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Post by Ratty on Sept 18, 2017 2:20:58 GMT
Now, to get time to read it. Acidohm and Ratty have added to the conversation with excellent references! .... and at no cost.
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Post by nautonnier on Sept 18, 2017 12:04:13 GMT
Just look at Friday for JoseFujiwara anyone? It does appear that Jose is mid-pirouette TO post the forecast from one of the models again.. Long Island watch this storm.
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Post by blustnmtn on Sept 18, 2017 12:51:18 GMT
đź‘€
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Post by duwayne on Sept 18, 2017 17:47:05 GMT
Missouriboy, we are discussing what happens to the energy as it moves up in atmosphere as you say. Much of this energy is in the form of latent heat which doesn't show up on any thermometer readings. The question is 'What happens when this massive amount of energy is released into the atmosphere?' My belief which I think is universally held by all scientists and engineers is that the heat is passed to the other molecules in the atmosphere. I've been trying get Nautonnier to agree with that so we can go on and discuss what happens next. As a layman on the topic, I have no specific knowledge to contest that view. And perhaps I'm jumping the gun. But ... energy (generic) must be shed to space for the energy balance of the planet to be roughly maintained (assumption). If the energy is bound up as sensible heat in other molecules, are whole molecules shed? Or, is there another transition phase where the molecules (or some portion) are retained while the energy is shed? Missouriboy, I’ve been busy so I haven’t seen or responded to your post until now. I can imagine someone saying “Please explain Einstein’s Equation to me in layman’s language so I can understand and believe it.” That’s pretty much impossible. Fortunately climate science is much easier to understand. But it does help if a layman spends a little time to gain an understanding of just the basics of (1) latent heat and (2) photons. It will greatly enhance their ability to understand the answers to the questions you’ve asked above. So, with that in mind, here’s my layman’s level explanation of latent heat. I hope you'll read through slowly enough to understand what I've written. A water molecule has an almost magical ability to grab an extensive amount heat from its surroundings as it is turning from a liquid into vapor and hide that heat so you don’t see any outward signs that it is present. The water vapor molecule can then “float” up into the atmosphere and condense into water droplets and in so doing it will release its hidden load of heat which results in warming of the surrounding air. That “hidden” heat is called latent heat while it is hidden but it is heat that you can feel both before and after it is latent heat. If you want you can watch this youtube video which describes latent heat in somewhat more scientific terms. www.youtube.com/watch?v=6lAxBTLgYfUHopefully you learned that one water vapor molecule can carry a surprising amount of heat from the ocean to the atmosphere. And then if you read the article below you will see how latent heat plays a key role in thunderstorms and hurricanes by heating the atmosphere. climate.ncsu.edu/edu/k12/.lsheatHopefully, you’ve learned that a lot of molecules using the latent heat trick can contribute significantly to weather events. This will give you a general understanding of what you need to know about latent heat without the confusion of words like kinetics, enthalpy, molecular physics, etc. When I have time, I will post something on photons. Then, Missouriboy, I’ll speak to your questions by building upon the layman level understanding of latent heat and photons.
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Post by acidohm on Sept 18, 2017 19:40:46 GMT
I'm seeing explanations of latent heat as requiring an understanding between kinetic and potential energy.
I get that when a water molecule gets energised enough at boiling point (potential energy??) It vaporizes at a much higher energy level (kinetic energy?)
Doesn't explain however, evaporation at earths surface temps which requires 100°c?
Photon energy from ir concentrated in surface of h20??
Does explain how an h20 molecule reducing excitivity through condensation releases the energy it required to be a gas....
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Post by acidohm on Sept 18, 2017 19:52:51 GMT
Copied off stack exchange...
The real fact is that all of the atmosphere is principally heated by thermal conduction and convection - heating the atmosphere by absorbing infrared radiation is negligible.
Water vapour is accepted to be about 1% of a normal atmosphere. At the Earth's surface the mass of a cubic metre of air is about 1.205 kg. As we go up in the atmosphere pressure decreases and thus so does the mass of air per cubic metre.
At 1% water vapour concentration by volume or about 1.5% by weight there are about 19 grams per cubic metre at sea level - significantly less at higher altitudes. Kiehl & Trenberth claim greenhouse gases produce "backradiation" of 324 Watts / square metre.
A watt is equivalent to a Newton metre per second. A newton is a mass of 1 kilogram accelerated by gravity - 9.8 metres per second.
Hence 324 Watts per square metre is equivalent to 324 Newton metres per second.
324 Newtons is 33 kg subjected to gravity's acceleration.
If anyone can explain to me how a mere 12 grams of water vapour in every cubic metre of normal air at sea level can produce that sort of energy I would feel much enlightened - I simply say it is impossible without furnace like temperatures.
As for Carbon Dioxide at 0.04% by volume which is 0.06% by weight it constitutes approximately 0.732 grams per cubic metre - again significantly less at high altitudes as it is heavier than air.
By similar logic if any one can explain how such an insignificant mass of Carbon Dioxide can produce any detectable quantity of radiation I would feel much enlightened !!
As data from the Moon orbiting satellites a heated surface radiating to space cools at a very slow rate.
True the Moon can become very cold on the night side but that lunar night lasts 354 Earth hours and the surface cools about 290 degrees during that 354 hours - less than a degree per hour.
At that rate the dark side of the Earth would "cool" less than 12 degrees before the Sun rose again.
It is the period of rotation of the Earth that is significant into determining how much the Earth cools.
It is the power of the Solar radiation that determines the maximum daytime temperature.
The atmosphere and oceans reduce the temperature the Solar radiation is capable of causing and there is simple proof in that the Moon's surfaces are heated to over the boiling point of water whilst the Earth never approaches those extremes except when conduction/convection is suppressed or prevented entirely.
Finally do you really believe that although Nitrogen and Oxygen do not significantly absorb Infrared radiation they do not radiate Infrared radiation ?
A well known fact of physics is that everything that has a temperature above absolute zero radiates electromagnetic radiation !
At ambient air temperatures well established physics, Wien's law, predicts that the intensity of the emitted electromagnetic radiation is at a peak well within the Infrared radiation wavelength band.
Almost all of the electromagnetic radiation in the atmosphere is coming from Nitrogen and Oxygen which constitute about 99% of the atmosphere.
The only way Nitrogen and Oxygen would not constitute the vast bulk of this atmospheric radiation is if they were at absolute zero and all the warmth you feel came from 19 grams per cubic metre water vapour and 0.732 grams per cubic metre CO2.
I think that proposition is absurd !
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Post by acidohm on Sept 18, 2017 19:58:33 GMT
Sorry, I'm completely hijacking this thread. If anyone who originated this conversation wishes to, do start a dedicated one??
Meanwhile im mildly obsessing over this, fascinating. This is the only explanation I have found regarding IR absorption I have found that makes any sense....
The absorption of IR radiation is due to vibrations of molecules. When a vibration causes change in charge distribution (or dipole moment to be more specific) the IR radiation is absorbed.
Generally, hetero-polar molecules, like H2OandCO2H2OandCO2, have permanent dipole moment. The external oscillating electric field in this case perturbs the Hamiltonian and causes IR absorption. Hence, they contribute to "Green House effect" by absorbtion of heat.
H2OH2O, which is non-linear molecule, has three fundamental modes of vibrations. Symmetrical Stretching, asymmetrical Stretching and scissoring (bending). CO2CO2, which is linear molecule, has four fundamental modes of vibrations. Symmetrical stretching, asymmetrical stretching and two degenerate scissoring modes, in planes perpendicular. The symmetric stretching mode in CO2CO2 does not produce or absorb any IR, as it does not cause change in dipole moment, but other modes do change charge distribution causing absorption of IR.
Well, the homo-polar molecules, like N2andO2N2andO2, does not have any permanent dipole moment. The external oscillating electric field does not perturb the Hamiltonian for nuclear motion, and does not absorb IR, though it perturbs Hamiltonian for electronic motion. Hence, do not contribute for "Green House effect".
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Post by acidohm on Sept 18, 2017 20:00:11 GMT
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Post by Ratty on Sept 18, 2017 23:05:36 GMT
That taken in your cellar, Blue?
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Post by blustnmtn on Sept 18, 2017 23:58:32 GMT
That taken in your cellar, Blue? While watching Jose and contemplating all the phase changes.
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Post by Ratty on Sept 18, 2017 23:58:43 GMT
Sorry, I'm completely hijacking this thread. If anyone who originated this conversation wishes to, do start a dedicated one?? [ Snip ] Good idea .... would be easier to follow.
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Post by douglavers on Sept 19, 2017 6:14:26 GMT
I once gave a talk on the two most extraordinary liquids.
Water was one of them.
Courtesy the so-called hydrogen bond ...
a] It sticks maniacally to other water molecules ...large surface tension, hard to separate - amazing latent heat of evaporation.
b] Expands when freezes. Otherwise Earth would be an ice-ball. Dominates our weather systems.
c] Amazing solvent - with large polarity. Almost everything dissolves to some extent."Supercritical" water dissolves gold and silica beautifully.
d] Essential to life as we know it - we are just a bunch of colloids .........
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Post by nautonnier on Sept 19, 2017 10:39:28 GMT
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Post by nautonnier on Sept 19, 2017 12:10:27 GMT
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Post by nautonnier on Sept 19, 2017 13:27:25 GMT
Warning issued about Hurricane Maria in Puerto Rico:
"You have to evacuate. Otherwise, you're going to die," said Hector Pesquera, the island's public safety commissioner. "I don't know how to make this any clearer."
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