NASA MODIS Image of the Day: December 30, 2011 – Saharan dust over the Atlantic Ocean
On December 22, 2011 strong winds carried sand from the Sahara Desert hundreds of miles off the coast of western Africa and out over the Atlantic Ocean.
The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured this true-color image of the blowing sand at 12:40 UTC on that same day.
Tan Saharan dust can be seen layered under the white clouds in a long arc running from north to south. In some areas, the clouds cast shadows on the underlying dust. In the south, the dust widens and lightens in color as it spreads across the ocean waters. The Cape Verde Islands lie in the mid-Atlantic Ocean some 450 kilometers (300 miles) off the west coast of Africa. They can be seen in the lower right side of this image, surrounded by dust. The prevailing wind here is from the northeast to the southwest. As the wind blows against the tall volcanic peaks on the islands, the flow is interrupted. This results in pockets of clear air just leeward of the islands, as well as intricate patterns of dust and clear air which are created by the turbulent airflow behind the islands.
