Can the atmosphere really warm? Atmospheric gas retention.

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donald

Well-known member
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Given recent threads, there seem to be folks here who have crunched through quite some published materials on 'global warming'. So I'd be interested to hear if any of these publications people have read have addressed one conundrum I've never really been satisfied with, in all the discussion on atmospheric warming:

The 'greenhouse effect' is clearly a misnomer because trapping in IR radiation is not how a greenhouse works. A greenhouse works by trapping warmed air. You regulate the temperature of a greenhouse by opening the window at the top to let the hot air out.

The conundrum, then, is that the atmosphere does actually works like this. The atmosphere is not a sealed box that just gets hotter and hotter, instead the atmosphere is free to expand upwards. In fact, you could say the 'greenhouse effect' is a cooling effect by letting the hot air escape because this is a greenhouse's MO!

Consider for a moment how planets retain an atmosphere; gravity matches the thermal excitation of the gases of the atmosphere to retain them, else the atmosphere is lost (loss of mass) or the atmosphere is pulled in closer (increase in pressure), and because the atmosphere can expand without limit, pressure will simply vary so as to meet an equilibrium temperature against which the gravity is balanced.

The logical corollary being is that the equilibrium temperature of a planet is a function of the mass of the atmosphere and the strength of the gravitational field. There may be regional and altitude deviations to that, but overall if the atmosphere gets hotter it will expand and the height of the atmosphere increase until the temperature comes down to a point where diffusion by thermic agitation then balances with the planet's gravity.

Ergo, atmospheric warming can only be localised in characteristic because the atmosphere will expand to compensate for any increases in temperature, tending towards a temperature equilibrium. This will only change if the mass of the atmosphere, or gravity, changes.

Could someone please disabuse me of this notion?
 
donald said:
Given recent threads, there seem to be folks here who have crunched through quite some published materials on 'global warming'. So I'd be interested to hear if any of these publications people have read have addressed one conundrum I've never really been satisfied with, in all the discussion on atmospheric warming:

The 'greenhouse effect' is clearly a misnomer because trapping in IR radiation is not how a greenhouse works. A greenhouse works by trapping warmed air. You regulate the temperature of a greenhouse by opening the window at the top to let the hot air out.
Let's start here. Yes, a greenhouse does contain trapped warm air. But how was the air warmed? It was warmed when energy received from the sun was absorbed by mass inside the greenhouse and re-radiated as longer-wave heat.[1] (It could also have been warmed by a wood stove in the corner, but since that analogy only covers the half of the puzzle you already understand, we'll ignore that.)

The reason gasses in our atmosphere are called 'greenhouse gasses' and support our very, very necessary and natural 'greenhouse effect' is because they also absorb higher-frequency energy from solar radiation and retransmit it as longer-wave heat energy.[2]

Hopefully now you can see this is not a misnomer.

donald said:
The conundrum, then, is that the atmosphere does actually works like this. The atmosphere is not a sealed box that just gets hotter and hotter, instead the atmosphere is free to expand upwards. In fact, you could say the 'greenhouse effect' is a cooling effect by letting the hot air escape because this is a greenhouse's MO!
As you can see, it's not a conundrum after all. But the greenhouse effect is not a cooling process because the net result of a stronger greenhouse effect is retention of more energy - more heat.

Let's make this very clear, though - the greenhouse effect is normal and very much wanted - it's what keeps our climate and planet habitable and on average above freezing. The portion climate science (and environmental science students like me) want to reverse is only the human-caused enhanced effect - the amount of extra heat retention caused when we dredge up old carbon the planet sequestered long ago to bring the greenhouse effect back into balance. This means that folks aren't 'natural-climate-change-deniers' because they understand that our piece of the problem is the enhanced portion beyond the natural cycles.

[1] http://en.wikipedia.org/wiki/Solar_gain
[2] http://en.wikipedia.org/wiki/Greenhouse_gas
[3] http://www.skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect.htm
 
donald said:
Given recent threads, there seem to be folks here who have crunched through quite some published materials on 'global warming'. So I'd be interested to hear if any of these publications people have read have addressed one conundrum I've never really been satisfied with, in all the discussion on atmospheric warming:

The 'greenhouse effect' is clearly a misnomer because trapping in IR radiation is not how a greenhouse works. A greenhouse works by trapping warmed air. You regulate the temperature of a greenhouse by opening the window at the top to let the hot air out.

The conundrum, then, is that the atmosphere does actually works like this. The atmosphere is not a sealed box that just gets hotter and hotter, instead the atmosphere is free to expand upwards. In fact, you could say the 'greenhouse effect' is a cooling effect by letting the hot air escape because this is a greenhouse's MO!
Yes, it is a misnomer. However, that does not mean that CO2 does not cause some warming of the planet.
donald said:
Consider for a moment how planets retain an atmosphere; gravity matches the thermal excitation of the gases of the atmosphere to retain them, else the atmosphere is lost (loss of mass) or the atmosphere is pulled in closer (increase in pressure), and because the atmosphere can expand without limit, pressure will simply vary so as to meet an equilibrium temperature against which the gravity is balanced.
There are many who will dispute that you can get additional warming just from the pressure alone. One thought experiment is what would happen if the atmosphere were entirely composed of nitrogen, which is NOT a greenhouse gas. Dr. Roy Spencer is one who disputes the gravity-only idea vigorously, saying that simulations of a nitrogen atmosphere both with and without CO2 result in different surface temperatures, with no rise with just the nitrogen.

Another common argument is comparing the temperature of Mars and Venus, both having atmospheres almost entirely composed of CO2, although Mars has a thin atmosphere and is cold and Venus has a thick atmosphere and is very hot. This argument does not generally clear anything up since Venus is much closer to the Sun than Mars.

Anyway, the bottom line appears to be that the lapse rate is involved in the warming of the atmosphere, but it may not have any effect in an atmosphere which is entirely transparent to both shortwave and longwave radiation.

The point is that you need some greenhouse gas to make it all work.
donald said:
The logical corollary being is that the equilibrium temperature of a planet is a function of the mass of the atmosphere and the strength of the gravitational field. There may be regional and altitude deviations to that, but overall if the atmosphere gets hotter it will expand and the height of the atmosphere increase until the temperature comes down to a point where diffusion by thermic agitation then balances with the planet's gravity.

Ergo, atmospheric warming can only be localised in characteristic because the atmosphere will expand to compensate for any increases in temperature, tending towards a temperature equilibrium. This will only change if the mass of the atmosphere, or gravity, changes.
This is the belief held by Stephen Wilde, who also has an interesting theory about how the Sun can modulate the Earth's temperature through its influence on the production of ozone and how that can affect global cloud cover.

donald said:
Could someone please disabuse me of this notion?
I find it is very hard to disabuse anyone of any notions regarding the operation of the climate, but perhaps the above will lead you to some interesting back-and-forth on those topics which are found on the internet. Stephen Wilde is certainly an interesting read.

But I will try to disabuse you of one commonly-stated belief related to CO2: That adding CO2 results in positive feedbacks and additional heating from water vapor, which is, by a large margin, the most prominent greenhouse gas in our planet's atmosphere. This belief is at the heart of the major debate and, IMO, it is patently false.

- For the sake of argument, let's just grant that CO2 causes the Earth to warm and each doubling of CO2 concentration would result in a rise of global surface temperatures of 1.4K.
- It is well established that increasing the temperature of the Earth will cause more water, another greenhouse gas, to evaporate from both the oceans and the land into the atmosphere.
- The automatic conclusion that most draw from the above is that this addition of H2O to the atmosphere will lead to further heating since it is also a greenhouse gas: a positive feedback.

To state the obvious, the belief that a temperature increase leads to increased water vapor and hence further increased temperature is an absurd one, since such a system would have run away long ago. What is apparently missed is that increasing water vapor has a vast array of effects on the climate, not the least of which is the increased likelyhood of clouds which increases albedo and cools the Earth.

But what does the data say? Does increased water vapor in the atmosphere heat or cool the atmosphere? Here are a couple of links to help out there: Water vapor, not CO2 controls climate, acts as a negative feedback. Even better is this YouTube video on the topic:
[youtube]http://www.youtube.com/watch?v=Y2K1uHvfaek[/youtube]
With water as a negative feedback on temperature, it seems clear that a doubling of CO2 will cause less than 1.4K of temperature rise in our atmosphere, perhaps significantly less.
 
donald said:
The 'greenhouse effect' is clearly a misnomer because trapping in IR radiation is not how a greenhouse works

Actually, that is exactly how a greenhouse works.


Greenhouse-effect-how-a-greenhouse-works.png
 
RegGuheert said:
But I will try to disabuse you of one commonly-stated belief related to CO2: That adding CO2 results in positive feedbacks and additional heating from water vapor, which is, by a large margin, the most prominent greenhouse gas in our planet's atmosphere. This belief is at the heart of the major debate and, IMO, it is patently false.
Why not inject a little science?

http://www.skepticalscience.com/water-vapor-greenhouse-gas-intermediate.htm" onclick="window.open(this.href);return false;

With water as a negative feedback on temperature, it seems clear that a doubling of CO2 will cause less than 1.4K of temperature rise in our atmosphere, perhaps significantly less.
Perhaps clear to you, less so to climate scientists:

http://thinkprogress.org/climate/2014/03/12/3396341/nasa-study-climate-sensitivity-high/" onclick="window.open(this.href);return false;

http://thinkprogress.org/climate/2014/01/08/3120061/nature-high-climate-sensitivity/" onclick="window.open(this.href);return false;

or, for the more technically minded:

http://www.realclimate.org/index.php/archives/2014/01/a-bit-more-sensitive/#more-16609" onclick="window.open(this.href);return false;

It really isn't hard to find the information if you look.
 
donald said:
Ergo, atmospheric warming can only be localised in characteristic because the atmosphere will expand to compensate for any increases in temperature, tending towards a temperature equilibrium. This will only change if the mass of the atmosphere, or gravity, changes.

Could someone please disabuse me of this notion?

I think earth, through its history, has seen wide temperature changes, which could not be predicted by your hypothesis.

Are you assuming the atmosphere can be described by the ideal gas law, i.e. PV=kT?
 
I appreciate the responses and I'll look at the links.

However, two things to note.

Firstly, a greenhouse just doesn't work in the manner some of you have described above. Whatever the degree of that effect, it is a fantasy to imagine it is a dominant process. It works by trapping air. Trapping re-radiation is a high school science teacher's explanation in the hope of adding in some information about EM radiation. Unfortunately it is false. If you have any published material to the contrary then please link it. Here is just one example of folks who have done the counter experiment:
http://www.principia-scientific.org/publications/Experiment_on_Greenhouse_Effect.pdf" onclick="window.open(this.href);return false;

But I'd like to park that, it wasn't the motivation for mentioning it because I agree that the atmosphere DOESN'T work like a terrestrial greenhouse anyway, and that there are clearly some additional processes going on, as klapauzius logically pointed out.

So, secondly, the thing I really want to get to the bottom of is by how much will the atmosphere expand as it gets hotter. It is an unconstrained mass of gas, except for gravitational constraint, so what really happens if you put thermal energy into a gas like that with a vacuum at the top of it? Clearly it will expand. The question is by how much will the temperature of a gas, so constrained, be mitigated by its expansion into an vacuum? This must've been covered in atmospheric modelling, else how could such modelling be considered 'realistic'.?
 
klapauzius said:
Are you assuming the atmosphere can be described by the ideal gas law, i.e. PV=kT?
That's the starting point for the question. Is there some reason earth's atmosphere would work in some other fashion?

I'm not aware that AGW has also caused changes to the laws of physics, well not yet at least! :D
 
donald said:
Here is just one example of folks who have done the counter experiment:
http://www.principia-scientific.org/publications/Experiment_on_Greenhouse_Effect.pdf" onclick="window.open(this.href);return false;

From that document:

"the warming effect in a real greenhouse is not due to longwave infrared radiation trapped inside the greenhouse, but to the blockage of convective heat transfer with the surroundings"

Actually, the part of the atmosphere in which we all live (the troposphere) does work in a similar way. The "blockage of convective heat transfer with the surroundings" from the troposphere is the stratosphere. Anyone who has seen the flat, anvil-shaped top of a thunderstorm has seen the effect. Heat rises from the surface, hits the stratosphere and stops. Thunderstorms don't just grow and grow until they reach the top of the atmosphere. They stop, very abruptly, quite a ways below that level.

If you want to see the stratosphere on a temperature sounding, look at this plot:

http://weather.rap.ucar.edu/upper/ggw.gif" onclick="window.open(this.href);return false;

Temperature decreases with height from about 27C down to -60C, then stops. Where temperature stops falling is where the stratosphere begins. Almost all the weather we see takes place below that level.
 
Stoaty said:
Why not inject a little science?
I just did. Science is about the data first and foremost. As demonstrated in the links I provided, the overall effect of increased water in our climate system is a decrease in temperature. This is clearly seen with the examples given.
Stoaty said:
http://www.skepticalscience.com/water-vapor-greenhouse-gas-intermediate.htm
This is where they really miss the boat:
Skeptical Science said:
As water vapour is directly related to temperature, it's also a positive feedback - in fact, the largest positive feedback in the climate system (Soden 2005). As temperature rises, evaporation increases and more water vapour accumulates in the atmosphere. As a greenhouse gas, the water absorbs more heat, further warming the air and causing more evaporation. When CO2 is added to the atmosphere, as a greenhouse gas it has a warming effect. This causes more water to evaporate and warm the air to a higher, stabilized level. So the warming from CO2 has an amplified effect.
This is almost precisely what I listed as the premise for the global warming hysteria (see my post above). What you see here is a list of *only* the positive feedback effects of water vapor in our atmosphere rather than a list of *all* feedbacks caused by additional water vapor in our atmosphere. This is known as indoctrination (presenting on one side of an argument).

By leaving out all of the negative feedbacks associated with water vapor in our atmosphere, they give the impression that the OVERALL impact of water in our atmosphere is a positive feedback. But that is simply not true. Adding water vapor to the atmosphere also leads to very strong negative feedbacks which SkepticalScience does not discuss nor do the climate models include in their failed global climate models. First and foremost, as I discussed in the previous post is clouds. Like water vapor and CO2, clouds also have a VERY strong greenhouse effect, but, unlike CO2, they are very reflective of sunlight, which provides a very strong cooling effect during the daytime. This cooling overwhelms the 24-hour greenhouse effect from all the greenhouse gases. Another powerful negative feedback effect is the promotion of biological growth which positively impacts humidity levels which further reduce temperature. Part of this is that trees are now recognized to promote cloud formation. This is why deforestation is so damaging. Not only does it release a lot of CO2, but it also results in dryer and less cloudy conditions which leads to warming, causing more drying, etc.

As pointed out in the video, additional water vapor in the atmosphere is the major reason for the following:
- Dallas is cooler than Phoenix
- Knoxville is cooler than Las Vegas
- Huntsville is cooler than Death Valley
- Bogra is cooler than Riyadh

No, adding water vapor into the atmosphere on Earth does not cause it to heat up. It causes it to cool off.

And you will NEVER figure that out by listing *only* the positive feedbacks of water vapor.
Stoaty said:
With water as a negative feedback on temperature, it seems clear that a doubling of CO2 will cause less than 1.4K of temperature rise in our atmosphere, perhaps significantly less.
Perhaps clear to you, less so to climate scientists:
Yeah, many climate scientists still have a lot to learn. They continue to make very inaccurate predictions which do not come close to matching the real world. Unfortunately, they do not know what they do not know, so some of them are unlikely to learn.
 
The short answers to your questions are:

a) the way to think about it is that infrared radiation IS heat. When you open up the window in a greenhouse you are letting warm air AND infrared radiation out. Two sides of the same coin.

b) A gas may expand if heated but that doesn't mean it cools down. It means it reaches a new volume and pressure that corresponds to the new temperature. Besides, the heat may have apocalyptic effects on human civilization and the environment before any change in volume or pressure are significant.
 
donald said:
klapauzius said:
Are you assuming the atmosphere can be described by the ideal gas law, i.e. PV=kT?
That's the starting point for the question. Is there some reason earth's atmosphere would work in some other fashion?

I'm not aware that AGW has also caused changes to the laws of physics, well not yet at least! :D

Not at all, but you should consider that the ideal gas law is an equilibrium equation.
You fix one variable and the others adapt. Since pressure will always be the same (unless significant amounts of atmosphere disappear or are created), at a set temperature the volume will change. So yes, if it gets warmer, the atmosphere will take up a larger volume.
But keep in mind that in this equation under this assumption you assume the new temperature to be warmer and that the new T is an equilibrium state.

You can take e.g. a balloon and inflate it. Now you have a set volume, pressure and temperature (e.g. @293 K = room temperature). Now hold it over a pot of boiling water. It will expand and as long as you keep it there, maintain the new volume, pressure and temperature.
Same goes for the earth's atmosphere: The temperature increases, the pressure stays the same, hence the new equilibrium has larger volume (proportional to T).
Since T is measured from absolute zero, so at current average atmospheric temperatures ~ 290 K, a change of e.g. 3 K (on the more extreme spectrum of predicted warming) will lead to roughly a 1% volume change...not very dramatic.



What you are looking for is a dynamic description of the earth's atmosphere, which the ideal gas law will not provide.
It does not say anything about how temperature, pressure or volume will change.
 
donald said:
I appreciate the responses and I'll look at the links.

However, two things to note.

Firstly, a greenhouse just doesn't work in the manner some of you have described above. Whatever the degree of that effect, it is a fantasy to imagine it is a dominant process. It works by trapping air. Trapping re-radiation is a high school science teacher's explanation in the hope of adding in some information about EM radiation. Unfortunately it is false. If you have any published material to the contrary then please link it. Here is just one example of folks who have done the counter experiment:
<snip>

But I'd like to park that, it wasn't the motivation for mentioning it because I agree that the atmosphere DOESN'T work like a terrestrial greenhouse anyway, and that there are clearly some additional processes going on, as klapauzius logically pointed out.

So, secondly, the thing I really want to get to the bottom of is by how much will the atmosphere expand as it gets hotter. It is an unconstrained mass of gas, except for gravitational constraint, so what really happens if you put thermal energy into a gas like that with a vacuum at the top of it? Clearly it will expand. The question is by how much will the temperature of a gas, so constrained, be mitigated by its expansion into an vacuum? This must've been covered in atmospheric modelling, else how could such modelling be considered 'realistic'.?
Two points for this stew. The first is that a greenhouse combines a number of functions that work together. Yes, the glazing can act as a thermal barrier and limit energy exchange. But that doesn't address or negate the addition of energy to (or removal from) the system. Both can be happening. This is not some grammar school oversimplification - this is basic physics (the laws of thermodynamics)[1].

Heat transfers via convection, conduction, and radiation. When shorter wavelength energy is absorbed by a rock in the greenhouse and re-radiated as heat, it's random - not coherently focused towards the crack in the glass greenhouse ceiling like a laser beam. Gasses and liquids are poor conductors of energy but they can carry energy around via convection. So while a sealed greenhouse should limit energy transfer via convection, radiation and conduction are still at play on the inside. The warm rock radiates to flower pots - each of which becomes a new point-source of radiation. Some of the energy is radiated to the aluminum structure of the greenhouse - where it's conducted to the outside and radiated from there. The glazing may or may not block some frequencies of radiation but will gain energy via conduction from the aluminum frame and from energy in the circulating air (convection/conduction) and it'll conduct and re-radiate to the outside.

One of the resident physicists will correct me hopefully if necessary, but from an initial scan of your linked experiment it appears to me that the process of confirming that convection is restricted does not mean/demonstrate that radiation or conduction were not active - after all, how did energy get into the boxes to raise the interior temp, and how did it get to the thermometer? I'd like to see the experiment re-run with only one variable change at a time and let's begin with the glazing. I think this is a poorly-conducted experiment with misleading and/or incorrect conclusions.

Other experiments - from those conducted in the 1800s through USAF heat-seeking missile seeker design - show without a doubt that CO2 does absorb energy and re-radiate it as heat. Therefore, anyone that suggests they can 'prove' that CO2 is not a greenhouse gas or does not block some wavelengths of energy or does not re-radiate heat is wrong from the start. And I'm frankly not surprised at the results of the linked 'experiment' since the author is not a professor, not a climate scientist, and has been very active in science-denial and climate-denial circles...[2] I'm calling this 'experiment' garbage and suggesting it was done to deceive rather than duplicate or clarify.

As for the rest, once you recognize the greenhouse effect, thermodynamics, and that we can directly and indirectly measure both the temperature of various layers of the atmosphere and the energy in/energy out for the planet, I think more pieces will fall into place.

Further to Klap's recommendation, these [3] may be useful.

[1] http://www.physicsclassroom.com/class/thermalP/Lesson-1/Methods-of-Heat-Transfer
http://en.wikipedia.org/wiki/Laws_of_thermodynamics
[2] http://citizenschallenge.blogspot.com/2012/10/nasif-s-nahle-google-scholar-and.html
[3] http://farside.ph.utexas.edu/teaching/sm1/lectures/node56.html
http://www.iges.org/straus/CLIM_710/Radiation_Climate.pdf

edit...typos.
 
I'll give donald the benefit of the doubt and assume that he really is trying to rediscover the current scientific understanding, from first principles and not just throwing massive amounts of debris into the waters in order to claim they are "unsettled".

Great. That's also part of science.

But it doesn't serve any purpose to stand on the podium and shout "I AM NOT CONVINCED!" throughout the entire process as you fight each miniscule bit of information. It's beginning to become tiresome.
 
donald said:
Given recent threads, there seem to be folks here who have crunched through quite some published materials on 'global warming'. So I'd be interested to hear if any of these publications people have read have addressed one conundrum I've never really been satisfied with, in all the discussion on atmospheric warming:

The 'greenhouse effect' is clearly a misnomer because trapping in IR radiation is not how a greenhouse works. A greenhouse works by trapping warmed air. You regulate the temperature of a greenhouse by opening the window at the top to let the hot air out.

The conundrum, then, is that the atmosphere does actually works like this. The atmosphere is not a sealed box that just gets hotter and hotter, instead the atmosphere is free to expand upwards. In fact, you could say the 'greenhouse effect' is a cooling effect by letting the hot air escape because this is a greenhouse's MO!

Consider for a moment how planets retain an atmosphere; gravity matches the thermal excitation of the gases of the atmosphere to retain them, else the atmosphere is lost (loss of mass) or the atmosphere is pulled in closer (increase in pressure), and because the atmosphere can expand without limit, pressure will simply vary so as to meet an equilibrium temperature against which the gravity is balanced.

The logical corollary being is that the equilibrium temperature of a planet is a function of the mass of the atmosphere and the strength of the gravitational field. There may be regional and altitude deviations to that, but overall if the atmosphere gets hotter it will expand and the height of the atmosphere increase until the temperature comes down to a point where diffusion by thermic agitation then balances with the planet's gravity.

Ergo, atmospheric warming can only be localised in characteristic because the atmosphere will expand to compensate for any increases in temperature, tending towards a temperature equilibrium. This will only change if the mass of the atmosphere, or gravity, changes.

Could someone please disabuse me of this notion?

Sigh. Get ye to a textbook.

The whole atmosphere doesn't warm, only the bottom. The top of the atmosphere cools.

If the atmosphere was opaque to all wavelength of light including thermal radiation, the surface temperature would not depend on the presence of atmosphere. The atmosphere is not opaque to IR, which you can observe for yourself with a $50 IR thermometer. If the atmosphere was opaque, pointing it up the temperature would read about -270C or -450F.
 
WetEV said:
The whole atmosphere doesn't warm, only the bottom. The top of the atmosphere cools.
OK, that's a new one on me. I'm aware that different levels of the atmosphere may warm and cool variously, but are you saying that there is no net heating and the top always cool if the lower warms? Are you suggesting that the thermal energy content of any given column in the atmosphere remains constant? I'm unclear on your point.

WetEV said:
If the atmosphere was opaque to all wavelength of light including thermal radiation, the surface temperature would not depend on the presence of atmosphere. The atmosphere is not opaque to IR, which you can observe for yourself with a $50 IR thermometer. If the atmosphere was opaque, pointing it up the temperature would read about -270C or -450F.
err... I've no idea what you're saying at all there. If there was no radiation from the earth then the crust would not be cooled and the surface would be molten rock. Clearly there is radiation from the earth's surface that cools, and some of that will be trapped by the atmosphere. No-one disputes that (do they?).
 
donald said:
WetEV said:
The whole atmosphere doesn't warm, only the bottom. The top of the atmosphere cools.
OK, that's a new one on me. I'm aware that different levels of the atmosphere may warm and cool variously, but are you saying that there is no net heating and the top always cool if the lower warms? Are you suggesting that the thermal energy content of any given column in the atmosphere remains constant? I'm unclear on your point.

WetEV said:
If the atmosphere was opaque to all wavelength of light including thermal radiation, the surface temperature would not depend on the presence of atmosphere. The atmosphere is not opaque to IR, which you can observe for yourself with a $50 IR thermometer. If the atmosphere was opaque, pointing it up the temperature would read about -270C or -450F.
err... I've no idea what you're saying at all there. If there was no radiation from the earth then the crust would not be cooled and the surface would be molten rock. Clearly there is radiation from the earth's surface that cools, and some of that will be trapped by the atmosphere. No-one disputes that (do they?).

Oh? You need to start with an atmospheric physics textbook.

Then this wouldn't be new to you.

When you put on a coat, how warm is the outside of the coat? Your skin temperature, or something different? Suppose the coat became better at keeping you warm. What would happen to the temperature of outside of the coat?
 
You're talking in riddles. I can't see how what you are saying relates to the question I am asking.

The very top of the atmosphere is essentially at 0K because gas particles heading upwards will slow, stop, and return back to earth under gravity.

I don't wear a coat in a vacuum. This is why I asked the question. The atmosphere is a different scenario to warming stuff up in a container because the atmosphere isn't a container. It can expand freely.
 
donald said:
The very top of the atmosphere is essentially at 0K because gas particles heading upwards will slow, stop, and return back to earth under gravity.

I don't wear a coat in a vacuum. This is why I asked the question. The atmosphere is a different scenario to warming stuff up in a container because the atmosphere isn't a container. It can expand freely.

Its 2.7 K, because of the cosmic background radiation. Even if we didn't have that, it could not be 0 K because of quantum fluctuations...
Also, because temperature measures only the average energy content, there are actually gas particles that have escape velocity and leave for good...

But of course that is irrelevant to the problem at hand.

So why again is it important that the atmosphere can expand freely?
Keep in mind that expansion does not equal cooling in all circumstances.
 
donald said:
You're talking in riddles. I can't see how what you are saying relates to the question I am asking.

The very top of the atmosphere is essentially at 0K because gas particles heading upwards will slow, stop, and return back to earth under gravity.

I don't wear a coat in a vacuum. This is why I asked the question. The atmosphere is a different scenario to warming stuff up in a container because the atmosphere isn't a container. It can expand freely.

Top of atmosphere doesn't really exist, a tiny fraction of gas particles escape (mostly hydrogen and helium).
Even if there was a top of the atmosphere, it wouldn't be at 0K as particle motion isn't only up and down. North, south, east and west?
Not to mention solar wind heating, which will raise the temperature (aka average velocity) to a lot higher than 0K...

Oh, and K, the thermosphere isn't in thermal equilibrium.

http://en.wikipedia.org/wiki/Thermosphere" onclick="window.open(this.href);return false;
 
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