Air movements at tropical latitudes
Let us now explain air movements at tropical latitudes. The surface air that rushes to fill the equatorial void from the north is deflected to the right and becomes the north-east trade wind. It meets similar wind the southat trade wind coming from the south that was deflected to the left. But less land is present in the southern hemisphere to obstruct the path The prevailing air currents also affect the distribution of different ecosystems. At the equator for example, the hot air gives up moisture, rises and undergoes adiabatic changes ancl the resulting rainfall supports luxuriant forests. The drier air descends at about 30" latitude, therefore, major desert regions of the earth like Sahara, and American south-west and the Thar desert in India are formed in this belt. The air again becomes warm, picks up moisture and ascends at 60" latitudes and then travels polewards. Almost no rainfall accompanies its descent in the planar regions.