As you said, the energy from infrared radiation absorbed by GHGs in the lower atmosphere will quickly be passed on to other molecules in the lower atmosphere by processes such as conduction because the mean free path is so low in the lower atmosphere.
No I don recall saying that. I think I said that energy absorbed via conduction at the surface by ALL molecules can be passed onto CO2 thus heating them up. Just like CO2 can collide with the surface and absorb energy. Collisions swamps and will inhibit the ability of CO2 to absorb thermal radiation direct from the surface.
Collisions between all atmospheric molecules provide translational, rotational, and, importantly from your perspective, vibrational energy to the CO2 molecule. While CO2 may indeed absorb some radiation directly from the surface via the wings of its absorption bands during the daytime. The majority of the Earth's thermal emission is not within the ideal absorption range of CO2 which is around 15um it is indeed at the ideal range around the top of the troposphere. Perfect for radiating out to space where the air is less dense and the effect of collisions is greatly reduced. Even for the wavelengths that fall within CO2's absorption range.
Collisions between air molecules (including CO2) dominate energy transfer at the surface, making conduction and collisional processes far more significant than radiative absorption in this context.
So from my readings i am not convinced of the settled science. i never see real math being used. In fact all I read is that it is "a lot" "and we know" or "it is settled" and so on. Never any math. Metrology already explains our surface temperature via the lapse rates. pretty simple stuff.
FYI - I download a sheetload of RAOB data all the time trying to get my head around atmospheric science and behaviour of our atmosphere. It actually is quite fascinating on how the the Ideal gas law is set up to deal with different molecules. Sure i am no scientist. I am an electrician who was trained in understanding energy transfer between atoms and molecules in copper cables or understanding light emissions from molecules in H.I.D lighting when electrons radiatively de-excite in energy levels. YES THAT is what we learnt as electrician's back in my day. That does not happen anymore.
So from my take on the situation it is like latent heat is being confused as Back IR.
Clearly there is not enough room for both facets of science. Either the moist adiabatic lapse rate explains our temperature or a version of Back IR heating does. It cannot be both
Why? Because that infrared energy would otherwise have left the Earth at the speed of light, but now the energy has been absorbed by the lower atmosphere, and is leaving the lower atmosphere via the much, much slower mechanical processes of conduction and convection. Yes but that is not Back radiation is it. In fact the absorption (conduction) of the very hot surface reduces the amount of high frequency thermal radiation from the surface via conduction and the subsequent dilution of that energy the higher in altitude we go via "as you put it the "much slower mechanical process of conduction and convection" results in the point in the atmosphere where thermal emissions to space become apparent.
Energy leaving slower means a warmer Earth. Yes, but that is not back radiation, is it? In fact, the absorption of heat at the surface (via conduction to the air) ends up reducing the higher-frequency thermal emissions from the surface than that of the upper troposphere.
As this energy is transferred through conduction and convection it is diluted via adiabatic expansion the higher in altitude we go. More energy is redistributed through as you point out the mechanical processes like conduction and convection (FYI-WHICH IS NOT SLOWER in the frequency of the events compared to the actual emission frequency).
Eventually, at higher altitudes, the troposphere becomes thin enough for thermal emissions to space to become apparent.
that is my take.
- Forums
- Political Debate
- NO such thing as Climate Change?
NO such thing as Climate Change?, page-1214
-
- There are more pages in this discussion • 1,595 more messages in this thread...
You’re viewing a single post only. To view the entire thread just sign in or Join Now (FREE)