Sahara Dust Rains on UK

Being perched off the northwest edge of Europe means that people in the UK are not often reminded of the vast Sahara desert situated only a few thousand miles to the south.

This great desert is located under a descending branch of the global atmospheric circulation, that is, a point at which air, having been heated close to the equator and then blown north or southwards high in the atmosphere, then descends back to the surface. This leads to a hot, dry climate in the Sahara with little vegetation.

Strong winds can lift dust from the bare desert soils, which can then be carried by the wind for thousands of kilometres. This dust is in fact a natural part of the earth system, providing essential nutrients to plankton in the oceans and plants growing as far away as the Amazon.

Particularly large and intense dust storms occur quite often over the Sahara in spring, as weather fronts trailing from mid-latitude weather systems over the northern part of the Sahara generate winds strong enough to lift up the sands. It’s more unusual that dust from the Sahara is transported directly to the UK, but when it does, rain can bring the dust back down to earth.