Simplify the following text for a Grade 11 native English-speaking person.
Original: The Saharan Air Layer ( SAL ) is an intensely dry , warm and sometimes dust-laden layer of the atmosphere which often overlays the cooler , more-humid surface air of the Atlantic Ocean .
Simplified: The Saharan Air Layer ( SAL ) is an intensely dry , warm and sometimes dust-laden layer of the atmosphere which often overlies the cooler , more-humid surface air of the Atlantic Ocean .