Finally, mountains provide shade . For a more detailed description of glacier flow, mass budgets, and albedo, check out Glacial Systems in our hypertext. For a glacier to form, a sufficient amount of precipitation must fall in the form of snow and be preserved. This map displays one major control on the spatial distribution of glaciers. The greatest precipitation is in the equatorial regions.
Higher elevations defy the normal latitudinal variations in precipitation due to orographic uplift .
The heavy local precipitation typical of some mountainous regions cannot be shown at the scale of this figure. Orographic Uplift Orographic Uplift occurs in where a moist maritime air mass encounters a mountain front. The air mass is then forced to rise. Areas that are located far inland from large water bodies have less precipitation because much of the moisture in the atmosphere has already been dropped on intervening mountainous regions. At a given latitude, the elevation at which glaciers occur rises inland.