Study: Water color could affect storms

Published: Aug. 13, 2010 at 7:01 PM

WASHINGTON, Aug. 13 (UPI) -- A change in the color of ocean waters could have a significant impact on the number and severity of hurricanes around the world, U.S. researchers say.

A simulation of such a change in the North Pacific found hurricane formation decreasing by 70 percent, a significant drop for a region where half the world's hurricane force winds are reported, an American Geophysical Union release said Friday.

The formation of typhoons, or hurricanes, is heavily affected by the presence of chlorophyll, the green pigment that allows tiny organisms called phytoplankton to convert sunlight in to food and which can contribute to the ocean's color, the release said.

"We think of the oceans as blue, but the oceans aren't really blue, they're actually a sort of greenish color," said Anand Gnanadesikan, a researcher with the National Oceanic and Atmospheric Administration. "The fact that (the oceans) are not blue has a (direct) impact on the distribution of tropical cyclones."

In a computer model of the region, when chlorophyll levels were set to zero, the absence of chlorophyll affected hurricane formation by modifying air circulation and heat distribution patterns both within and beyond the modeled circulation patterns in the ocean waters.

In the no-chlorophyll scenario, sunlight penetrates deeper into the ocean, leaving the surface water cooler. The drop in temperature in the model affects hurricane formation, as cold water provides less energy and air circulation patterns change, leading to more dry air aloft which makes it hard for hurricanes to grow.

http://www.upi.com/Science_News/2010/08/13/Study-Water-color-could-affect-storms/UPI-81641281740499/