Evaluation of new GRACE time-variable gravity data over the ocean
Evaluation of new GRACE time-variable gravity data over the ocean
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DOI：
10.1029/2006gl027296
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发表时间：
2006-09-08
影响因子：
5.2
通讯作者：
Chambers, Don P.
中科院分区：
文献类型：
--
作者：
Chambers, Don P.
利用2003年2月至2005年4月期间的GRACE卫星重力场模型，分析了全球三大科学处理中心（CSR、GFZ和JPL）的重力场资料。这些数据用于估计平滑半径为500公里和750公里的海平面质量分量图。除了使用新的重力场模型外，还应用了一个滤波器来估计和消除系数中的系统误差，这些误差会导致等效水位图中的错误模式。过滤器的描述和它的效果进行了讨论。GRACE地图已被评估使用残差分析与高度计海平面从Jason-1的空间变化校正使用世界海洋地图集2001年每月气候图。根据所有3个处理中心的平均数据确定的GRACE地图的平均不确定性估计在750公里平滑处小于1.8厘米RMS，在500公里平滑处小于2.4厘米RMS，这比以前使用第一代GRACE重力场发现的要好。
Monthly GRACE gravity field models from the three science processing centers (CSR, GFZ, and JPL) are analyzed for the period from February 2003 to April 2005 over the ocean. The data are used to estimate maps of the mass component of sea level at smoothing radii of 500 km and 750 km. In addition to using new gravity field models, a filter has been applied to estimate and remove systematic errors in the coefficients that cause erroneous patterns in the maps of equivalent water level. The filter is described and its effects are discussed. The GRACE maps have been evaluated using a residual analysis with maps of altimeter sea level from Jason-1 corrected for steric variations using the World Ocean Atlas 2001 monthly climatology. The mean uncertainty of GRACE maps determined from an average of data from all 3 processing centers is estimated to be less than 1.8 cm RMS at 750 km smoothing and 2.4 cm at 500 km smoothing, which is better than was found previously using the first generation GRACE gravity fields.