On June 21 st the sun s rays shine perpendicular upon the Tropic of Cancer. The same thing happens at the Tropic of Capricorn on September 21 st . This angle marks the southernmost point at which the sun can be seen in the Northern hemisphere, and the northernmost point at which the midnight sun can be seen in South polar regions. Circulation of Atmosphere Air circulates through the atmosphere in cold and warm fronts. With the help of these fronts, precipitation reaches areas far away from water masses.
Orographic precipitation occurs when air rises due to the influence of mountains.
Moisture bearing air is forced to rise over mountain ranges, where the air cools, and the moisture condenses into rainfall. This kind of rainfall is most common where wind blows moist air over the ocean on to the land and up the side of a coastal mountain range. Winds are caused by pressure differences. A breeze is explained by the fact that air tends to move from areas of high pressure to areas of low pressure. Winds tend to blow into the land from oceans during summer and to the ocean from the land during winter.