TUD-L2B-EWH_UNC-GRACEv4: Global 0.5°x0.5° monthly equivalent water height user-friendly dataset with comprehensive uncertainty decomposition (ensemble solution spread, AOD1B uncertainty, DDK leakage error, low-degree coefficient treatment, 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 and TUD-L2B-EWH_CLIM_CORR-GRACE.<br>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) ensemble solution spread (uncertainty), previously referred to as "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).<br>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 and TUD-L2B-EWH_CLIM_LEAKAGE-GRACE product), enabling direct application in data assimilation strategies or other applications. For v3 (onwards) we provide the SLR-free dataset (TUD-L2B-EWH_UNC_noSLR-GRACE) for users who wish to perform sensitivity studies. Lastly, for v4 we additionally provide the fully application-ready "ewh_mean_corr" (GIA, SLR, degree-1, and tidal aliasing corrected for) variable in the main data product, and the CLIM_CORR associated data product. <br>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<br>Versioning:v4:(1) Added fully post-processed (GIA, SLR, degree-1, tidal aliasing removed) EWH called "ewh_mean_corr".(2) Added reconstructed geophysical climatological signal "ewh_mean_clim" in CLIM data products.(3) Added reconstructed tidal aliasing climatological signal "ewh_mean_tides" in CLIM data products.(4) Added CLIM_CORR data product containing full, tidal and residual climatological signals as CLIM. <br>v3:(1) Provided "noSLR" ancillary product for sensitivity analysis.(2) Provided uncertainties from post-fit residuals for climatological products. (3) Period span (i.e. 2002 - 2020) is added directly into the file name convention.<br>v2.0:(1) leakage uncertainty computed using standard deviation (instead of RMS) to have it harmonised with the ensemble mean.(2) "v2.0" added to the name of the data product.(3) the addition of the "residuals" and "t_clim" variables to the ancillary TUD-L2B-EWH_CLIM-GRACEv2.0 product for improved user-friendliness.(4) added leakage climatological ancillary data product: TUD-L2B-EWH_CLIM_LEAKAGE-GRACEv2.0,(5) added propagated uncertainties from replaced SLR C20 and C30 (formal errors),(6) improved README file.<br>v1.0: original dataset.