"Temperature" of the thermosphere

If one were to place an ordinary mercury thermometer somewhere in the thermosphere (I dont think that has ever been done before!), what would it read (in degrees centigrade)?

 

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The temperature of the thermosphere ranges from -100 C at the mesopause to over 1000 C at the thermopause.

Nobody has used an ordinary mercury thermometer to measure these temperatures because an ordinary mercury thermometer is the wrong tool for making such measurements. Such a thermometer would register well over 100 C if exposed to sunlight, and well below zero if shaded. The reason is that for a macroscopic object such as an ordinary mercury thermometer or a spacecraft, radiative heating and cooling processes will dominate (by orders of magnitude) over convective heat transfer with the thin thermosphere.

 

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Can you explain in a bit more detail how the location would affect the temperature? Do you mean -80 at the bottom and +60 at the top of the thermosphere?

Wouldn't time of day also be important? Also how did you come up with those figures out of interest?

 

I've actually read from 500-2000C but again I am not really interested in the temperature of the thermospheric atmospere itself, rather the temperature you would feel if you were up there.

What would the well below zero be exactly? I keep seeing this on web pages. Is there a way of working out what the minimum night temp would be without having to actually use a thermometer?!

 

I suspect some cracking of pots here, John, given the nonsense your are spouting over in the Earth sciences forum.

This is the topic of multiple books. Here's one: http://www.aero.org/publications/gilmore/front.html

 

I disagree with your use of terms. Typically when people refer to the temperature of an atmospheric layer, they're talking about the ability of that lays ability to transfer energy into an object through thermal diffusion. While it's true that the relatively unshielded particulates that make up the atmosphere have a more direct interaction with the solar radiation, their density and pressure is extremely low - I imagine 1kpa at most and far less. I don't know the pressure profile of post-Stratosphere off hand.

A fully shielded black box with implied minimal rayleigh scattering should experience temperature far below 0. Most atmospheric measurements - and atmospheric averages - are given under no sunlight (Ironically with the exception of the surface boundary layer in the Troposphere). Certain aerosols blown up from desert regions in the stratosphere can reach enormously high temperatures that are unrepresentative of their sphere - their presence is typically sub 10 ppm and more importantly their cross-sectional area is very tiny.


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Oh, this thread belongs in Earth sciences.

 

What nonsense have I said in the earths science forum? 500-2000 degrees Celsius is what I have read. Why are you getting so upset about this and why are you taking it out on me?

Why do you register with these forums if you don't want to talk science? Why is there so much abuse abuse on these forums?

I suspect most of the abuse comes from people are being defensive because they realize don't know enough

 

And would you care to estimate how far below zero?

Interesting. I would have assumed there is quite a variation between day and night is there?

 

I would not.

I mean to say that radiosondes intentionally shield their thermometers from direct sunlight - or might not even need to, they might have upgraded to thermistors by now (which are shielded). A thermistor wouldn't show significant temperatures in the thermosphere shielded. Unshielded it would probably be destroyed by radiation.

Diurnal temperature changes are significant, they're estimated locally from upper air launches at 12UTC and 0UTC worldwide.

 

Can they send radiosondes to the thermosphere?! :bugeye:

 

That's what I need to know

 

Meteorologists, physicists, atmospheric scientists and astronomers are all going to give you a different answer which depends on their method and technique of measurement.

 

Well if we put a mercury thermometer in the middle of the thermosphere at night, there is only one reading that we can all agree on. Thats the technique but I need some kind of estimate of what the thermomenter would read!

 

Disagree all you want. You're wrong. Typically when scientists refer to the temperature of an atmospheric layer they are talking about temperature as defined by kinetic theory.

 

What form of science is this ominous scientist working in? Atmospheric Sciences typically don't deal with kinetic theory or utilize Brownian motion to determine daily atmospheric temperatures. As far as I know the two types of atmospheric sciences consistently deal with temperature in these terms are; atmospheric chemists, and someone working with cloud physics or optics. Meteorologists and climatologists use determine sensible heats to determine instabilities. Albeit, they don't typically work past the tropopause. I guess you're right if you don't consider macro-scale atmospheric dynamics a science...

 

Does the earth's atmosphere evaporate? If it does, it will only be the highest energy particles that make it out, and so the particles in the outermost layer should have the most kinetic energy .

 

https://raids.nrl.navy.mil/hardware.html
http://www.aad.gov.au/default.asp?casid=2139

O rly?

Could you then please explain why think so much work has been done in the last fifty years in the field of remote sensing?

 

So that one day we may have a more comprehensive knowledge of aerosol distributions and energy budgets - terrestrial and atmospheric.

Currently many generalized models take into account aerosols for extended general forecasts on the scale of decades and longer. For the most part the precision needed doesn't exist for them to be of any great use. I've seen them used to forecast dust storm warnings. However; the very limited aerosol data has been recorded over relatively homogeneous climatological events and hasn't yet been proven useful as much more than a result of factors - rather than a forcing factor.
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To be fair about it, I've read studies that related energy budgets to aerosol counts resulting in decreased sea surface temperatures which directly relate to reduced rainfall over the Sub Saharan Sahel. I don't deny there's applicable use for viewing temperature conceptually as kinetic energies, or that the future will probably be based entirely on them. Currently, that's not the case.

 

So, we have spent god-knows how many billions of dollars on remote sensing satellites during the last fifty years just so that "one day we may have more comprehensive knowledge"?

Why don't you stop while you are only starting to make a fool of yourself?