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You're aiming too high
...
Go low, and then a little lower
originally posted by: TheRedneck
a reply to: Greven
And on the opposite side of the Earth at the time? What then?
A little thing called "thermal mass."
I'm not sure what you're getting at here. Your calculations appear sound on the surface, but I fail to see where they disprove conduction/convection atmospheric heating. I have mentioned the high specific heat and heat of fusion of water many times to explain why the predictions of massive sea level rise are not realistic.
There is conduction/convection heating of the atmosphere, but there is also radiative emission occurring; the two are not mutually exclusive. There is some ice sheet melt occurring, and there is some not occurring. There is some absorption/re-emission of infrared emissions. None of that is in question; only how much is in question.
Assuming for the moment your 1000 W/m^2 figure (I was thinking it was closer to 1500, but that's not important right now), how many watts of energy are absorbed and how many are reflected (albedo)? What change in temperature will the absorbed energy create (specific heat)? What rate of heat transfer to the atmosphere will occur from this (conduction)? How much heat will escape as blackbody radiation? What will be the frequency spectra of this radiation? How much of this radiation will be absorbed/re-emitted by atmospheric gases? How much atmospheric heat will be dissipated by wind (convection)?
The answer is, we don't know. We have estimates being tested in computer models, but it is simply not possible to exactly calculate those variables. The albedo, for instance, can change drastically from one area to the next, even within a span of a few feet. The local thermal mass can shift drastically simply based on when it rained last. Blackbody radiation calculations are theoretical, meaning they are based on the perfect blackbody, which does not exist in reality.
Now, we can get some pretty close approximations on several of these variables, but there is also the question of what effect local variations have on the overall calculations. Wind, for instance, is primarily caused by uneven surface heating... wind contributes to convection heat exchange... so how do we calculate that? We really can't. It wasn't supposed to rain yesterday, but it did. We calculated the effects of the air masses moving through and made a guess, and the guess was wrong. If I had lived ten miles away, the guess would have been right. It was right for most people in this general area.
Do you see the problems with your theory?
Which theory? That the surface of the earth is warmed by solar radiation and heats the atmosphere through conduction/convection? That's not my theory; it's a proven fact.
It almost sounds like you are trying to prove that the fact that water evaporates is proof that carbon dioxide is heating the atmosphere because there's not enough solar radiation to do so. If so, that is ridiculous. Carbon dioxide does not produce heat; under the right circumstances, it can affect the direction of radiative heat energy through spectroscopic absorption/re-emission. It cannot produce heat.
TheRedneck
It is insufficient when the amount of energy striking the surface is barely enough to melt ice. This is part of the reason why it takes so long for the sea ice at the poles to melt despite sunlight all day long during their respective summers (another big part is the low angle).
I would hope the calculations are without too much error, but they're not about convection or conduction. You and the OP both seemed to have this idea that the Sun was enough to explain water vapor in the atmosphere. This is, by way of those calculations, clearly not so.
What screws around with the convection/conduction idea is the fact that the atmosphere does not get increasingly cooler with altitude as a rule - this only happens in some parts of the atmosphere, inverts in other parts of the atmosphere, and basically doesn't change in the pauses.
Water vapor doesn't produce heat either (there is latent heat from condensation, but that heat came from the evaporation in the first place). What water vapor and carbon dioxide do, as greenhouse gases, is alter the movement of radiation. Instead of all that energy (remember, it's nearly 80% of the surface energy loss) radiating outwards and keeping the Earth at a chilly 255°K, it instead runs into a veritable minefield of molecules. This is primarily why the Earth is consistently warmer at the surface, and gets progressively cooler as altitude increases until it reaches the tropopause.
As you should clearly see the math just doesn't work for the Sun alone, how did water vapor come to exist in the atmosphere in quantities sufficient to induce a greenhouse effect?
originally posted by: TheRedneck
a reply to: Greven
I'm still not sure what you're getting at. You seem to be comparing instantaneous energy rates with temperature (which is a measure of energy contained in the mass). That makes no sense mathematically/physically.
Where, then, does this extra energy come from, if not the sun? Other energy sources, such as radioactive decay of trace elements in the planet or gravitational flexing, are negligible and inconsequential. Water vapor in the atmosphere exists (to a degree that has us in a flash flood warning at the moment), regardless of how many times someone calculates something that says differently.
When the math directly contradicts reality, the math is incorrect, either by virtue of a lack of understanding of mathematical applicablity, or by a lack of understanding of physical processes involved and modeled.
As for conduction/convection, yes, it occurs at a very slow rate due to the thermal resistance of air. Where did I dispute that air has a very high 'R' value? Trapped air is one of the best heat insulators we know of, and is the active insulating element in most insulation materials.
Thermal resistance does not prohibit conduction, however. High insulation values equate to the rate of heat transfer and only cover one part of the equation. The other part is the temperature differential. Trapped air will reduce that temperature differential quickly, allowing the thermal resistance to dominate the equation. Open air, however, convects the heat away from the source movement caused by density variations, keeping the temperature differential higher for a longer period. Thus, I included convection in the description.
No one is discounting radiative heat dissipation, which would occur in higher elevations than conduction/convection. Just because one may be responsible for the actions close to the surface, it does not discount the possibility that another is responsible for higher-elevation phenomena.
This is not an 'either-or' situation. There is more than one dynamic happening at the same time. It appears you want to treat it like a contest - "my action does everything; your action does nothing." Sorry, but science doesn't work that way. You're thinking of a sporting event. Math doesn't work well on those.
You just contradicted yourself in two adjacent paragraphs.
The first paragraph quoted above is correct: no gas creates heat energy, and all a 'greenhouse gas' does is slow radiative emissions through absorption/re-emission. But that then means that they cannot contribute to the amount of energy received, which means the only energy source is... the sun!
I know those equations are fun to play with, especially the one with the 4th-order term... wow, that is awesome! I thought so too the first time I saw it. However, proper use of mathematics require an understanding of the physical processes they describe and the applicability of the equations to those processes.
Physics is the subject under discussion. Mathematics is the language of physics.
If we were discussing English Lit, writing a book of nonsense doesn't 'prove' anything, even if it is written in English.
TheRedneck
originally posted by: TheRedneck
a reply to: Greven
So, what warmed the Earth such that water vapor can exist?
That's simple...
Solar radiation warms the surface of the planet. Heat is transferred to the lower atmosphere by conduction/convection.
Radiation is not the only way heat can travel. The very fact that the lower levels of the atmosphere are so much warmer than the upper layers indicates conduction/convection is the primary method of heat dissipation at the surface... not radiation.
TheRedneck
originally posted by: Greven
So, what warmed the Earth such that water vapor can exist?
What do you make of the perpetual existence of water vapor in the atmosphere, if you believe CO2 isn't particularly significant?