NASA Image courtesy JPL Imaging Radar . In temperate regions, most precipitation in winter is as snow. In higher elevations, some snow may last through the summer months. The melting of this snow may provide water for irrigation and hydroelectric power. Satellite observations of snow cover aid in predicting how much water will be available during the drier summer months in some areas.
Snow is shown in white and sea ice is dark blue.
Image data obtained from National Snow and Ice Data Center web site ,University of Colorado, Boulder, June,1998. Animation created at Center for Earth and Planetary Studies. The water of the hydrosphere is in constant motion. Water evaporates from both the land and seas. The water vapor in the atmosphere condenses to form clouds and falls as rain or snow.