Separating GIA signal from surface mass change using GPS and GRACE data
Separating GIA signal from surface mass change using GPS and GRACE data
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使用 GPS 和 GRACE 数据将 GIA 信号与表面质量变化分离
DOI：
10.1093/gji/ggac336
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发表时间：
2022
影响因子：
2.8
通讯作者：
S. Royston
中科院分区：
文献类型：
--
作者：
B. Vishwakarma;Y. Ziegler;J. Bamber;S. Royston
全球导航卫星系统（GNSS）和卫星重力测量等大地测量系统可以检测固体地球对过去冰川周期和当今表面质量变化（PDSMC）的粘弹性响应。当代 PDSMC 大部分是由气候变化驱动的，为了利用上述大地测量更好地理解它们，应首先考虑冰川均衡调整（GIA）信号。默认方法是使用正向 GIA 模型，该模型使用不确定的冰荷载历史和近似地球流变学来预测 GIA，从而产生很大的不确定性。因此，当代全球大地测量观测及其覆盖范围的激增使得数据驱动的 GIA 解决方案的估算成为可能。提出了一种新颖的框架，利用垂直陆地运动 (VLM) 与 GIA 和 PDSMC 引起的位势异常之间的地球物理关系，将 GPS VLM 趋势和 GRACE 位势趋势表示为 GIA 或 PDSMC 的函数，可以使用最小二乘回归轻松解决。 GIA 的估计是数据驱动的，与阿拉斯加和格陵兰岛的预测模型有很大不同。
The visco-elastic response of the solid Earth to the past glacial cycles and the present day surface mass change (PDSMC) are detected by the geodetic observation systems such as global navigation satellite system (GNSS) and satellite gravimetry. Majority of the contemporary PDSMC is driven by climate change and in order to better understand them using the aforementioned geodetic observations, glacial isostatic adjustment (GIA) signal should be accounted first. The default approach is to use forward GIA models that use uncertain ice-load history and approximate Earth rheology to predict GIA, yielding large uncertainties. The proliferation of contemporary, global, geodetic observations and their coverage have therefore enabled estimation of data-driven GIA solutions. A novel framework is presented that uses geophysical relations between the vertical land motion (VLM) and geopotential anomaly due to GIA and PDSMC to express GPS VLM trends and GRACE geopotential trends as a function of either GIA or PDSMC, which can be easily solved using least-squares regression. The GIA estimates are data-driven and differ significantly from forward models over Alaska and Greenland.