In late January, 2014 heavy winds drove a thick band of dust across Libya and the Mediterranean Sea. The Moderate Resolution Imaging Spectroradiometer (MODIS) flew over the region on January 31 and captured this true-color image of the event.
A wide bank of white clouds can be seen in the southeast corner of the image. Behind the cloud line a broad plume of tan desert sand sweeps towards the northeast from arid regions in Libya across the deep blue of the Mediterranean Sea. In some areas, especially over the Mediterranean, the dust is so thick that the land and sea beneath the plume is hidden from view. Dust can also be seen across Tunisia (northwest) and Algeria (southwest).
Dust storms most often occur in regions with little vegetation and low precipitation – most often in deserts when no rain has fallen recently. Libya’s interior has ideal conditions for the formation of dust storms, as much of the land is largely arid to semi-arid with little natural vegetation.
In order for dust to break its bonds with the Earth and be lifted into the air, wind speeds typically need to reach at least 17 mph (27 km/h). Once a dust storm starts, however, dust can remain in the air at lower speeds. On January 31, according to Wunderground.com, winds were gusting up to 21 mph (24 km/h) in Tripoli, Libya.