摘要
高亚洲地区是中纬度全球变化敏感区和研究的热点区域,其境内湖泊星罗棋布,湖冰冻融参数是全球变化的关键敏感因子之一。由于冰水介电常数差异大,高重访率且对天气不敏感的星载被动微波遥感可实现湖冰冻融状态的快速监测。本数据集依据微波辐射计像元内湖泊和陆表的面积比例,应用混合像元分解方法获取了像元(亚像元级)的湖泊亮温信息,实现高亚洲地区被动微波遥感亚像元级湖冰冻融监测,并采用多种被动微波数据,共计获得高亚洲区域2002~2016年51个中大型时间序列湖泊亮温数据和冻融状态信息。以无云MODIS光学产品为验证数据,在高亚洲不同区域,选取可可西里湖、达则错、库赛湖等三个大小不一的湖泊进行冻融判别验证,结果表明微波和光学遥感所获取的湖冰冻结和融化参数具有较高的一致性,其相关系数可达0.968与0.987。本数据集包含湖泊的时间序列亮温值和湖冰冻融参数,可进一步对湖泊开展特征参数反演,以及提升对高亚洲地区的湖冰冻融的理解,为高亚洲地区气候、环境变化以及高亚洲对全球气候变化响应模型提供数据基础。
High Asia is a region dotted with lakes,sensitive to changes that are occurring in the mid-latitudes of the northern hemisphere.It is thus a focus for researchers.Due to widely different dielectric constants of ice and water,satellite passive microwave remote sensing,which has a high revisit rate and is insensitive to the weather,can be used for quick detection of the thawing and freezing of lake ice.Based on the proportions of lake and land areas within the microwave radiometer pixels,the brightness temperature of a lake surface was acquired by linear and dynamic decomposition of the radiometer footprint measurements.The freezing and thawing of 51 sub-pixel level lakes in the High Asia region was closely monitored during the period 2002–2016.The data obtained there were then validated against the cloud-free MODIS optical snow product data.The validation test selected three lakes with different sizes located in different parts of High Asia-Hoh Xil Lake,Dagze Co and Kusai Lake.Results suggest that the freezing and thawing times are highly correlated with each other and have correlation coefficients of 0.968 and 0.987,as measured by the optical and microwave remote sensing approach,respectively.The polished dataset contains lake brightness temperatures and lake ice freeze-thaw in different basins of High Asia.These data can be used to carry out inversion of geophysical parameters of other lakes and to enhance the understanding of lake freezing and thawing in High Asia,thus providing a data base of climate and environmental change in High Asia and also of this region’s response to global climate change.
作者
邱玉宝
郭华东
阮永俭
付心如
石利娟
田邦森
Qiu Yubao;Guo Huadong;Ruan Yongjian;Fu Xinru;Shi Lijuan;Tian Bangsen
基金
中国科学院国际合作局对外合作重点项目(131Cll KYSB20160061)
国家自然科学基金(41371351)
国家自然科学基金重点项目(ABCC计划,41120114001).
关键词
高亚洲
湖泊
被动微波亮温
冻融参数
混合像元分解法
High Asia
lake
passive microwave brightness temperature
freeze-thaw parameters
Pixel Unmixing method
