A recent study suggests that dust storms from West Africa may filter the sun's rays enough to cool Atlantic Ocean water temperatures, and that cooling likely has a direct impact on hurricane activity in the Atlantic Ocean.
According to ScienceDaily, the study, conducted by scientists at the University of Wisconsin-Madison Department of Atmospheric Science, says that strong winds carry dust particles across Africa and into the air over the Atlantic Ocean. The dust can be thick enough to decrease the amount of the sun's energy that reaches the water's surface. ScienceDaily also says that the study indicates a large amount of dust that cooled Atlantic waters is also the likely cause for the for the overall lack of activity in the 80s and 90s.
The study suggests that the 2007 hurricane season may have been hampered by an especially dusty spring and early summer; more dust was noted in 2007 than any other year since 1999.
The dust can be observed using weather satellites and can be forecast to help in hurricane season forecasts.