Describe the atmospheric circulation for two places where you are likely to find deserts, and explain why these regions are relatively warm and dry.

In the leeward side of a mountain

30° N/S of the equator

are the two places where you are likely to find deserts,

Explanation:

IN the first case, the areas in the leeward side of a mountain are warm and dry because they receive very low rainfall. When a warm air mass with moisture approaches the mountain from the windward side, the air mass is pushed up and it cools and the moisture condenses, This extracts the moisture that falls as precipitation on the leeward side. When this air mass crosses over the mountain, it is already dry and there is little moisture left as it crosses into the leeward side.

This is the case with 30° N/S of the equator. When the air mass, of the Hadley cell, rises at the equator due to lowered density from the higher temperatures at the equator, it cools and the moisture in it condenses causing precipitation in the equatorial region. This air mass them moves polewards and sinks at it approaches about 30° N or S. The air mass has little moisture left in it and as it sinks it causes a high pressure system that is not associated with rainfall. This is why these latitudes have many deserts.