TUD-L2B-EWH_UNC-GRACE: Global 0.5°x0.5° monthly equivalent water height user-friendly dataset with comprehensive uncertainty decomposition (Solution disparity, AOD1B uncertainty, DDK leakage error, and GIA ensemble error)

This dataset provides gridded Equivalent Water Height (EWH), which are equivalent on land to Terrestrial Water Storage Anomalies (TWSA) from GRACE and GRACE-FO generated at TU Delft (“TUD”), filtered using the DDK{i} (i=2,...,7) decorrelation filter (Kusche et al., 2009) on a 0.5° × 0.5° global grid. Each file contains monthly fields from 2002–2020. All weighted mean and uncertainty components include gravity signal content from degree 2 to 60. Weights are computed as the normalised square inverses of open-ocean RMS using COST-G RL02.1 (Meyer, U. et al., 2025) monthly solutions as a benchmark. Coefficients C20 and C30 are already replaced using TN-14v3 (https://doi.org/10.1029/2019GL085488). The user can add the geocenter motion (TN-13) contribution (degree-1) separately, as well as remove prominent tidal components (S2, P1, S1, K1, and unmodelled R3), which can be found in the ancillary product TUD-L2B-EWH_CLIM-GRACE.

The novelty in this product is the consolidation of multiple official GRACE Level-2 spherical harmonic solutions and their uncertainty propagation into a single multi-component uncertainty budget, which includes:

(1) the GIA trend (Bagge, M. et al. 2023),

(2) AOD1B (based on AOe07) (Shihora, L. et al. 2024),

(3) solution disparity (includes effects of parametrisation, and ocean tide models),

(4) filtering leakage (Dobslaw, H. et al. 2020), with finally

(5) degree-1 uncertainty (Swenson, S., D. Chambers, and J. Wahr, 2008).


This layered GRACE(-FO) Level-2B data product provides a comprehensive and transparent view of all uncertainty and post-processing components (including the TUD-L2B-EWH_CLIM-GRACE product), enabling direct application in data assimilation strategies or other applications.


Details on the data product structure and use can be found at the TUDelft GRACEcube portal:

https://grace-cube.lr.tudelft.nl/L2B_UNC/README.html