Is it ensure, insure, or assure?
either of two subtropical atmospheric high-pressure belts that encircle the Earth around latitudes 30-35 N and 30-35 S and that generate light winds and clear skies. Because they contain dry, subsiding air, they produce arid climates in the areas below them. The Sahara, for example, is situated in a horse latitude. The Southern Hemisphere, which has more water area than the Northern, has the more continuous belt of subsiding air. The belts contain several separate high-pressure centres and shift a few degrees away from the equator in summer.