Ice and snow: The water cycle

Arctic perennial sea ice has been decreasing at a rate of 9% per decade, with the most significant loss appearing in the past three years. This animation, derived from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSMI), shows the annual minimum sea ice extent and concentration for 25 years, from 1979 to 2004. The year 2002 showed the lowest level of sea ice on record, with 2003 and 2004 not far behind.