A new dust storm began blowing off the west coast of Africa on July 18, 2009. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite took this natural-color picture at 11:35 UTC on July 19, 2009, as the dust plumes continued moving westward over the Atlantic Ocean. The tan dust appears thickest off the coast of Senegal. Near Cape Verde, a thin haze of dust appears to mingle with clouds.
The dust plumes in this storm likely originated inland from the coast. Large sand seas cover much of Mauritania and neighboring Mali. The dust may have arisen in those sand seas, or it may have arisen farther inland, and traveled over much of the Sahara Desert.