Looking down you will notice that there is practically no absorption at 100 m, and the CO2 and water bands grow in with altitude. This is because the layers near the surface are practically at the same temperature as the surface so the atmosphere appears transparent with equal amounts of absorption and emission. As one goes higher there is more absorption than emission, so the window closes.

For those who wish, the application to see these things is at

http://geosci.uchicago.edu/~archer/cgimodels/radiation.html

It doesn’t get blocked it gets diverted some gets used before being radiated off to space e.g. something had to power my sailboat.

What we see in the upward looking chart is that the atmosphere radiates very well in bands where there are polyatomic atmospheric species with resonant vibration modes not so well where there aren’t. Without them the atmosphere will take quite a bit longer to cool but then without them the atmosphere would probably not warm as fast or as much.

Without polyatomic my sailboat would probably never have worked but then we would be here either and would it never have been built in the first place.

I know you “see” the same thing at 70 km looking down but is it really the same think you are looking at. At 20 km you are looking at and seeing in the window the surface radiation barely modified and that would be the similar at 70km but wrt 15micron band we are looking at the radiation from CO2 at different heights to a depth of a few metres because of the atmospheric opacity in that band. Strangely enough the temperature at around 70km is very similar to the temperature at 20 km, so perhaps we aren’t really seeing the same thing at all. We can’t even see the thermal radiation due to the higher temperature at the stratopause in the 15 m icron band.

Now that rather boring trivially obvious lot is not really relevant. Looking down from 20 km you see the surface radiation in the window which is at the BB equivalent of 268K the upward one shows the same temperature driven radiation from the CO2 absorption band meaning the temperatures are the same. That the downward looking radiation at 20 km for the CO2 band is ~220K hardly surprising as that is about the temperature of the tropopause where the kinetic energy has been converted to potential energy.

Perhaps not to you but I didn’t expect that it would.

for a constant entropy

dQ = dU – dW

dQ is the energy input dU is the change in internal energy dW is the energy required to do work (for example convection) nothing is lost it can’t go anywhere except out. The radiation form the atmosphere is proportional to the 4th power of temperature or if you prefer the 4th power of it’s average kinetic energy now the higher you go the more of this kinetic energy has been converted to potential energy which does not contribute to the radiation this is the “leak” Rabbett is talking about but as you can see it’s not a leak.

As the parcel of air sinks it regains the kinetic energy from potential energy.

That doesn’t explain anything that you are talking about.

“Each layer is in local thermal equilibrium, which is actually an approximation, with the one above and below and that includes the solid surface with the skin layer.”

Makes me think you have no idea what you are talking about, you seem to be at some stage of understanding that has not reached to the level of Calculus yet.

Each layer is in local thermal equilibrium, which is actually an approximation, with the one above and below and that includes the solid surface with the skin layer.

You can even see it in a MODTRAN simulation downward looking at 100m where the BB radiation in the window as at the surface temperature and that in the CO2 absorption band it’s due to emission from CO2 at the same temperature.

http://i229.photobucket.com/albums/ee272/JanPompe/rad29193535.gif

Law of conservation of energy is well established.