2. You better not try that experiment, because you see, a dark bulb not receiving any electricity is at ambient room temperature of say 22C, which by Stefan-Boltzmann's Law equates to 430 W/m2 radiative forcing. Therefore, if you put two bulbs next to each other, assuming each back-radiates 50%, both bulbs will warm from the instantaneous radiative forcing 430 + .5*430 = 645 W/m2, and so on in an infinite series until you blow up the planet. DO NOT TRY THIS AT HOME.

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    3. MS, sadly your warning came too late, I stopped at the hardware store and purchased another thousand light bulbs, I frankly could not help myself, got home and hooked them all up, DAMN what I fool I was.....

      There I was, in my garage with 1000 light bulbs, never even finished the last wiring connections, and then BLAMO, the back radiation turned them all ON, shucks the light was so bright I could not even see enough to unscrew those devil light bulbs. Oh what evil Thomas Edison invented.

      Let this be a warning to everybody, never ever allow more than ten light bulbs in the same room at the same time, the back radiation is deadly.

      In fact I STRONGLY suggest that everybody finds some tin foil and wraps all of those dangerous "back radiation sources" in in right away, your families safety depends on it.

      Cheers, Kevin.

      Delete
  3. It was Josef Loschmidt actually. Anyway, that's what my new book is all about "Why it's not carbon dioxide after all" from Amazon, iTunes etc and linked from http://climate-change-theory.com

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  4. You all still follow J.H. and not H.J.

    You follow James Hansen rather than Hans Jelbring, and that’s your problem.

    You think it’s all about radiative heat transfer, when in fact it is mostly about non-radiative heat transfer which obviously is what keeps warm the thin transparent surface layer of Earth’s oceans, the base of the Uranus troposphere, the surface of Venus, the core of our Moon etc etc etc .. throughout the Solar System.

    The greenhouse conjecture adds back radiation to solar radiation and uses the total to “explain” the surface temperature. But of course this is wrong. The original NASA net energy diagram showed only about 165W/m^2 entering the surface, but that gave a far too cold temperature in Stefan-Boltzmann (S-B) calculations, so it had to be nearly trebled with back radiation.

    The problem is, no one should be using S-B and be expecting to get the right answer.

    All that S-B calculations can be used for is the mean temperature of the whole Earth-plus-atmosphere system, and it does give about the right value when you deduct about 30% of incident solar radiation due to reflection, but retain about 20% that is absorbed by the atmosphere itself.

    Now, the big problem with all this is that 70% of the real surface is a thin layer of transparent water, let’s say 1cm deep. If you were to use S-B calculations to determine the temperature of that layer, bear in mind that over 99% of incident solar radiation that is not reflected passes right through it. So you should only use 1% or less of the 165W/m^2 of solar radiation and thus get ridiculously low values. Back radiation doesn’t have a hope, because it does not even penetrate a hair’s width into that first 1cm of water, and if all its energy were converted to kinetic (thermal) energy in that hair’s breadth, it sure would be hot and evaporate rather quickly without warming anything else. The fact that it doesn’t, confirms what I wrote in my paper over two years ago about resonant (or pseudo) scattering.

    So you see, you cannot explain Earth’s surface temperature with radiation calculations, for the simple reason that, like the Venus surface, it receives a significant amount of energy by non-radiative processes as is explained in the Amazon book “Why it’s not carbon dioxide after all” by yours truly.

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  5. The "experiment" which confirms the gravito-thermal effect is the Ranque-Hilsch vortex tube. Look it up in Wikipedia and then open the "talk" page and see my explanation under "How it works." Better still read my book (from $5.95 on Amazon - also iTunes) "Why It's Not Carbon Dioxide After All."

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  6. Maxwell was actually wrong in assuming that the temperature gradient would not appear in a sealed cylinder. Roderich Graeff has carried out over 850 experiments and virtually all showed a non-zero temperature gradient cooler at the top.

    This all stems from the process described in statements of the Second Law of Thermodynamics. The state of thermodynamic equilibrium has maximum attainable entropy. As both potential and kinetic energy affect entropy, that state must be isentropic, meaning that it has no unbalanced energy potentials. Hence the mean sum (KE + PE) must be homogeneous, and hence there must be a temperature gradient because there is a PE gradient.

    But what is critical is the corollary pertaining to what I called "heat creep" in the book. You cannot explain any observed planetary temperatures in the Solar System unless you recognise that this process occurs.

    This is the new 21st century paradigm which totally and finally demolishes the radiative greenhouse conjecture. Look inside my book here ...
    http://www.amazon.com/dp/1478729228#reader_1478729228

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  7. Hi, I'm not averse to this approach, but then why are the ocean deeps colder than the surface? They should be warmer no? Independent of vulcanism etc.

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    1. The Sun heats the bottom of the atmosphere & top of the oceans. Heat rises in both & convection establishes the temperature gradients

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