Mass-related excitation of polar motion: an assessment of the new RL06 GRACE gravity field models
Mass-related excitation of polar motion: an assessment of the new RL06 GRACE gravity field models
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DOI：
10.1186/s40623-018-0968-4
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发表时间：
2018-12-12
影响因子：
3
通讯作者：
Seitz, Florian
中科院分区：
文献类型：
--
作者：
Goettl, Franziska;Schmidt, Michael;Seitz, Florian
通过将新的Release-06（RL 06）重力恢复和气候实验（GRACE）重力场解转换为极移的赤道有效角动量函数（所谓的激发函数）并将其与基于空间大地测量观测（大地测量激发）的相应时间序列进行比较，对这些解进行了评估。使用相同的处理对较旧的RL 05溶液进行相同的处理。从这两个版本中得到的等效水高图显示，在RL 06中，信噪比得到了显著改善。从RL 05和RL 06导出的极移激励函数相差约15%。不同地球子系统的贡献的分析表明，释放更新主要影响水文（12%）和海洋激发（17%），但它有一个相对较小的影响有关南极洲（4%）和格陵兰岛（1%）的冰冻圈激发。来自不同GRACE处理中心的RL 06数据比以前的RL 05数据更加一致。基于GRACE的激发函数与大地测量和基于模型的海洋激发函数的比较表明，最新发布的更新将一致性提高了约2至15个百分点。
The new Release-06 (RL06) Gravity Recovery and Climate Experiment (GRACE) gravity field solutions are evaluated by converting them into equatorial effective angular momentum functions (so-called excitation functions) for polar motion and comparing these to respective time series based on space-geodetic observations (geodetic excitation). The same is performed for the older RL05 solutions using identical processing. Maps of equivalent water heights derived from both releases show that the signal-to-noise ratio is significantly improved in RL06. The derived polar motion excitation functions from RL05 and RL06 differ by about 15%. An analysis of the contributions of different Earth subsystems revealed that the release update mainly influenced the hydrological (12%) and oceanic excitations (17%), but it has a relatively small impact on the cryospheric excitations related to Antarctica (4%) and Greenland (1%). The RL06 data from different GRACE processing centers are more consistent among each other than the previous RL05 data. Comparisons of the GRACE-based excitation functions with the geodetic and model-based oceanic excitations show that the latest release update improved the agreement by about 2 to 15 percentage points.