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Thermosphere Contraction Puzzles Scientists
The thermosphere layer of earth's atmosphere begins 80 to 90 kilometers above the surface and extends several hundred kilometers into the sky; it is the home to numerous satellites and the International Space Station. It is known that the thermosphere occasionally cools and contracts, but a recent study of satellite orbital decay (due to light atmospheric drag) found that the contraction during 2008 and 2009 was significantly more severe than expected, leaving researchers at a loss for how to explain it. From Space.com:
"This type of collapse is not rare, but its magnitude shocked scientists. 'This is the biggest contraction of the thermosphere in at least 43 years,' said John Emmert of the Naval Research Lab, lead author of a paper announcing the finding in the June 19 issue of the journal Geophysical Research Letters. 'It's a Space Age record.' The collapse occurred during a period of relative solar inactivity — called a solar minimum from 2008 to 2009. These minimums are known to cool and contract the thermosphere, however, the recent collapse was two to three times greater than low solar activity could explain."
The sky is falling in... literally!
On the one hand, it's reported this is not rare. On the other hand, we've got plenty of sensationalistic language: "significantly more severe", "researchers at a loss", "collapse", "its magnitude shocked scientists".
So, is it the usual news cycle hype reporting on a puzzling phenomenon, or is there a reason to be alarmed?
Think of insulation. Insulation can keep heat in, and it can also keep heat out. Insulation will keep your house warm in the winter, and also cool in the summer. It's not that hard to understand, is it?
Although CO2 may be causing cooling high in the troposphere, it's keeping the surface of the Earth warm. So far, 2010 is the warmest year on record, with Arctic and Antarctic ice continuing to melt, despite low solar activity.
What a fool believes, he sees, no wise man has the power to reason away.
Actually it's likely related to global warming, since CO2 emits light at a different wavelength than it absorbs it, it sometimes causes the thermosphere (and other layers) to cool and contract by the time the light gets to the outer layers. There are climate models that predict this. The heat is absorbed at low altitudes and not emitted at high altitudes.
Actually I just made that up, but it sounded good, didn't it? Right? I'm sure we can blame it on pollution somehow.
Qxe4
doors, do they let people in, or do they let people out? Which is it?
windows, do they let light in, or do they let light out? We can't win!
CO2 is denser than air so naturally the atmosphere compacts under gravity as the density increases.
Utterly incorrect. CO2 levels rising dramatically doesn't mean the percentage composition of CO2 in the atmosphere has changed by a large number. The atmosphere is still less than .5% CO2 today; even if it had started at 0% CO2, adding .5% concentration of something only half again as heavy (or dense, if you prefer; not that dense and heavy are synonyms but either way my point stands) as the vast majority of the atmosphere would not logically explain "the biggest contraction of the thermosphere in at least 43 years" without some serious synergy compounding the effect of that minimal impact on atmospheric density.
Furthermore, a given swath of the atmosphere is all roughly the same density; it's not like there's this big fat pocket of air that weighs 0.1 g/L and this other pocket a mile away at the same altitude that weighs 0.19 g/L. Diffusion dictates that CO2 could change the density of the air only as much as it changes the average density of the entire atmosphere (at a given altitude) once completely diffused into all the other stuff. You could jack the atmosphere up to 10% CO2, 20 times what it's ever been in the last billion years, and I doubt you could explain these contractions with simply density arguments.
Also, TFA mentions CO2 - not in any conjunction whatsoever with your insane reason for mentioning it, but it does mention CO2 - and says "Even when we take CO2 into account using our best understanding of how it operates as a coolant, we cannot fully explain the thermosphere's collapse." Note that they're talking about CO2 cooling the upper atmosphere, not about density.
Whoever marked the parent as informative is a moron.
Definitely, and there's at least 4 of them apparently. 4 people who felt compelled to tell us this was good information but couldn't remember anything about 101 level chemistry. How the fuck did they pretend to know it was good information if they can't see through something that stupid?
Interestingly, global warming does cause colder winters. The cause of those colder winters is the melting of the ice caps.
More heat in the atmosphere means more energy, which causes stronger winds and quicker circulation. Cold air from the north pole travel faster to Europe and therefore has less time to warm in the way.
Those colder winters are more than balanced by hotter summers, we are spending away our ice reserves. It's like when you spend more than you earn. Your having more money to spend does not mean you're getting richer.
No, we had not. When you say something like that I wonder if you're living in Europe at all - or maybe you're counting on your readers to not be in Europe?
Winter in Europe, December to February, were below the average for the period 1951-1980 (the standard reference period). But already in spring, March to May, it was back above it.
Another issue: the amount of snowfall depends primarily on water vapor in the atmosphere. As long as there's freezing temperatures, more moisture means more snow. More cold below zero degrees celsius does not cause more snow. A very basic prediction of climate modeling is that water vapor in the atmosphere will increase as temperature increases. So record cold might be unexpected from a climate science perspective; record snowfall would not.
xkcd is not in the sudoers file. This incident will be reported.
when the contractions are 5 minutes apart
I wonder by which definition you say the Arctic ice cap is in "decline", but not melting?
The Antarctic ice sheet is shrinking, not growing. It's losing volume, which is the only significant definition of size when one considers climate issues. It's losing volume the only way a polar ice cap can lose volume, by melting. But, of course, you'll never know this if you have only one news source.
Warmer oceans cause increased water evaporation, which then precipitates as snow or rain. Considering that a large part of Antarctica is still well below freezing point, it's only natural that *some* regions of Antarctica have had more snowfall caused by global warming. Yes, global warming does cause both more snowfall and colder winters. Which is more than offset by hotter summers and increased ice melting.
We had 8 months of winter in Europe, with record snow down to Spain and temperatures lower than they were in the last 30 years. Were constantly reminded that it was a seasonal event, weather, that had nothing to do with climate.
After a mere 3 weeks of summer, with record hot temperatures, the media is already reviving the global warming mantra.
Here in the US, the conservative pundits declared global warming a hoax this past winter when we had record snowfalls. Now we're having record heat this summer and the conservative pundits haven't said a word. Media stupidity about global climate change goes both ways.
Tired of being "punished" by the Slashdot $rtbl since 2002. I'm now over at http://soylentnews.org/ .