Airborne dust reduction linked with Atlantic Ocean warming

Monday, 30 March 2009, 14:30 IST
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Washington: Reduced presence of airborne dust and volcanic emissions over the past 30 years are linked with recent Atlantic Ocean warming and has a link to increasing number of hurricanes, according to a new study. For example, the ocean temperature difference between 1994, a quiet hurricane year, and 2005's record-breaking year of storms, was just one degree Fahrenheit. Since 1980, the tropical north Atlantic has been warming by an average of a quarter-degree Celsius (a half-degree Fahrenheit) per decade. Though this number sounds small, it can translate to big impacts on hurricanes, which thrive on warmer water, said Amato Evan, a researcher with the University of Wisconsin-Madison's (UWM) Cooperative Institute for Meteorological Satellite Studies and co-author of the new study. More than two-thirds of this upward trend in the recent decades can be attributed to changes in African dust storm and tropical volcano activity during that time, reports Evan in his study. Evan and his colleagues have previously shown that African dust and other airborne particles can suppress hurricane activity by reducing how much sunlight reaches the ocean and keeping the sea surface cool. Dusty years predict mild hurricane seasons, while years with low dust activity - including 2004 and 2005 - have been linked to stronger and more frequent storms. In the study, they combined satellite data of dust and other particles with existing climate models to evaluate the effect on ocean temperature, said a UWM release.
Source: IANS
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