利用卫星影像进行南极格罗夫山蓝冰变化监测
Satellite Monitoring of Blue-Ice Extent in Grove Mountains,Antarctica
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摘要: 利用MODIS及Landsat的系列影像数据,监测东南极格罗夫山的蓝冰变化。首先,使用MODIS原始数据进行蓝冰提取与范围统计,总结了蓝冰年度内的变化规律:蓝冰面积在9~12月间有上升趋势,直到第二年的1月中旬至下旬达到面积最大值,2~4月面积重新减小。然后,对Landsat影像使用监督分类结合目视判别的方法提取蓝冰地物。通过蓝冰边缘线的比较,得出蓝冰范围有东移趋势的结论。最后,揭示了短波辐射与气候变化对蓝冰范围变化的影响。Abstract: The series images of moderate resolution imaging spectroradiomete(MODIS) and Landsat are used to track seasonal and interannual variations of blue-ice extent in the Grove Mountains on East Antarctica.We introduce the process of using MODIS mapping algorithm to separate and calculate the blue-ice,and summarize the variation regularity of annual blue-ice exposure.The area grows rapidly from September to December,and peaks by the middle or late of next January.Then,it declines from February to April.We also analyze the images of Landsat sensors,and separate the blue-ice by supervised classification combined with the sight modification.According to the comparison of the edge lines of blue-ice,we find that the blue-ice extent has the eastward trend.And the sensitivity of blue-ice areas related to the changes of climate and shortwave radicalization is also revealed.