Dust Causing Atlantic Ocean Warming?
Since 1980, the tropical North Atlantic has been warming by an average of a half-degree Fahrenheit (a quarter-degree Celsius) per decade.
While that number may sound small, it can translate to big impacts on hurricanes, which are fueled by warm surface waters, said study team member Amato Evan of the University of Wisconsin-Madison.
For example, the ocean temperature difference between 1994, a quiet hurricane year, and 2005's record-breaking year of storms (including Hurricane Katrina), was just 1 degree Fahrenheit.
Evan and his colleagues had 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 new study, the researchers investigated the exact effect of dust and volcanic emissions on ocean temperatures.
They combined satellite data of dust and other particles with existing climate models and calculated how much of the Atlantic warming observed during the last 26 years could be accounted for by simultaneous changes in African dust storms and tropical volcanic activity, primarily the eruptions of El Chichón in Mexico in 1982 and Mount Pinatubo in the Philippines in 1991.
