Layman struggles with Science

[Richard111]

Over at Jennifer Marohasy's blog there is a lively discussion between Nasif Nahle and one neutrino involving formula at close quarters applied with much emissivity and a minimum of absorbtivity. Some of the supporting cast include cementafriend and cohenite. There are many more.

Although it is interesting reading the math is way over my head and is not helping my understanding of how things work, especially the trace GAS carbon dioxide in the atmosphere.

So I thought I would write a comment here describing the level of my confusion and hopefully some kind reader might provide a link or links that will show me the way to enlightenment.

I wish to talk only about the carbon dioxide molecule, CO2, which floats about in the atmosphere, (well mixed) at a ratio of about 1:2,500 (400ppmv) with all the other molecules.

These CO2 molecules are quite lonely little things that spend their time bashing into and being bashed in turn by the much more numerous N2 and O2 molecules plus the occasional Ar molecule and other stuff. While all this bashing is taking place the molecules are exchanging kinetic energy and ramping up and down with regard to their local air temperatures, see my posts 129 and 131 above about the M-B kinetic distribution. At some stage a CO2 molecule will aquire enough energy to fire off a photon of IR energy. But is this purely a function of kinetic energy? Or are the high speed bashes changing the "state" of the molecule as well as the speed?

Have a look at this LINK to get some idea of what the molecule gets up to.

Quote:Because CO2 has more than two atoms, it can vibrate several different ways. These different types of motion occur at different frequencies.
The frequencies of these motions may be calculated based upon the mass of the atoms and the strength of the bonds. Much like the motion of a spring is calculated in a physics class. The animations that are presented here are based upon this type of calculation.

We see that the CO2 molecule can vibrate and/or rotate with asymetric stretch; symetric stretch(not IR active); vertical bend and horizantal bend(degenerate mode with same motion as vertical bend but rotated by 90 degrees) and each state appears to be frequency dependant such that absorbing a frequency specific photon will induce a particular "state".

First question: by absorbing energy and aquiring a new "state" has the kinetic energy of the molecule changed? (speed increase/decrease?).
Second question: if the newly aquired "state" is allowed to decay naturally the molecule will emitt a photon equal to the one it absorbed but how long is the decay time in relation to molecular collisions in the atmosphere? (this time will vary with air density)
Third question: if absorption has only changed the "state" of the molecule how is the increased energy transfered during collisions, is the molecule now in a more "bouncy" state?

I could go on and on but to simplify my thoughts it would appear that GHG molecules absorb more than they radiate at low altitude thus warming the lower air levels. At higher altitude the GHG molecules appear to radiate more than they absorb thus cooling the upper air.

Remember that air density at 7,000 metres is half sea level density so distance travelled between molecular collisions is doubled and it is also possible that the mean speed is also reduced. (lower temperature)

The fact that GH gases warm the lower atmosphere has no effect on the adiabatic lapse rate which is due to earth's gravity. The convective motion UPWARDS increases which is an INCREASE IN COOLING. Check out dry adiabatic lapse rates in deserts, equitorial zones and polar regions. There is a huge temperature range but lapse rates are the same.

I am unable to find any reason whatsoever for the claimed effect of GH gases warming the surface.