ABSTRACT
Precipitation formation and distribution are largely controlled by two factors: the availability of atmospheric moisture, and the presence of upward vertical motion. Warmer air can hold more moisture than colder air, which often means tropical areas have more precipitation than colder regions, although this is not always true. Continental interiors usually have less precipitation than nearby coastal areas, also due to less available atmospheric moisture. It is estimated that only 15% of globally evaporated water each year comes from continental areas, with the remainder from the world’s oceans.[1] Locations with predominant rising air, such as the forced lifting over mountain areas, usually have more precipitation than nearby lower elevations. There are clear exceptions to these general patterns, however, which result from a sometimes complicating set of factors.
