What does temperature in mesosphere mean?

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Discussion Overview

The discussion revolves around the concept of temperature in the mesosphere, particularly how it relates to the kinetic energy of air molecules and the perception of temperature in extremely thin air. Participants explore the implications of temperature measurements in such an environment and the effects of low molecular density on thermal transfer.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that temperature refers to the average kinetic energy of air molecules, which can be high despite the low density of molecules in the mesosphere.
  • Others argue that while the temperature may be high, the thermal transfer to other bodies is minimal due to the sparse population of air molecules, leading to a paradox in how temperature is perceived.
  • A participant questions whether the high temperature should be considered in the context of both electromagnetic radiation and air molecules, suggesting that exposure without protection could be harmful.
  • There are discussions about the meaning of temperature readings in Fahrenheit and Celsius, with some asserting that these readings must have quantitative significance.
  • One participant proposes that the difficulty in measuring temperature accurately in the mesosphere may be due to the time it takes for a gauge or skin to settle, which could be affected by black body radiation cooling.
  • Humorous analogies are made regarding temperature comparisons, indicating a playful engagement with the topic.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between temperature, thermal transfer, and the implications of measuring temperature in the mesosphere. No consensus is reached, and multiple competing interpretations remain present throughout the discussion.

Contextual Notes

The discussion highlights uncertainties regarding the definitions and implications of temperature in low-density environments, as well as the assumptions underlying thermal transfer and measurement techniques.

jostpuur
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I tried to check some atmosphere stuff from here: http://www.srh.noaa.gov/jetstream/atmos/layers.htm

It says

However, despite the high temperature, this layer of the atmosphere would still feel very cold to our skin because of the extremely thin air. The total amount of energy from the very few molecules in this layer is not sufficient enough to heat our skin.

I thought that the temperature is by definition a quantity which always becomes equal between materials which are in physical contact. So if a human body would get cold in the upper mesosphere, doesn't it mean that the air is cold there? Furthermore, if a human body gets cold there, don't temperature gauges get cold too? How are those high temperatures even measured?

update:

I already got one idea. The page explains the reason for high temperatures to be this:

The gases of the thermosphere are increasingly thinner than in the mesosphere. As such, only the higher energy ultraviolet and x-ray radiation from the sun is absorbed. But because of this absorption, the temperature increases with height and can reach as high as 3,600°F (2,000°C) near the top of this layer.

Does this mean that we should consider the system, consisting of both the electromagnetic radiation and the air molecules, to be the system which is in a high temperature? And if a human goes out there and doesn't protect him or herself in a shadow, he or she will get fried?

update 2:

I don't believe that the idea of the first update is the solution to the problem. A better sounding idea is presented in the post #7. Although the frying effect of the sun's radiation is probably notable too.
 
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I think that in this case they're referring the average kinetic energy of the molecules as temperature. If so, the temperature can be quite high, but the thermal transfer to another body would be minimal because of the low population of molecules.
 
Danger said:
I think that in this case they're referring the average kinetic energy of the molecules as temperature.

But they give the temperature in Fahrenheits and in Celsius. Those numbers must have some quantitative meaning.

If so, the temperature can be quite high, but the thermal transfer to another body would be minimal because of the low population of molecules.

This is a paradoxical statement, which IMO doesn't take into account the correct meaning of the terminology. If I understood this point correctly, this message should be said like this: "The average energy of the air molecules is high, but the temperature of the air as whole is low".

update:

I immediately understood another possibility. Did you mean that the temperature of the air is high, but the thermal conductivity is low? But that doesn't make sense really either. If the thermal conductivity of the air is extremely low, then it shouldn't feel cold, right?
 
jostpuur said:
But they give the temperature in Fahrenheits and in Celsius. Those numbers must have some quantitative meaning.

Yes. Temperature means the average kinetic energy of the molecules.

jostpuur said:
This is a paradoxical statement, which IMO doesn't take into account the correct meaning of the terminology. If I understood this point correctly, this message should be said like this: "The average energy of the air molecules is high, but the temperature of the air as whole is low".

Well, I don't think it's paradoxical, and your proposed rewrite doesn't seem on the mark. I think you might be confusing temperature with the thermal transfer. If the average kinetic energy is high, then the temperature is high. But the mesophere's ability to warm objects in contact with it is low because there are so few particles. An object's temperature and it's ability to release heat into objects aren't the same thing.

When you put a room temperature beer in a cooler of ice, you always try to put the can deep in, under the water. Why? Because you have a sense that the cold water can cool down the can faster than the air, even though both are the same temperature within the cooler.
 
Cantab Morgan said:
When you put a room temperature beer in a cooler of ice, you always try to put the can deep in, under the water. Why? Because you have a sense that the cold water can cool down the can faster than the air, even though both are the same temperature within the cooler.

And even more so, I like to use ice water. Essentially the same temperature, but with complete surface contact.
 
Cantab Morgan said:
jostpuur said:
But they give the temperature in Fahrenheits and in Celsius. Those numbers must have some quantitative meaning.
Yes. Temperature means the average kinetic energy of the molecules.

You don't give the average kinetic energy in Fahrenheits or in Celsius. The temperature of a system means the reading that a temperature gauge will give when it is in contact with the system (and is in shadow from outside energy sources).
 
Guys, I understand what you mean. I mentioned something about heat transfer (I used word conductivity) in the update part of my post #3.

I'm thinking more: It could be that the temperature of the air is high, but a direct measurement of it becomes difficult because the time it takes for a reading of a gauge (or a temperature of a human skin) to settle is so large, that the black body radiation of the gauge itself (or of a skin), which will cool the gauge (or skin) down, messes it up.
 
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It's kind of like the question "which is heavier, a pound of feathers or a pound of rocks?"

Which will cook you faster, 1000 degree molten lead or 1000 degree hydrogen at 0.001 psia? :)
 
QuantumPion said:
It's kind of like the question "which is heavier, a pound of feathers or a pound of rocks?
Why the ROCKS of course! Rocks are like... rocks, well heavier man. I mean come on, feathers float!

ZING! Tally of flame posts from people with no sense of humour to follow.
 
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