ABSTRACT

The regional scale mass change provides a substantial understanding to the influence of climate change on the glacier surface. However, the scarce ground observations and large spatial extent limit the use of field-based mass balance estimation. In this study, the Gravity Recovery and Climate Experiment (GRACE) satellite data were used to estimate the regional glacier mass variation over the Karakoram and Himalayas (KH) region during 2002–2019 hydrological years. Our study showed that the total mass change rate over the KH region was – 55.0 ± 8.7 Gt yr^–1 for the study period. We have identified four positive/negative clusters of mass change over the KH region, with the eastern part of the Karakoram (KK) and part of the Central Himalaya (CH) regions have experienced a positive mass change. In contrast, the junctio n area between the Western Himalaya (WH) and CH region observed an extreme negative mass change. The results demonstrated that the annual mass change for WH become negative or nearly zero from 2007/08 onwards, while for CH and Eastern Himalaya (EH) regions, it became negative since 2005/06. The GRACE-derived mass change was validated with the published in-situ mass balance data, which reveals a high correlation (r = 0.77) over the region. The performance of obtained results were also compared with Ice, Cloud, and Land Elevation Satellite-1 (ICESat-1) data for the period 2003–2009, indicating a correlation of 0.87 and 0.91 for monthly and annual scale, respectively. Moreover, the interannual mass change in the glaciated region was analyzed using hydro-climatic data and energy fluxes, suggesting a higher correlation of mass change with total precipitation and snowfall over the spatiotemporal scale. However, this correlation fails at locations where evaporation, runoff, and radiation have prominently influenced the mass loss. The uncertainty and sensitivity test for mass change demonstrated that snowfall and temperature have a strong influence on the response of mass change. Overall, this study provided regional mass change and their relationship with hydro-climatic variables, which will provide a better understanding related to the water availability in the downstream areas.

摘要

区域尺度的质量变化为气候变化对冰川表面的影响提供了实质性的理解。然而，稀少的地面观测和大的空间范围限制了基于现场的质量平衡估计的使用。在这项研究中，重力恢复和气候实验 (GRACE) 卫星数据用于估计 2002-2019 水文年期间喀喇昆仑山和喜马拉雅山 (KH) 地区的区域冰川质量变化。我们的研究表明，KH 区域的总质量变化率为 – 55.0 ± 8.7 Gt yr ^–1在学习期间。我们已经在 KH 地区确定了四个正/负质量变化簇，喀喇昆仑山脉东部 (KK) 和喜马拉雅中部 (CH) 地区的部分地区经历了正质量变化。相比之下，西喜马拉雅 (WH) 和 CH 区域之间的连接区域观察到极端的负质量变化。结果表明，从 2007/08 年开始，WH 的年质量变化变为负值或接近于零，而对于 CH 和东喜马拉雅 (EH) 地区，自 2005/06 年开始变为负值。GRACE 衍生的质量变化已通过已发布的原位质量平衡数据，揭示了该地区的高度相关性 (r = 0.77)。还将获得的结果的性能与 2003-2009 年期间的冰、云和陆地高程卫星 1 (ICESat-1) 数据进行了比较，表明月度和年度尺度的相关性分别为 0.87 和 0.91。此外，利用水文气候数据和能量通量分析了冰川地区的年际质量变化，表明质量变化与时空尺度上的总降水量和降雪量具有更高的相关性。然而，这种相关性在蒸发、径流和辐射显着影响质量损失的位置失败。质量变化的不确定性和敏感性测试表明，降雪和温度对质量变化的响应有很强的影响。总体，