1) The portion of the earth which consists of the ice masses and snow deposits which include continental ice sheets, mountainous glaciers, sea ice, surface snow cover and lake/river ice. Alterations in the extent of snow cover are due to seasonal fluctuations and are interrelated with atmospheric circulation. Sea level and hydrologic cycle variations can affect the volume of water tied up in the glaciers and ice sheets.
source: [Canadian Geographer; v36; 336-350; 1992.] [Canadian Geographer; v37; 86-87; 1993.]