Abstract: The Laptev Sea is an important marginal sea and ice source region which has a significant influence on sea ice coverage in the Arctic Ocean. Multi-year variations of sea ice in Laptev Sea within ten years (2002—2011) are studied by analyzing the AMSR-E sea ice concentration data also the NECP-DOE wind and temperature data. During the ten years, sea ice in the Laptev Sea underwent a course from heavy ice year to light ice year. There was a good relation between ice condition and the ice melting duration, which shows that the longer the duration was, the lighter the ice condition was. Four parameters, including indices of sea ice anomaly, minimum ratio of sea ice coverage, accumulated temperature and wind indices, are defined to describe the multi-year variations of sea ice in the Laptev Sea. Indices of sea ice anomaly are time-averaged (from March to November) value of sea ice coverage ratio, which quantitatively express ice condition. Minimum ratio of sea ice coverage shows the extreme condition of sea ice in summertime, which usually occurred between late August and early October with a magnitude among 0.45%~48.73%. Accumulated temperature, which represents the last wintertime impact of atmospheric temperature, is the prime factor influencing the ice condition of current year. The heavy ice year of 2008 resulted from the strongly low temperature of last wintertime. Wind indices represent the short-term impact to sea ice coverage in Laptev Sea from wind forcing. In contrast to the same period of other years, anomaly of northerly wind appeared in April 2006 and September 2007, which to some extent gave rise to postponing the onset of ice melting in 2006 and to positive anomaly of sea ice coverage in summer, 2007.

Key words: Arctic, Laptev Sea, Sea Ice Coverage Ratio, Multi-Year Variation, Remote Sensing