A harmattan dust storm was blowing strong on February 28, 2014, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this image. The yellow dust is concentrated largely over the Cape Verde Islands, where the mountain topography is creating swirling eddies and triangular wakes in the dust cloud. West Africa frames the right edge of the image, and distinct plumes of dust blow west from Senegal and Mauritania. The dust storm had a long reach. By March 4, a faint yellow haze lingered over the Caribbean.
The storm is not unusual in its reach. Hundreds of millions of tons of dust blow out of Africa every year, reaching the Atlantic, Caribbean, and Gulf of Mexico. The dust fertilizes ocean waters, feeding plankton growth, but it may also carry fungus and disease-causing microorganisms that damage coral reefs. On land, the dust itself is a health hazard when inhaled, and it has been found to carry chemical contaminants, including pesticides. Such storms aren’t limited to winter harmattan storms. The southwest monsoon keeps the dust away from the ground in the summer, but winds still blow the dust out of Africa higher in the atmosphere throughout the year.
References
- NASA Earth Observatory (2013, August 29) Tracking dust across the Atlantic.
- Prospero, J.M. and Mayol-Bracero, O.L. (2013, September) Understanding the transport and impact of African dust on the Caribbean basin. Accessed March 4, 2014.
- U.S. Geological Survey (2013, July 29) The effects of African dust on coral reefs and human health. Accessed March 4, 2014.
NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC. Caption by Holli Riebeek.
- Instrument:
- Terra - MODIS - NASA
