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Thermosphere Contraction Puzzles Scientists

Posted by Soulskill on from the chicken-little-knows-what's-up dept.

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."

6 of 200 comments (clear)

  1. Damn. by BrokenHalo · · Score: 2, Interesting

    I was hoping for some comment that might shed some (presumably ionising) light on this issue, since TFA offers no suggestions. Instead, we have a series of boring troll posts.

    Oh well, I'll just move on, nothing to see here...

  2. ARRL skip thought by moo-shim · · Score: 2, Interesting

    I wonder that the Amateur Radio low power operators have to say about the "skip" signals? That is when a radio wave gets caught in a "corridor" up there and "bounces" in there a long way before coming back to earth. The compression should have some sort of effect on them.

  3. Re:Great by Burnhard · · Score: 3, Interesting

    What is it with you people? Scientists have said that they have observed a change in the Thermosphere that they can't explain . What is it about the phrase "they can't explain" that leads you to believe it's caused by Carbon Dioxide?

  4. Re:Very easy to explain.. by Arlet · · Score: 3, Interesting

    Europe may have had a cold winter, but globally the period Dec 2009-Feb 2010 was warmer than average. Similarly, the spring/early summer period was also warmer than average.

    As far as the temperature on any given point on the globe, it's a combination of weather and climate. Global warming has pushed the averages up a little, but daily weather will always be the major factor in the temperature swings.

  5. Are we really sure about CO2? by rs79 · · Score: 1, Interesting

    http://rs79.vrx.net/opinions/observations/significant/2010/environment/

    --
    Need Mercedes parts ?
  6. Re:Not temperature - density by Arlet · · Score: 3, Interesting

    Going from 280 to 380 ppm is a relative increase of 35%. That's certainly a significant increase. Don't get distracted by the relatively small overall concentration in the atmosphere. This is completely irrelevant. What matters is the total mass of CO2 the light passes through from the sun to the earth's surface. This total mass has been increased by 35%.