Saharan dust

From WikiCover

Announced December 14, 2007, NASA satellites have provided evidence that the chilling effect of dust was responsible for one-third of the drop in North Atlantic sea surface temperatures between June 2005 and 2006, possibly contributing to the difference in hurricane activity between the two seasons.

Heat from warm ocean surfaces is known to fuel hurricanes, leading to stronger and more frequent storms. During the hurricane season of 2006, however, sea surface temperatures in the North Atlantic remained relatively cool and the season saw only five hurricanes, compared to fifteen hurricanes in 2005 when the ocean surface was warmer.

Now, William Lau and Kyu-Myong Kim at NASA's Goddard Space Flight Center, Greenbelt, Maryland, show that airborne Saharan dust over the Atlantic was likely responsible for much of the temperature drop, effectively blocking sunlight from reaching the ocean's surface. According to their research, dust accounted for thirty to forty percent of the drop in sea surface temperature between June 2005 and 2006, the team reported December 8, 2007 in the American Geophysical Union's Geophysical Research Letters. The finding provides the first quantitative estimate of dust's role in cooling the entire North Atlantic and brings attention to dust as a potentially important influence on hurricane activities.

To investigate the dust and sea surface temperature link, Lau and Kim calculated the cooling pattern that Saharan dust should produce on sea surface temperatures from the sun-blocking effect and compared the results to observed temperature patterns.