© NASAImage of the Earth's atmosphere.
Large changes in the sun's energy output may drive unexpectedly dramatic fluctuations in Earth's outer atmosphere.Results of a study published today link a recent, temporary shrinking of a high atmospheric layer with a sharp drop in the sun's ultraviolet radiation levels.
The research, led by scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., and the University of Colorado at Boulder (CU), indicates that the sun's magnetic cycle, which produces differing numbers of sunspots over an approximately 11-year cycle, may vary more than previously thought.
The results, published this week in the American Geophysical Union journal
Geophysical Research Letters, are funded by NASA and by the National Science Foundation (NSF), NCAR's sponsor.
"This research makes a compelling case for the need to study the coupled sun-Earth system," says Farzad Kamalabadi, program director in NSF's Division of Atmospheric and Geospace Sciences, "and to illustrate the importance of solar influences on our terrestrial environment with both fundamental scientific implications and societal consequences."
The findings may have implications for orbiting satellites, as well as for the International Space Station.