Dust over West Africa

Dust continued blowing over western Africa on April 30, 2012.. An especially thick plume of dust blew over southwestern Mali and Guinea.

At least some of the dust appeared to originate in Mali, the country in the northeast of this image. Senegal lies in the northwest corner of the image, and Guinea is to the south. The large, landlocked nation of Mali receives little rainfall, but because northeastern Mali lies within the Sahara, and southwestern Mali lies within the Sahel, the country has a north-south rainfall gradient, with more precipitation falling in the south. By April 2012, however, southwestern Mali was coping with severe drought.

Mali’s rainy season lasts from June to August, but the rainy season of 2011 experienced just one month of rainfall. The unusual aridity in late 2011 and early 2012 may have increased the odds of dust storms by drying out marsh and river sediments in southwestern Mali. Meanwhile, the vast sand seas of northeastern Mali can regularly contribute to dust storms. (EarthObservatory)