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Post by kiwistonewall on Mar 28, 2009 1:43:51 GMT
Its (Mesosphere) colder in summer over the Arctic. www.uaf.edu/news/a_news/20070817155816.html"Collins said. Solar radiation heats the lower atmosphere, causing a rising cell of air over the summer pole, he said. “As the air rises it cools and that beats out the radiative heating.” Those cold temperatures allow the ice clouds to form in the mesopause. The clouds could serve as an indicator of climate change because an increase in carbon dioxide, which causes heating in the lower atmosphere, causes cooling in the upper atmosphere." Ignoring the required "climate change" mantra every scientist now has to use, we see: 1. We have warm air rising by convection. 2. We have water vapour condensing to ice - this releases latent heat! 3. In spite if this heat, the mesosphere is cooler since the ice crystals reflect sunlight. I'm ignoring the nonsense (thermodynamically speaking about CO2 warming the lower atms. and cooling the upper. All radiative absorption and emission is equally likely at any temperature. Wiki: "The mesosphere (from the Greek words mesos = middle and sphaira = ball) is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere. The mesosphere is located from about 50 km to 80-90 km altitude above the Earth's surface. Within this layer, temperature decreases with increasing altitude due to decreasing solar heating and increasing cooling by CO2 radiative emission. " The cooling clouds may be induced by increased cosmic radiation reaching earth (Solar cycle effect) "
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Post by steve on Mar 28, 2009 11:21:12 GMT
Interesting story. I didn't quite follow the reasoning for why the clouds form more in summer, but the general idea of the cooling mesopause fits with the CO2 theory.
I'm not aware that there is any claim that cosmic rays can cause noctilucent clouds. The only claim I'm aware of is a vague correlation between low-level cloud at certain latitudes. And I sincerely doubt that cloud chamber conditions exist in the mesosphere.
Kiwistonewall, you misquoted what he said about CO2 and lower vs upper atmosphere. It is not that CO2 is "warming the lower atmosphere" it is that increased CO2 is "causing" the lower atmosphere to get warmer.
It's an important nuance that he has deliberately made, I think.
An analogy is that a hat doesn't warm your head (because obviously it's just a bit of material, and it is colder than your head). But putting on a hat causes your head to become warmer.
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Post by magellan on Mar 28, 2009 20:06:02 GMT
Interesting story. I didn't quite follow the reasoning for why the clouds form more in summer, but the general idea of the cooling mesopause fits with the CO2 theory. I'm not aware that there is any claim that cosmic rays can cause noctilucent clouds. The only claim I'm aware of is a vague correlation between low-level cloud at certain latitudes. And I sincerely doubt that cloud chamber conditions exist in the mesosphere. Kiwistonewall, you misquoted what he said about CO2 and lower vs upper atmosphere. It is not that CO2 is "warming the lower atmosphere" it is that increased CO2 is "causing" the lower atmosphere to get warmer. It's an important nuance that he has deliberately made, I think. An analogy is that a hat doesn't warm your head (because obviously it's just a bit of material, and it is colder than your head). But putting on a hat causes your head to become warmer. An analogy is that a hat doesn't warm your head (because obviously it's just a bit of material, and it is colder than your head). But putting on a hat causes your head to become warmer. Does the hat have a little heater inside it? Why not just place reflective mirrors and trap the IR reflecting off the head? Better still, use clear cellophane wrap, fill with .08% CO2 and see if the head warms.
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Post by kiwistonewall on Mar 28, 2009 21:01:05 GMT
If you have hypothermia, you are (if you get rescued) wrapped in a metallic reflective foil - not a plastic bag filled with CO2 ;D But the Myth of CO2 being the main absorber/emitter of radiation is repeated ad nauseam. (as in the uaf post). (The atmosphere is mostly transparent to IR, but will still absorb in proportion to the blackbody curve- warming of the atmosphere is mostly by other means, and then the atmosphere radiates! So there is always more radiation emitted than absorbed.) The CO2 absorption peak scatters its absorption in all directions. I've not seen any real data (other than models) as to how much is thermalised (which will mainly cool the atrmosphere- since radiation will increase over the spread out spectrum) and how much is scattered. The entire blackbody curve of all gases emits radiation. Unlike Mars, where there is a radiation PEAK for CO2 at the poles, there is none for the Earth- due (IMHO) to water being a more efficient emitter due to its higher abundance. Any experiment/calculation about CO2 must allow for the presence of water vapour. ON Mars: Check image on page 3, where there are CO2 Peaks and troughs in different regions at 15nm. (no significant water to interfere) www-mars.lmd.jussieu.fr/granada2003/abstract/ford.pdf
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Post by Ratty on Mar 28, 2009 23:30:50 GMT
Kiwi said: " Any experiment/calculation about CO2 must allow for the presence of water vapour." You know I am just a lurker here trying to get a handle on climate change/global warming and I confess I have not read any IPCC reports **. Do your words above indicate that all IPCC models ignore water vapour? ** because I probably wouldn''t understand them.
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Post by icefisher on Mar 29, 2009 1:25:34 GMT
Better still, use clear cellophane wrap, fill with .08% CO2 and see if the head warms. LOL! Maybe we should send some of these devices to the Catlin Expedition!
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Post by jimg on Mar 29, 2009 6:06:01 GMT
Although I do believe that tin-foil is the helmet of choice for the IPCC.
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Post by poitsplace on Mar 29, 2009 9:35:15 GMT
Kiwi said: " Any experiment/calculation about CO2 must allow for the presence of water vapour." You know I am just a lurker here trying to get a handle on climate change/global warming and I confess I have not read any IPCC reports **. Do your words above indicate that all IPCC models ignore water vapour? ** because I probably wouldn''t understand them. It's hard to know what the numerous IPCC model runs do with anything. It's been pointed out (by some of the people running the models themselves) that using different but perfectly reasonable numbers for the properties of water and other things in the environment the... models may come out with wildly different results. People need to realize...you cannot model what you do not understand. They've only recently discovered the mechanisms driving the regular fluctuations of the climate (about a .4C up/down swing every 50-60 years). They only recently noticed that during a pronounced minimum the outer atmosphere drops by 100 miles or more (potentially decreasing the earth's capture cross section by over 2%). Their assumptions for what they DO know about solar minimums all assumed the solar cycles would be about the same. None of this rather important information is actually in the models. Also if you'll look at the history of the models predictions...you'll see that the models have all been chasing (but never catching up to) reality. All those gloomy, doomy original models that assumed most of the heat from the PERFECTLY NATURAL CYCLE was from CO2. That's why the models continued at those rates. Now even a lot of AGW proponents, faced with the reality of the global cycles, say we're in for 20 more years of cooling. OH! But after that, ZOOM! The built up CO2 forcing will pounce on us. LOL, right, 30 years worth of CO2 forcing (which they roughly estimate to be a minimum of .2C+/decade) is being completely obliterated by what they've said is grossly inferior natural variability of the climate. A sobering thought...if CO2 was largely responsible for the 1942-2007 warming/cooling cycle's overall increase... If the natural variability of the climate is now covering (cooling) an additional .2C per decade for the 2000-2030 cooling period... Then the CO2 forcing has just stopped us from going back into a little ice age.
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Post by socold on Mar 29, 2009 16:16:18 GMT
It's hard to know what the numerous IPCC model runs do with anything. It is hard, it involves reading articles and papers on climate modelling. But not results that contradict significant warming from co2. The wildly different results are reflected by the 1.5-4.5C/doubling climate sensitivty. That is a wild difference, but it sure isn't a skeptic-friendly one. But seeing as we do understand a lot of climate we can model as far as our understanding permits. You assume that 1) either of these things are relevant significant contributors and 2) that "they" is not just one group or one researcher. Each study that comes out doesn't constitute current knowledge. A lot of studies that come and go are simply wrong. This is false.
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Post by jimg on Mar 29, 2009 16:23:34 GMT
socold writes: But seeing as we do understand a lot of climate we can model as far as our understanding permits.
This is not entirely accurate. We model what we "think" we understand of the climate mechanisms.
If we did understand the mechanisms, there would be no need for "correcting" or "tweaking" of the models.
The current "understanding" of a portion of the community is that CO2 drives climate. Which is clearly not agreed upon by the community, just the ones that get the ear of the politicos and media.
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Post by jimg on Mar 29, 2009 16:24:20 GMT
Certainly not enough to hang your hat, or 4th or 5th hat upon.
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Post by socold on Mar 29, 2009 16:38:04 GMT
socold writes: But seeing as we do understand a lot of climate we can model as far as our understanding permits. This is not entirely accurate. We model what we "think" we understand of the climate mechanisms. Exactly. The co2 warming is the result of our best current understanding of climate. Again this is black-or-white, yes-or-no statement. In reality there is a gradient of understanding of mechanisms. Many mechanisms are understood and are not corrected or tweaked. The current understanding of most of the community is that co2 does drive climate. See the climate sensitivity range for doubling of co2. Even the lower end represents significant warming (being an amount larger than the total 20th century warming for example).
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Post by poitsplace on Mar 29, 2009 17:04:10 GMT
The current understanding of most of the community is that co2 does drive climate. See the climate sensitivity range for doubling of co2. Even the lower end represents significant warming (being an amount larger than the total 20th century warming for example). Look, we don't know why the earth cooled during the little ice age or warmed shortly after the little ice age. We don't know why it warmed during the medieval warm period or the roman warm period. We don't know why it cooled between those warm periods. We have some idea as to what seems to synchronize the ice ages but when investigated the variations are quite simply too small...and CO2 has been demonstrated beyond any reasonable doubt to have had little to do with ice age temperature swings. But sure, let's trust the models that show no hints of those things. After all, after only 20 years of tweaking we've finally got them to show...cooling. Bravo...job well done...at least until the climate does something unexpected again.
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Post by socold on Mar 29, 2009 18:36:10 GMT
Look, we don't know why the earth cooled during the little ice age or warmed shortly after the little ice age. We don't know why it warmed during the medieval warm period or the roman warm period. We don't know why it cooled between those warm periods. The reason is that we have insufficient data from those time periods. It's not that climate theory is inadequate - it's that the data is inadequate. It's difficult enough to know what happened let alone move to explain it. The last century is the one century of all in which we have the best observational data. So it stands to reason that if we can explain the climate in any period in Earth's history, it will be the climate of the 20th century. As you mention without amplification from co2 and water vapor the full magnitude of the ice age swings is unexplainable.
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Post by jimg on Mar 29, 2009 20:24:10 GMT
socold writes: The reason is that we have insufficient data from those time periods. It's not that climate theory is inadequate - it's that the data is inadequate. It's difficult enough to know what happened let alone move to explain it.
Isn't this putting the cart before the horse? Actually, we don't even have very much reliable Global data for the 20th century either.
And as you are fond of saying, short time periods don't represent climate, it's only weather. ;-)
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