JPL GRACE and GRACE-FO Mascon Ocean, Ice, and Hydrology Equivalent Water Height Coastal Resolution Improvement (CRI) Filtered Release 06.3 Version 04

This dataset contains gridded monthly global water storage/height anomalies relative to a time-mean, derived from GRACE and GRACE-FO and processed at JPL using the Mascon approach (RL06.3Mv04). A Coastal Resolution Improvement (CRI) filter has been applied to this data set to reduce signal leakage errors across coastlines. For most land hydrology, oceanographic as well as land-ice applications this is the recommend data set for the analysis of surface mass changes. The data are provided in a single data file in netCDF format, with water storage/height anomalies in equivalent water thickness units (cm). The data are derived from solving for monthly gravity field variations on geolocated spherical cap mass concentration functions, rather than global spherical harmonic coefficients. Additionally, realistic geophysical information is introduced during the computation to intrinsically remove correlated errors. Thus, these Mascon grids do not need to be de-correlated or smoothed, like traditional spherical harmonic gravity solutions.
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The complete Mascon solution consists of 4,551 independent estimates of surface mass change that have been derived using an equal-area 3-degree grid of individual mascons. A subset of these individual mascons span coastlines, and contain mixed land and ocean mass change signals. In a post-processing step, the CRI filter is applied to those mixed land/ocean Mascons to separate land and ocean mass. The land mask used to perform this separation is provided in the same directory as this dataset, as are uncertainty values, and the gridded mascon-ID number to enable further analysis. Since the individual mascons act as an inherent smoother on the gravity field, a set of optional gain factors (for continental hydrology applications) that can be applied to the solution to study mass change signals at sub-mascon resolution is also provided within the same data directory as the Mascon data. For use-case examples and further background on the gain factors, please see Wiese, Landerer & Watkins, 2016, https://doi.org/10.1002/2016WR019344.
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This RL06.3Mv04 is an updated version of the previous Tellus JPL Mascon RL06.1Mv03 (DOI, 10.5067/TEMSC-3JC63). For a detailed description on the Mascon solution, including the mathematical derivation, implementation of geophysical constraints, and solution validation, please see Watkins et al., 2015, doi: 10.1002/2014JB011547. For a detailed description of the CRI filter implementation, please see Wiese et al., 2016, doi:10.1002/2016WR019344.

本数据集包含了基于GRACE和GRACE-FO测量的全球月度水储/高度异常数据，相对于时间平均值，经喷气推进实验室（JPL）采用Mascon方法（RL06.3Mv04）处理而成。为降低沿海地区的信号泄露误差，已对此数据集应用了沿海分辨率改进（CRI）滤波器。对于大多数陆地水文、海洋学以及陆地冰应用，该数据集是分析地表质量变化的首选。数据以netCDF格式提供，包含以等效水厚度单位（厘米）表示的水储/高度异常。数据是通过求解位于球形帽质量浓度函数上的月度重力场变化而得出的，而非全球球谐系数。此外，在计算过程中引入了现实主义的地球物理信息，以内在地消除相关误差。因此，这些Mascon网格无需像传统的球谐重力解那样进行去相关或平滑处理。

完整的Mascon解决方案包括4,551个独立的表面质量变化估计值，这些估计值是使用等面积3度网格的单独mascon进行推导的。其中一部分mascon横跨海岸线，并包含混合的陆地和海洋质量变化信号。在后续处理步骤中，对那些混合的陆地/海洋Mascon应用CRI滤波器，以分离陆地和海洋质量。用于此分离的陆地掩码、不确定值以及网格化的mascon-ID编号均提供在同一目录中，以便进行进一步分析。由于单个mascon在重力场中充当内在的平滑器，因此还提供了可选的增益因子（适用于大陆水文应用），这些因子可应用于解决方案中，以研究亚mascon分辨率的质变化信号。有关用例示例和增益因子的进一步背景信息，请参阅Wiese, Landerer & Watkins, 2016，https://doi.org/10.1002/2016WR019344。

RL06.3Mv04是之前Tellus JPL Mascon RL06.1Mv03（DOI，10.5067/TEMSC-3JC63）的更新版本。关于Mascon解决方案的详细描述，包括数学推导、地球物理约束的实施和解决方案验证，请参阅Watkins et al., 2015，doi: 10.1002/2014JB011547。有关CRI滤波器实现的详细描述，请参阅Wiese et al., 2016，doi: 10.1002/2016WR019344。