Science: East Coast is getting more, stronger hurricanes
The 15 named tropical storms this summer, including the devastating Hurricane Katrina, have left many feeling like hurricane season is hitting harder than it used to. Now a report in this week's Science journal is giving them ground to stand on, adding credibility to the theory that hurricanes are getting stronger and, in some places, more frequent, and that global warming could be to blame.
Using satellites, scientists have been able to track the number of hurricanes each year and their strength for about three decades. In that period, the number of hurricanes worldwide has remained constant, though the percentage of those storms that are very strong–classified as category 4 or 5–has doubled. The researchers said that finding was "astonishing."
The likely cause, they said, was an increase in ocean surface temperatures, which have also gone up globally in that same period and are likely due to an overall increase in the Earth's temperature. As ocean surface temperatures rise, there is more evaporation.
"It's like putting more and more fuel into the engine," says Peter Webster, one of the authors on the paper and a professor at the Georgia Institute of Technology.
While the frequency of storms has not increased globally, one particular area is seeing more hurricanes–the North Atlantic, the area that includes the East Coast of the United States. Webster said he's not sure why this is, though he thinks it likely is caused by both global warming and the natural variations in hurricane frequency from year to year.
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