Sun buffets Earth with streams of energy even during sunspot minimums

Challenging conventional wisdom, a new study finds that the earth was bombarded last year with high levels of solar energy at a time when the Sun was unusually quiet and sunspots had virtually disappeared, says this article in Science Daily.

18 Sep 09 – “The Sun continues to surprise us,” says NCAR scientist Sarah Gibson, the lead author. “The solar wind can hit Earth like a fire hose even when there are virtually no sunspots.”

Gibson and her colleagues analyzed high-speed streams within the solar wind that carry turbulent magnetic fields out into the solar system.

When those streams speed by the earth, they intensify the energy of the planet’s outer radiation belt. This can create serious hazards for weather, navigation, and communications satellites, the article says, and threaten astronauts in the International Space Station. “Auroral storms light up the night sky repeatedly at high latitudes as the streams move past, driving mega-ampere electrical currents about 75 miles above Earth’s surface.”

Until now, scientists had thought that the streams largely disappeared as the solar cycle approached minimum.

Now scientists wonder how the streams might have affected the earth during previous periods of low sunspot activity such as the Maunder minimum, from about 1645 to 1715.

See entire article, entitled “Solar Cycle Driven By More Than Sunspots; Sun Also Bombards Earth With High-speed Streams Of Wind”
http://www.sciencedaily.com/releases/2009/09/090917131556.htm

Thanks to Eunice Farmilant for this link


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