Study On The Variation Of Arctic Sea Ice Extent And Snow Depth On Sea Ice Using Satellite Remote Sensing Data

Arctic is the most sensitive area in the earth, sea ice in arctic has been changingrapidly in recent years. Arctic sea ice extent in summer in arctic is decreasingsignificantly. The global climate is impacted by the change of sea ice. The insulatingeffect of snow reduces the heat transfer between ice and atmosphere. The analysis ofthe snow variation will provide further knowledge on the reasons of the rapid changesof Arctic sea ice.In this paper, the variation of Arctic sea ice extent during2003to2010isanalyzed. The variation of snow depth with time and latitude, as well as the influenceof ice ridges on snow depth and albedo are investigated.Arctic sea ice extent is derived from sea ice concentration by Aqua/AMSR-E(The Advanced Microwave Scanning Radiometer for EOS) data, sea ice extent during2003to2010is analyzed. The results show the minimum sea ice extent in2007.Arctic sea ice in summer is declining. The reasons for the rapid declines are theinternal change of sea ice and the external change due to the environment.The variation of the snow depth over Arctic sea ice is analyzed using the datafrom AMSR-E. Due to the pentration depth of37and19GHz, the upper limit forsnow depth retrieval is50cm in max.Two types of the snow depth data based on seaice concentration from ASI and NT2ice concentration algorithms respectively, arecompared. The results of the comparisons during the period of2008to2010show thatthe two products are consistent in the area covered mainly by first-year ice in theChukchi Sea, with the relatively bias of8.7%. The error is due to the difference of seaice concentration. The weekly averaged snow depth data with sea ice concentrationfrom ASI algorithm are used to investigate the variation of the snow depth over Arcticsea ice. The snow depth on first-year ice changes with seasons, on October first-yearsea ice just frost the snow depth is about10cm when the first-year ice formed, and20cm to30cm by the end of Arctic winter,and more than40cm in some rough surface. Sea ice ridges distribute mainly on multi-year ice region, but a small amount ofridges also exist on the relatively rough first-year ice region. The images fromLandsat/ETM+(Enhanced Thematic Mapper Plus) and Aqua/MODIS(Moderate-resolution Imaging Spectroradiometer) are used to get the ridges.Compared with albedo retrieved from NOAA/AVHRR (National Oceanic andAtmospheric Administration/Advanced Very High Resolution Radiometer)data andsnow depth from AMSR-E, the influences of sea ice ridges on albedo and snow depthare analyzed. The results show that the albedo and snow depth are reletively higher inridge area than smooth area.