In geodesy, a key application of data from the Gravity Recovery and Climate Experiment (GRACE), GRACE Follow-On (GRACE-FO), and Satellite Laser Ranging (SLR) is an interpretation of changes in polar motion excitation due to variations in the Earth’s surficial fluids, especially in the continental water, snow, and ice. Such impacts are usually examined by computing hydrological and cryospheric polar motion excitation (hydrological and cryospheric angular momentum, HAM/CAM). Three types of GRACE and GRACE-FO data can be used to determine HAM/CAM, namely degree-2 order-1 spherical harmonic coefficients of geopotential, gridded terrestrial water storage anomalies computed from spherical harmonic coefficients, and terrestrial water storage anomalies obtained from mascon solutions. This study compares HAM/CAM computed from these three kinds of gravimetric data. A comparison of GRACE-based excitation series with HAM/CAM obtained from SLR is also provided. A validation of different HAM/CAM estimates is conducted here using the so-called geodetic residual time series (GAO), which describes the hydrological and cryospheric signal in the observed polar motion excitation. Our analysis of GRACE mission data indicates that the use of mascon solutions provides higher consistency between HAM/CAM and GAO than the use of other datasets, especially in the seasonal spectral band. These conclusions are confirmed by the results obtained for data from first 2 years of GRACE-FO. Overall, after 2 years from the start of GRACE-FO, the high consistency between HAM/CAM and GAO that was achieved during the best GRACE period has not yet been repeated. However, it should be remembered that with the systematic appearance of subsequent GRACE-FO observations, this quality can be expected to increase. SLR data can be used for determination of HAM/CAM to fill the one-year-long data gap between the end of GRACE and the start of the GRACE-FO mission. In addition, SLR series could be particularly useful in determination of HAM/CAM in the non-seasonal spectral band. Despite its low seasonal amplitudes, SLR-based HAM/CAM provides high phase consistency with GAO for annual and semiannual oscillation.

在大地测量学中，重力恢复和气候实验（GRACE），GRACE后续跟踪（GRACE-FO）和卫星激光测距（SLR）数据的关键应用是对由于极化变化引起的极运动激发变化的解释。地球的地表流体，特别是在大陆的水，雪和冰中。通常通过计算水文和冰冻圈极运动激发（水文和冰冻圈角动量，HAM / CAM）来检查这种影响。可以使用三种类型的GRACE和GRACE-FO数据来确定HAM / CAM，即地势的2度1阶球谐系数，根据球谐系数计算的网格化地面储水异常以及从mascon获得的地面储水异常解决方案。这项研究比较了从这三种重量数据计算得出的HAM / CAM。还提供了基于GRACE的激励序列与从SLR获得的HAM / CAM的比较。在这里使用所谓的大地残余时间序列（GAO）对不同的HAM / CAM估计值进行验证，该序列描述了观测到的极运动激发中的水文和冰冻圈信号。我们对GRACE任务数据的分析表明，与其他数据集相比，使用mascon解决方案在HAM / CAM和GAO之间提供更高的一致性，尤其是在季节性光谱带中。这些结论被GRACE-FO的前两年数据所获得的结果所证实。总体而言，自GRACE-FO成立2年后，在最佳GRACE期间达到的HAM / CAM和GAO之间的高度一致性尚未重现。但是，应该记住，随着随后的GRACE-FO观测的系统出现，这种质量有望提高。SLR数据可用于确定HAM / CAM，以填补GRACE结束与GRACE-FO任务开始之间长达一年的数据空白。此外，SLR系列对于确定非季节性光谱带中的HAM / CAM可能特别有用。尽管季节性振幅低，基于SLR的HAM / CAM仍可与GAO保持高相位一致性，以实现年度和半年度振荡。SLR数据可用于确定HAM / CAM，以填补GRACE结束与GRACE-FO任务开始之间长达一年的数据空白。此外，SLR系列对于确定非季节性光谱带中的HAM / CAM可能特别有用。尽管季节性振幅低，基于SLR的HAM / CAM仍可与GAO保持高相位一致性，以实现年度和半年度振荡。SLR数据可用于确定HAM / CAM，以填补GRACE结束与GRACE-FO任务开始之间长达一年的数据空白。此外，SLR系列对于确定非季节性光谱带中的HAM / CAM可能特别有用。尽管季节性振幅低，基于SLR的HAM / CAM仍可与GAO保持高相位一致性，以实现年度和半年度振荡。