Role of African storms explored in American hurricanes

U.S. researchers have discovered new insights into the origins of hurricanes in the nation's south.

Scientists from NASA's Marshall Space Flight Centre and the U.S. National Oceanic and Atmospheric Administration (NOAA) are conducting a study to see how tropical waves in Africa relate to hurricanes in the U.S.

The scientists realized that some clusters of tropical waves from Africa turn into hurricanes in the U.S., and some do not.

Of the ones that do form into named tropical storms, 60 percent can be accounted for by African thunder storms, according to NOAA hurricane researcher Jason Dunion.

Seven to ten times a month, clusters of storms roll off Africa's West Coast and make their way across the Atlantic, although many of them don't turn into hurricanes.

Upon further study, the scientists say a warm, dry, and dusty layer of sand blowing off the Sahara seems to stop or at least delay some of the hurricanes.

This is because the layer mixes with tropical waves, breaking up the thunderclouds' ability to transfer energy from the ocean to the atmosphere, according to the scientists.

Also, the scientists claim winds blowing at about 40 to 80 kilometres an hour in the Sahara may also help to break apart the thunderclouds.

The research is part of the African Monsoon Multidisciplinary Analyses (AMMA).

Photography: Visible Earth NASA Images

Source: Discovery Channel Reports, August 3 edition