Why are the top of mountains cold?

Discussion in 'Earth Science' started by John Connellan, Oct 23, 2009.

  1. John Connellan Valued Senior Member

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    Exactly,

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    which is why (especially in the summer) they are warmer than you would think for that altitude (some parts of the tibetan plateau can reach 25-30 C in the summer).

    Again showing that temperature is not directly related to the environmental air pressure.
     
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  3. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    That is not warmer than I would expect for that alititude, in the summer.
     
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I did not respond to this because you are wrong here too, as iceaura explained below! Not much point in my telling you again – you have fixed, often false, views and do not want to learn or change them
     
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  7. John Connellan Valued Senior Member

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    Maybe you are getting me wrong. The reason I think this is because if you had bothered readin all the posts you would have seen I agreed with Iceaura.

    When I said surface in that context, I meant the average surface around the mountain (which is generally considerably lower than the mountain).
    You need to keep on track of the discussion better - remember my opening line:

    How can you not agree with that?
     
  8. John Connellan Valued Senior Member

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    Really? If you take Greece or the south of Spain at a comparable latitude, I would expect the top of a mountain between 3000m and 4000m to be a lot colder than 25 C even in summer (probably about 15-20).
     
  9. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Because it does not RESPOND to the thread's question, with any explanation -It only states again the fact that the temperature in the troposphere decreases with altitude (as you get further form the surface) and falsely implies (or openly asserts) it is the increasing separation from the warm surface which is causing the cooling.

    To explain why this temperature decrease with altitude is true, you need to at least discuss "adibatic cooling." I.e. that when air expands it cools and note that any given mass of air will expand as it moves to higher altitude where the pressuer is less and thus cool.

    Also you have made several false statements, most of which I have corrected.
     
  10. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    Why? There certainly are no such mountains in Greece or Spain for you to base that on.

    Meanwhile, the Atlas Mountains in Morrocco (same latitude and altitude as the Tibetan Plateau) routinely run summer temps around 25 C or higher.

    Likewise the southern Sierra Nevada and southern Rocky mountains.
     
  11. John Connellan Valued Senior Member

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    I don't think the highest point of the Sierra Nevadas reaches more than 20 C even though it is lower than much of the tibetan plateau.
     
  12. John Connellan Valued Senior Member

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    No, you were putting ideas in my mouth I think. Like when you said I was contradicting what iceaura had said - even after I had just agreed with him, which i find amazing.

    I am not talking about "cooling". I am talking about the static state of higher elevations. They are always cold and I have proposed that they are not cold because the temperature of air at a lower pressure is colder than the temperature of air at a higher pressure. Many people I believe are under that assumption.

    My own theory is that these are people who know a little bit of science and may have interpreted the lapse rate wrong - which only applies to air which is expanding.

    And I did mention adiabatic cooling but I said that it's main role is the prevention of heat transfer from the surface by convection.
     
  13. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    You're wrong. I've been to the highest point of the Sierra Nevada in temperatures above 20 C.

    And, by the way, the highest point in the Sierra Nevada is at comparable elevation to the Tibetan Plateau.
     
  14. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    Haven't met any such people. Everyone I know understands that it's changes in pressure that are related to changes in temperature.

    And expansion is exactly what happens to air that moves from regions of high pressure (sea level) to low pressure (mountaintops).
     
  15. John Connellan Valued Senior Member

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    And I'm sure there were times in the midst of summer where temperatures on the plateau approached 30 C.

    Thats not the point. With the same solar radiation incidence (let's say a high one in mid summer), do you really think a mountain with a large single rise would have the same surface air temperature as a location deep in the middle of a plateau with the same elevation all around for miles (given the same altitude)?

    Granted the plateau will always be a bit cooler than sea level for various reasons but you could nearly treat such a location as an isolated system.

    Take an extreme example to prove the point. Let's say you raise half the entire earth's surface 4000m and leave the other half as is. Do you think the surface air temperature at a location inside a large landmass on either side would be very different due to the elevation of the land alone?

    I don't think so anyway.
     
  16. Montec Registered Senior Member

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    Hello all

    The atmospheric phenomenon the OP is discussing is called the Lapse rate.

    Just so we can discuss this thread using a common term.

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  17. John99 Banned Banned

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    i am saying that the surface of the earth is better suited to retaining the heat.

    when the leaves fall they create a substrate in the body of water. this type of substrate has a warming effect on the water. it is an insulator. look at swamps.
     
  18. iceaura Valued Senior Member

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    The lake near me, which has a rock bottom and is much warmer in summer than Crater Lake, is surrounded by pine trees, as is Crater Lake.

    You're getting a bit silly here.
     
  19. John99 Banned Banned

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    i am mentioning one attributing factor. pine trees do not loose their leaves either.
     
  20. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    Sure they do. Just not all at once.

    Growing up, it was always amusing to see flatlanders who'd move to the mountains and think they'll get out of raking duty by planting only evergreen trees on their properties.
     
  21. stereologist Escapee from Dr Moreau Registered Senior Member

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    Way off topic, but tamaracks and bald cypress loose all of their leaves each year.
     
  22. John99 Banned Banned

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    john,i think it is just due to surface area. the rays hit the boundary (earth) and have no place to go but the rys get transformed into heat and the heat lingers close to the surface. relatively close.
     
  23. stereologist Escapee from Dr Moreau Registered Senior Member

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    I've done a lot of big cliffs and in high places like the Sierra. The one thing you notice is how the heat of the sun warms rocks. The hot air will rise along the surface of the face keeping the surface air quite warm even on days where it is quite cold away from the cliff. Rocks are poor heat conductors. The heat absorbed from the sun does not penetrate deep into the rocks. Shadowed portions of the cliff can be cool. The thinner air is drier and does not hold heat well. Notice the sudden drop when clouds hide the sun.
     

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