Shifts in water-level variation of Namco in the central Tibetan Plateau from ICESat and Cryo Sat-2 altimetry and station observations  

作　　者：Chunqiao Song Qinghua Ye Xiao Cheng 

机构地区：[1]Institute of Tibetan Plateau Research (ITP), Chinese Academy of Sciences [2]Department of Geography, University of California [3]State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University

出　　处：《Science Bulletin》2015年第14期1287-1297,共11页科学通报（英文版）

基　　金：supported by the National Special Basic Research Project of the Ministry of Science and Technology(2013FY111400-2,2009CB723901);the National Natural Science Foundation of China(41120114001,41125003,41071254,40971048);the European Space Agency(ESA AO 2605);the Knowledge Innovation Foundation Program for outstanding Young Scholar of Chinese Academy of Sciences(CAS)(KZCX2-EWQN104);supported by Open Research Fund of Key Laboratory of Tibetan Environmental Changes and Land Surface Processes in Chinese Academy of Sciences;Open Fund of State Key Laboratory of Remote Sensing Science

摘　　要：The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The CryoSat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003-2009. In this study, the comparison of CryoSat-2 altimetry for Namco with in situ water-level data suggests a high cor- relation coefficient of 0.71 （P 〈 0.01）, with the mean error of -0.12 m and root-mean-square error of 0.18 m. Further, the combination of ICESat and CryoSat-2 altimetry data and in situ lake-level observations reveals a rapid water- level rise of 0.24 4- 0.04 m/year during 2003-2008 and then a slightly decreasing trend of -0.09 4- 0.04 m/year during 2009-2013. This study suggests that the CryoSat-2 altimetry has the potential of sustaining the fine observa- tions on Tibetan lakes, following the ICESat mission. Besides, the examination of four key climatic variables （temperature, precipitation, potential evapotranspiration, and relative humidity） during 1990-2013 indicates that the wetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth.The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The Cryo Sat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003–2009.In this study, the comparison of Cryo Sat-2 altimetry for Namco with in situ water-level data suggests a high correlation coefficient of 0.71(P \ 0.01), with the mean error of-0.12 m and root-mean-square error of 0.18 m. Further,the combination of ICESat and Cryo Sat-2 altimetry data and in situ lake-level observations reveals a rapid waterlevel rise of 0.24 ± 0.04 m/year during 2003–2008 and then a slightly decreasing trend of-0.09 ± 0.04 m/year during 2009–2013. This study suggests that the Cryo Sat-2altimetry has the potential of sustaining the fine observations on Tibetan lakes, following the ICESat mission.Besides, the examination of four key climatic variables(temperature, precipitation, potential evapotranspiration,and relative humidity) during 1990–2013 indicates that thewetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth.

关 键 词：LAKE Satellite altimetry CryoSat-2ICESat Tibetan Plateau - Climate change 

分 类 号：P228.3[天文地球—大地测量学与测量工程] P332.3[天文地球—测绘科学与技术]