English: Saharan sand blowing off the coasts of Mauritania and Senegal. Two dust plumes blow toward the south west, one plume stretching possibly 150 kilometres off the coast, and the other plume forming an arc that reaches all the way to Cape Verde. Thinner but larger plumes of dust hover over the Atlantic west and north of the island archipelago. Although this image shows dust immediately off the coast of West Africa, a layer of dust from storms such as this often travels virtually intact to the other side of the Atlantic. This layer of dry, hot, dusty air is called the Saharan Air Layer.