Does the atmosphere cool with altitude due to gravity?

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63 replies · 9K views
Drakkith said:
If the situation was solely about how the kinetic energy of a gas particle behaves as it moves away from a source of gravity, then you would probably be right. But there are many other effects to take into account, such as convection, radiation, etc.

Convection some posters have stated the whole reason that we have lapse rate in our atmosphere is due to adiabatic cooling and heating of convected parcels of air. Their logic is that no convection = no lapse. Are those people wrong?

Radiation makes a lot of sense, but would could completely overwhelm the effects of gravity or just reduce the lapse?
 
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kyle Bacon said:
Convection some posters have stated the whole reason that we have lapse rate in our atmosphere is due to adiabatic cooling and heating of convected parcels of air. Their logic is that no convection = no lapse. Are those people wrong?

No idea. My point was simply that trying to think of this in terms of the kinetic energy of a single gas particle moving against gravity isn't likely to get you anywhere because the situation is far more complicated than that.

kyle Bacon said:
Radiation makes a lot of sense, but would could completely overwhelm the effects of gravity or just reduce the lapse?

I would think that depends on the altitude, density of the gas, type and intensity of the incoming/outgoing radiation, etc. The thermosphere is a good example. It's warmer than the underlying air layer because it absorbs X-ray and UV radiation from the Sun.
 
kyle Bacon said:
Convection some posters have stated the whole reason that we have lapse rate in our atmosphere is due to adiabatic cooling and heating of convected parcels of air.

That's the reason for the adiabatic lapse rate. There would also be a lapse without convection but it would be dominated by radiative heat transfer.
 
kyle Bacon said:
some posters have stated the whole reason that we have lapse rate in our atmosphere is due to adiabatic cooling and heating of convected parcels of air. Their logic is that no convection = no lapse. Are those people wrong?

I'm pretty sure I said that :cool:

And I get where your coming from with the whole "one molecule in a box", but Drakkith is right. A gas isn't just one molecule, it's many and that makes it way more complicated.

Despite earlier successes, this VO is once again insisting that hydrostatic equilibrium must exist because his "Drop Down Cycle" would create energy. Last time a wrong formula was used, so what is it going to be this time?