Sunspot-Hurricane Link Proposed

From Nature News:

Controversial research hints that solar cycle affects cyclone intensity.

A new study suggests that more sunspots mean less intense hurricanes on Earth. But many hurricane experts are cool on the idea.

James Elsner, a climatologist at Florida State University in Tallahassee, has analyzed hurricane data going back more than a century. He says he has identified a 10- to 12-year cycle in hurricane records that corresponds to the solar cycle, in which the Sun's magnetic activity rises and falls.

The idea is that increased solar activity - associated with sunspots - means more ultraviolet radiation reaching the Earth's upper atmosphere. That warms the airs aloft and decreases the temperature differential between high and low elevations that otherwise would fuel hurricanes.

"Our results indicate that there is an effect in the intensity of storms due to the higher temperatures aloft," says Elsner, who published the results on 19 September in Geophysical Research Letters1.

He says the statistical analysis suggests a 10% decrease in hurricane intensity for every 100 sunspots. At the peak of its cycle, the Sun might exhibit around 250 sunspots.

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