The distribution of major desert regions on Earth is primarily controlled by several factors, including latitude, prevailing wind patterns, ocean currents, and topography. For example, many of the world's largest deserts are located in or near the tropics, where the air is warm and dry due to the high amount of solar radiation received at these latitudes. Prevailing wind patterns also play a role in desert formation, as winds blowing from the ocean onto land tend to lose their moisture as they travel over long distances, resulting in arid conditions. Similarly, ocean currents can affect the climate of coastal regions, with cold ocean currents often creating dry, desert-like conditions. Finally, topography can also play a role in desert formation, as mountain ranges can create rain shadows that block moisture from reaching certain areas, resulting in desert conditions.