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What does temperature in mesosphere mean?

  1. Mar 24, 2009 #1
    I tried to check some atmosphere stuff from here: http://www.srh.noaa.gov/jetstream/atmos/layers.htm

    It says

    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:

    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.
     
    Last edited: Mar 24, 2009
  2. jcsd
  3. Mar 24, 2009 #2

    Danger

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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.
     
  4. Mar 24, 2009 #3
    But they give the temperature in Fahrenheits and in Celsius. Those numbers must have some quantitative meaning.

    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?
     
  5. Mar 24, 2009 #4
    Yes. Temperature means the average kinetic energy of the molecules.

    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.
     
  6. Mar 24, 2009 #5

    Danger

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    And even more so, I like to use ice water. Essentially the same temperature, but with complete surface contact.
     
  7. Mar 24, 2009 #6
    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).
     
  8. Mar 24, 2009 #7
    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.
     
    Last edited: Mar 24, 2009
  9. Mar 25, 2009 #8

    QuantumPion

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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? :)
     
  10. Mar 25, 2009 #9

    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.
     
    Last edited: Mar 25, 2009
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