Sand Storm over the Mediterranean
A strong wind blows sand and dust across the Mediterranean Sea from the Algerian Desert, located in the northeast section of the Sahara Desert, to Sardinia, Corsica and the northern of the Italian Peninsula on 9 and 10 September 2008 in this Envisat image.
Sandstorms are usually the result of atmospheric convection currents, which form when warm, lighter air rises and cold, heavier air sinks (Scirocco). The cold air in this image is visible stretching from the left side of the image down to the bottom and swirling back towards the north just above Tunisia, while the warm air current is seen blowing sand from south to north.
Dust from the Sahara Desert can be transported over thousands of kilometres by convection currents, which also cause other meteorological conditions, such as thunderstorms. Because the Sahara, where sandstorms are very common, is a major source of mineral dust, large concentrations of the dust can be found in the tropical Atlantic and the Caribbean.
Saharan dust plays an important role in the Mediterranean region because it is the major source of mineral nutrients for phytoplankton – the basic food on which all other marine life depends.