Does the atmosphere cool with altitude due to gravity?

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Discussion Overview

The discussion revolves around the question of whether the cooling of the atmosphere with altitude is due to gravity. Participants explore various theories, including hydrostatic lapse rates and the implications of the second law of thermodynamics, while also considering anecdotal examples and hypothetical scenarios.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants reference articles claiming that gravity is responsible for the cooling of air with altitude, while others argue that this is in conflict with the second law of thermodynamics.
  • One participant suggests that the atmospheric temperature profile is well-known and questions the validity of the claims made by the authors of the articles.
  • There is a discussion about the effects of night and day on average atmospheric temperature, with some asserting that the difference is not dramatic.
  • Participants raise questions about the implications of hydrostatic gases and whether structures like the Volkshalle could be considered hydrostatic and why it might rain inside such a structure.
  • One participant proposes that the atmosphere is cooler at higher altitudes due to lower pressure and less air, rather than cooling due to gravity itself.
  • There are discussions about mathematical proofs related to hydrostatic lapse rates, with one participant mentioning the use of Excel to analyze formulas for temperature changes with altitude.
  • Another participant questions the scientific consensus on the temperature uniformity of a static gas in an insulated box.
  • The standard climatological explanation for the tropospheric lapse rate is mentioned, emphasizing the role of the Earth's surface in heating the atmosphere.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between gravity and atmospheric cooling, with some supporting the idea that gravity plays a role while others contest this notion. There is no clear consensus on the validity of the claims made by the referenced articles or the implications of hydrostatic gases.

Contextual Notes

The discussion includes various assumptions about atmospheric behavior, the definitions of hydrostatic conditions, and the complexities of temperature variations due to multiple factors, which remain unresolved.

  • #61
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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  • #62
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.
 
  • #63
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.
 
  • #64
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?
 

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