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6,000 years ago the Sahara Desert was tropical, so what happened ?

ScienceDaily (November 30, 2016)

Titre : 6,000 years ago the Sahara Desert was tropical, so what happened ?

ScienceDaily (November 30, 2016)

As little as 6,000 years ago, the vast Sahara Desert was covered in grassland that received plenty of rainfall, but shifts in the world’s weather patterns abruptly transformed the vegetated region into some of the driest land on Earth. A Texas A&M university researcher is trying to uncover the clues responsible for this enormous climate transformation — and the findings could lead to better rainfall predictions worldwide.
The Hadley circulation is a tropical atmospheric circulation that rises near the equator. It is linked to the subtropical trade winds, tropical rainbelts, and affects the position of severe storms, hurricanes, and the jet stream. Where it descends in the subtropics, it can create desert-like conditions. The majority of Earth’s arid regions are located in areas beneath the descending parts of the Hadley circulation.

Story Source  : Texas A&M University.

Annonce (ScienceDaily)

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