Wednesday, June 15, 2011

Solar forecast hints at a big chill

The sun unleashes a powerful solar flare from the right side of its disk on June 7, as seen in this image from NASA's Solar Dynamics Observatory. Scientists say the sun is heading toward a peak in its activity cycle in 2013 or so, but may enter a period of hibernation afterward.

By Alan Boyle

The latest long-range space forecast predicts a prolonged drop in solar activity after the next peak — and scientists say that might cool down temperatures here on Earth, or at least slow down the warming trend a bit.

Scientists have studied sunspots and the sun's 11-year activity cycle for 400 years, and they're getting increasingly savvy about spotting the harbingers of "space weather" years in advance, just as meteorologists can figure out what's coming after the next storm.

Storms from the sun are expected to build to a peak in 2013 or so, but after that, the long-range indicators are pointing to an extended period of low activity — or even hibernation.

"This is important because the solar cycle causes space weather ... and may contribute to climate change," Frank Hill, associate director of the National Solar Observatory's Solar Synoptic Network, told journalists today.

In the past, such periods have coincided with lower-than-expected temperatures on Earth. The most famous example is the Maunder Minimum, a 70-year period with virtually no sunspots from 1645 to 1715. Average temperatures in Europe sank so low during that period that it came to be known as "the Little Ice Age." Full article here

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