Paper on the relationship between African dust and hurricane activity published in Atmospheric Chemistry and Physics

Dust layer associated with the Saharan Air Layer. Photo taken from the NOAA G-IV northeast of Barbados during a Saharan Air Layer Experiment mission into Hurricane Helene on Sep 16, 2006. Small cumulus clouds can be seen poking through the tops of the dust layer, which is seen as a milky white haze. Photo credit: Jason Dunion, University of Miami/CIMAS – NOAA/HRD.

Summary: Saharan dust outbreaks emerge from the coast of Africa every 3-5 days during the summer, can reach as far west as the United States and Central America, and cover vast areas of the Atlantic (sometimes as large as the lower 48 United States). These outbreaks, also known as the Saharan Air Layer, contain dry, dusty air and unfavorable winds that can suppress tropical cyclone activity. This study examines the relationship between Saharan dust and tropical cyclone activity over different regions of the North Atlantic Ocean for the years 2003-2018.

GOES-16 GeoColor satellite image showing a large Saharan dust outbreak overspreading Central America, the western Gulf of America, and the southeastern U.S., and a second dust outbreak spanning from Africa to the West Indies and eastern Caribbean Sea. Saharan dust is seen as a brownish haze in this GeoColor satellite image from June 26, 2020.

■ Important Conclusions:

Atlantic hurricane seasons with more Saharan dust outbreaks tend have less tropical cyclone activity.
Year-to-year fluctuations in the amount of dust over the Atlantic are linked to shifts in large-scale patterns of winds, moisture, and sea surface temperature across the basin, factors that are known to influence tropical cyclone activity.

The full article is available at https://acp.copernicus.org/articles/20/15357/2020/. For more information, contact aoml.communications@noaa.gov.