washingtonpost.com
Science
Notebook
Monday, May 28, 2007; A06
Ocean Temperatures Not the Only Determining Factor in Hurricanes
The eastern Caribbean has experienced periods of intense hurricane activity during centuries of unusual cold as well as unusual warmth -- suggesting that ocean temperatures are not the only, or most important, factor determining how the storms are spawned and how strong they become.
Researchers at Woods Hole Oceanographic Institution in Woods Hole, Mass., came to that somewhat surprising conclusion by analyzing coarse, sandy deposits at the bottom of a lagoon on the Puerto Rican island of Vieques and in the New York area. That work, which allowed them to produce a 5,000-year record of hurricane activity, found a strong correlation between the intensity of storms along the Atlantic coast and the strength or weakness of the El Niño water temperature effect in the Pacific Ocean, as well as the intensity of West African monsoons.
The findings add to the complex puzzle scientists are trying to solve regarding the origins of especially destructive hurricanes. Some believe that the warming of ocean temperatures, as a result of greenhouse gases set loose by human activity, has led to stronger and more destructive hurricanes, while others say the data do not support that conclusion.
In their paper in the journal Nature, Jeffrey P. Donnelly and Jonathan D. Woodruff conclude that the issue remains unsettled -- that the occurrence of intense hurricane activity even when global and ocean temperatures are relatively low does not necessarily mean that global warming will not lead to greater hurricane dangers. Rather, they say it means that patterns of hurricane intensity can change significantly without a global ocean temperature rise, and that with the increase the effect could be greater.
-- Marc Kaufman |
