DUST TO DUST: Dust storms form primarily during the summer and winter months in the Sahara, but some years they barely form at all, and scientists are unsure why. Attention has turned to the environmental impact of dust since it became clear that in some years, millions of tons of sand rise up from the Sahara Desert and float across the Atlantic Ocean, sometimes in as few as five days. The sand rises when hot desert air collides with the cooler, dryer air of the Sahel region -- just south of the Sahara -- and forms wind. As particles swirl upwards, strong trade winds blow them west into the northern Atlantic. It's also possible that these dust storms might suppress the development of hurricanes. Sahara Desert dust storms impact the atmosphere in three ways: (1) dust storms are extremely dry and cover a large area; (2) dust storms have strong winds; and (3) dust absorbs heat and prevents cloud formation. Dry, dust-ridden layers of air may help to dampen brewing hurricanes, which need heat and moisture to fuel them. That effect could also mean that dust storms have the potential to shift a hurricane's path further to the west, giving it a higher chance of hitting US soil.
The American Meteorological Society and the American Geophysical Union contributed to the information contained in the TV portion of this report.