Monday, March 28, 2011

"Global Blowing"?


The world has gotten stormier over the past two decades—and the reason is a mystery, a new study says.


In the past 20 years, winds have picked up around 5 percent on average.

Extremely strong winds caused by storms have increased even faster, jumping 10 percent over 20 years, according to the new analysis of global satellite data.

The study, the first to look at wind speeds across such a large swath of the planet, bolsters some earlier findings, according to study leader Ian Young, of the Swinburne University of Technology in Melbourne, Australia.

"Some regional studies had found similar results, so we suspected there may be an increasing trend," Young said.

(See "Extreme Ocean Storms on the Rise, Tremors Show.")

Bat-Like Sonar Tracks Wind Speeds

With the development of satellite and radar technology, the planet's temperature and rainfall have been tracked like never before.

Other aspects of the climate, however, haven't gotten as much attention.

To create a record of wind measurements around the world, Young and colleagues assembled global satellite measurements dating back to 1985.

The team drew on records from satellites that used radar altimeters, which work similarly to bats' echolocation, or natural radar.

The orbiting satellites shoot radio waves at Earth and listen for the echoes that bounce back into space.

When winds are blowing hard, the radar echoes are fainter, giving a measure of how strong the wind is blowing over the oceans.

Windy Trend Linked to Global Warming?

It's not yet clear whether the windier trend is due to global warming, or if it's part of a cyclical pattern, said Young, whose research appeared Friday in the journal Science.

(Also see "Extreme Storms and Floods Concretely Linked to Climate Change?")

"If this is related to global warming—and this is speculation—it indicates that either the intensity of storms is increasing or the frequency of storms is increasing," he said.

If the winds keep up, they could impact "engineering design of coastal and offshore structures, coastal erosion, and marine ecosystems.

Mason Inman
for National Geographic News
Published March 28, 2011

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