Description: Five types of ice in the climate system are discussed. Sea ice forms when ocean water reaches its freezing temperature of about -2°C. Sea ice is currently found in the Arctic Ocean and around Antarctica. Ice sheets form on land and are composed of compacted snow that has accumulated over time. Ice sheets spread over a land surface and can reach the ocean. If the ice continuity is maintained when the ice sheet reaches the ocean, the ice will float on the water and this is referred to as an ice shelf. Icebergs are large chunks of glaciers that break off into the ocean. They can become grounded in shallow water, but generally are moved by the wind and ocean currents. Mountain glaciers form on mountains and are typically found at high latitudes, but also occur near the equator at sufficiently high elevation.