利用MODIS产品数据研究分析南极海岸带雪盖面积变化

本文利用MODIS雪产品数据研究分析了2003-2006年南极大陆海岸带雪盖面积的总体变化规律,并在此基础上选取18个典型区作进一步研究,分析了其局地特征。研究表明,南极大陆海岸带地区积雪覆盖面积总体上呈波动下降趋势,暖季比寒季波动显著。从积雪时间变化看:季节尺度上,南极海岸带地区寒季(4-10月)雪盖面积迅速增加,暖季(11-3月)雪盖面积的变化趋势表现不一致,2004年和2006年表现为先减少后增加,2005年为先增加后减少,但总体呈现减少的趋势,寒暖两季雪盖面积变化的特征与气候因素呈正反馈;年际尺度上,2003年的雪盖面积高于其他年份,2004年锐减之后再缓慢增加,总体上显现出波动伴随下降的趋势。从积雪空间上看,雪盖变化主要集中在南极大陆海岸线一带,大陆腹地的变化很小,可以忽略。另外,西南极雪盖变化比东南极显著。

MONITORING SNOW-COVER AREA CHANGE IN ANTARCTIC COASTLINE REGION BY USING MODIS PRODUCT DATA

Based on MODIS snow products,we studied the changes of snow cover area during 2003—2006 in Antarctic coastline region,and on the basis of that,we selected 18 typical regions for further analysis.The result showed that the change of snow cover area was in a fluctuant downward trend on a whole,and was more marked in warm season than in cold season.In temporal scale:for the season cycle,the snow cover extent increased rapidly in cold season(April—October),while the performance in warm season(November—March)was not exactly the same during the four years.In warm season,the snow cover extent decreased at first and then increased in the year of 2004 and 2006,however,increased firstly and then decreased in 2005,but reduced on the whole,which was a positive feedback.For the interannual cycle,snow cover extent was the biggest in 2003,but reached the lowest level in 2004,and then increased gradually during 2005—2006,whereas,it reduced on the whole.In spatial scale,along the coastline region of Antarctic continent is the mainly changed area,meanwhile,the change is more obvious in West Antarctica than in East Antarctica.