Earth's Upper Atmosphere Cooling Dramatically

Earth's Upper Atmosphere Cooling Dramatically
(Space.com) December 17, 2009, By Andrea Thompson
When the sun is relatively inactive — as it has been in recent years — the outermost layer of Earth's atmosphere cools dramatically, new observations find. The results could help scientists better understand the swelling and shrinking of our planet's atmosphere, a phenomenon that affects the orbits of satellites and space junk. The data, from NASA's TIMED mission, show that Earth's thermosphere (the layer above 62 miles or 100 km above the Earth's surface) "responds quite dramatically to the effects of the 11-year solar cycle," Stan Solomon of the National Center for Atmospheric Research in Boulder, Colo., said here this week at the annual meeting of the American Geophysical Union.