Long-term altimetry data is one of the important data sources to analyze the change of global ice reserves. This study focuses on the elevation and volume changes of Greenland Ice Sheet during 2010-2019 derived from altimetry observations. For better results, the methods for determining surface elevation change rates are discussed and specific strategies are designed. A new elevation-difference method is proposed for the slope terrains at the margins of the ice sheet where CryoSat-2 provides interferometric synthetic aperture (SARin) observations is proved to be effective through the validation with Airborne Topographic Mapper (ATM) data. Meanwhile, a Surface-fit method is applied for the flat interior of ice sheet where the low resolution mode (LRM) observations are provided. The results of elevation change rates of Greenland Ice Sheet during 2010 to 2019 are eventually calculated by combining CryoSat-2 and ATM observations. An elevation change rate of -11.83±1.14 cm·a-1 is revealed, corresponding to a volume change rate of -200.22±18.26 km3·a-1. The results are compared with the elevation changes determined by ICESat during 2003 to 2009. Our results show that the overall volume change rate of Greenland Ice Sheet had an approximately 10% slowdown during the past decade and the areas with the most serious ice and snow loss have shifted from the southeast coast to the west margin of the ice sheet.

中文翻译：

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根据测高仪数据得出的2010-2019年格陵兰冰盖的海拔和体积变化

长期测高数据是分析全球冰储量变化的重要数据来源之一。这项研究的重点是从高空观测获得的2010-2019年格陵兰冰盖的海拔和体积变化。为了获得更好的结果，讨论了确定表面高程变化率的方法并设计了特定的策略。针对冰盖边缘的斜坡地形，提出了一种新的高程差异方法，其中CryoSat-2提供了干涉合成孔径（SARin）观测结果，通过机载地形测绘仪（ATM）数据的验证证明是有效的。同时，将Surface-fit方法应用于具有低分辨率模式（LRM）观测值的冰盖的平坦内部。通过结合CryoSat-2和ATM观测结果，最终计算出了2010年至2019年格陵兰冰原的海拔变化率结果。显示出-11.83±1.14 cm·a-1的高程变化率，对应于-200.22±18.26 km3·a-1的体积变化率。将结果与ICESat在2003年至2009年期间确定的海拔变化进行了比较。我们的结果表明，格陵兰冰原的总体体积变化率在过去十年中以及冰雪损失最严重的地区下降了约10％。已经从东南沿海转移到冰原的西边缘。