基于GRACE卫星测量得到的中国及其周边地区陆地水量变化

Land Water Storage Variations in China and Adjacent Areas Revealed by the GRACE Gravity Mission

GRACE卫星成功开辟了空间大地测量对地观测的新途径。利用GRACE卫星得到的时变地球重力资料,分析估计了中国及其周边地区陆地水量的变化趋势,较为清晰地揭示了该地区季节性变化特征。进一步采用13点滑动平均的方法扣除了季节性变化,提取了4个特征区域(喜马拉雅南部,新疆与西藏及其周边的亚洲高山区域,中国华北、东北地区和中国南部地区)的陆地水量变化特征信息,这4个区域陆地水量的变化趋势分别为-12.7±0.7、-60.4±2.7、-12.5±0.5和6.6±0.9km3/a。其中:喜马拉雅南部和亚洲高山区域陆地水量呈现明显的衰减趋势,与Matsuo和Heki模拟冰川质量损失源得到的结果较为一致;但近10年来亚洲高山区域西北部冰川加速融化趋势并不明显。中国华北、东北地区和南部地区水量变化比较复杂,具不稳定的变化趋势。

The success of GRACE has blazed a new trail in the Earth observation on space geodesy.Based on the time-varying gravity anomaly data of the GRACE mission,long-term variations of continental water storage in China and its adjacent areas were estimated.Seasonal changes of water storage in China and its adjacent regions have been clearly revealed.With the remove of seasonal changes by 13-points moving averages,the long-term change rates of continental water storage in four distinct zones,namely southern Himalaya,Asian high mountains of the Xinjiang Uygur Autonomous Region plus Tibet and its neighbourhood,Northern China,and Southern China,were found to be-12.7±0.7 km3/a,-60.4±2.7 km3/a,-12.5±0.5 km3/a and ＋6.6±0.9 km3/a,respectively.Continental water storages of southern Himalaya and the Asian high mountains show apparent decreasing trends,which are consistent with the results of Matsuo and Heki by substantial glacial ice melting in these Asian high mountains.However,acceleration of mass loss of high mountain glaciers in the Northwestern Asian is not clear in recent decades.The long-term trends of continental water storage in the northeast and south of the North China are not stable.