Dust Sweeps Across the Atlantic

A burst of Saharan dust has moved over the Atlantic Ocean from the African continent.

Although it's not an uncommon occurrence, this particular late-July display of the so-called Saharan Air Layer (SAL) is quite large and vivid. The first satellite image in the slideshow below shows the brown dusty air near Africa on July 30, 2013 in contrast to the darker ocean surface below.

According to NOAA, the Saharan Air Layer (SAL) is typically found at altitudes between 5,000 and 20,000 feet and is transported westward by prevailing easterly winds over the tropical Atlantic Ocean during the summer.

NOAA says that the SAL can impact the development of tropical storms and hurricanes in a few ways:

• The dry air can create downdrafts (sinking air) around the storm, which may result in the weakening of tropical systems.
• Strong winds associated with the SAL can contribute to increased vertical wind shear, which makes the environment hostile for tropical development.
• The role dust plays in tropical storm and hurricane intensity is not known, however some research says it may impact cloud formation.

(MORE: Dr. Jeff Masters Explains the SAL)

In some cases, the dust has been tracked as far west as the Caribbean Sea, southern Florida and the Gulf of Mexico. The dust particles can contribute to hazy skies at times during the summer in the Caribbean Islands and in southern Florida. It takes about a week for the dust to travel from near Africa to Florida and the Caribbean.