Spatial sensitivity of the Gravity Recovery and Climate Experiment (GRACE) time‐variable gravity observations
Spatial sensitivity of the Gravity Recovery and Climate Experiment (GRACE) time‐variable gravity observations
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DOI：
10.1029/2004jb003536
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发表时间：
2005-08
影响因子：
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通讯作者：
Jianli Chen;C. Wilson;J. Famiglietti;M. Rodell
中科院分区：
文献类型：
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作者：
Jianli Chen;C. Wilson;J. Famiglietti;M. Rodell
我们分析了由重力恢复和气候实验（GRACE）双卫星使命观测的时变重力确定的陆地水储存和大地水准面高度变化的空间敏感性。根据2002年4月至2003年12月期间GRACE卫星的15个月重力解，我们研究了半径从400到2000公里变化的空间平滑效应，并得出结论，800公里的高斯平滑半径对GRACE是有效的。推导出陆地水储量，并在GRACE结果和估计的水储量变化之间的差异的陆地上产生最小RMS残差全球陆地数据同化系统。对于GRACE估计的大地水准面高度变化，有效平滑半径可以下降到600 km。当年度（例如，的正弦和余弦）分量是主要关注的，GRACE估计的陆地水存储或大地水准面高度变化的有效空间分辨率可分别达到600和400 km。
We analyze the spatial sensitivities of terrestrial water storage and geoid height changes determined from the time-variable gravity observed by the Gravity Recovery and Climate Experiment (GRACE) twin satellite mission. On the basis of 15 GRACE monthly gravity solutions, covering the period April 2002 to December 2003, we examine the effects of spatial smoothing at radii varying from 400 to 2000 km and conclude that a 800 km Gaussian smoothing radius is effective for GRACE-derived terrestrial water storage and produces the minimum RMS residuals over the land of the differences between GRACE results and estimated water storage change from a global land data assimilation system. For GRACE estimated geoid height change, the effective smoothing radius can go down to 600 km. When the annual (e.g., the sine and cosine) components are the primary concern, the effective spatial resolution can reach 600 and 400 km for GRACE estimated terrestrial water storage or geoid height change, respectively.