Would a non radiative atmosphere be isothermal?

  • Thread starter Geoffw
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Main Question or Discussion Point

Many credited physicists have entertained the notion of a non radiative atmosphere being isothermal as a function of height.

But is this a physical reality?

Many physicists accept the macroscopic conclusions of kinetic theory, the gas laws. Statistical mechanics. Experimentally verifiable results from a set of provably reliable assumptions.

So what is wrong with these assumptions and their inevitable conclusions;

"Particles are small and spend most of their time between collisions. They have mass, and therefore feel gravity."

The inclusion of the latter in the frame of the former requires that 'information' about gravity is invested in the very framework of collisional energy transfer.

This is supported by data.

So what, despite supporting data, is wrong with kinetic theory. Why is it not supported by the scientific community?
 

Answers and Replies

  • #2
olivermsun
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What do you mean by "isothermal as a function of height"? Do you mean that the temperature is (horizontally) isothermal at each height?
 
  • #3
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What do you mean by "isothermal as a function of height"? Do you mean that the temperature is (horizontally) isothermal at each height?
No, without the ability to radiate, it is often accepted that the vertical profile would be isothermal. Under those circumstances the atmosphere would be isotropic within its volume.

I find this an unacceptable asssumption in a gravity field.

What do you think?
 
  • #4
jim mcnamara
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@Geoffw
What I think: please supply a source (refereed ) article for your comments. I cannot separate what you think from what you are basing your statements on.
Thanks!
 
  • #5
Baluncore
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The lack of solar radiation heating during the day and cooling by radiation at night, would reduce thermal density changes and therefore vertical movement of the atmosphere.

But what about the Coriolis forces that break the atmosphere into slowly rotating high pressure systems with many smaller counter-rotating low pressure eddies between them? Will that not generate some vertical circulation?
 
  • #6
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No, without the ability to radiate, it is often accepted that the vertical profile would be isothermal. Under those circumstances the atmosphere would be isotropic within its volume.

I find this an unacceptable asssumption in a gravity field.

What do you think?
I think that it is a correct assumption in absence of heat flow, due to properties of Maxwell distribution.
Climbing in a gravity field, the slower molecules fall back down, but the faster molecules slow down. The net result is that at an higher altitude, there are fewer molecules, but their average speed is exactly the same as below.
 
  • #7
berkeman
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Thread closed temporarily for Moderation...
 
  • #8
berkeman
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@Geoffw
What I think: please supply a source (refereed ) article for your comments. I cannot separate what you think from what you are basing your statements on.
Thanks!
Thread will remain closed until @Geoffw can send me a private message with the refereed papers that he is referring to.
 

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