Whenever I visit the Sahara I am struck by how sunny and hot it is and how clear the sky can be. Aside from a few oases there is little vegetation, and most of the world’s largest desert is covered with rocks, sand and sand dunes. The Saharan sun is powerful enough to provide Earth with significant solar energy.
Every year, trade winds over the Sahara Desert sweep up huge plumes of mineral dust, transporting hundreds of teragrams — enough to fill 10 million dump trucks — across North Africa and over the Atlantic Ocean. This dust can be blown for thousands of kilometers and settle in places as far away as Florida and the Bahamas.