TUD-L3-EWH_UNC-GRACE: A Global Level‑3 GRACE(-FO) EWH Uncertainty Product

Michal Cuadrat-Grzybowski , Pieter N. A. M. VIsser, Joao G. Teixeira da Encarnacao

We present TUD-L3-EWH\_UNC-GRACE, a globally gridded Level-3 GRACE(-FO) equivalent water height (EWH) data product providing an extensive characterisation of uncertainty for direct use in Earth system research. Unlike conventional approaches that either require propagation of full normal matrices or rely on empirical assumptions regarding temporal and spatial correlations, the dataset combines ensemble statistics from independently processed Level-2 solutions to quantify uncertainties associated with ocean tide models, parametrisation strategies, and Atmosphere and Ocean De-aliasing products. Post-processing uncertainties related to filtering effects and Glacial Isostatic Adjustment (GIA) model variability are quantified using a known-pair approach and an ensemble of 56 GIA models, respectively. Uncertainty fields are provided for multiple anisotropic filtering strategies (DDK2--DDK7), enabling assessment of filtering strength, leakage effects, and processing-choice impacts on total uncertainty. In addition to the standard Level-2/3 configuration, the ancillary TUD-L3-EWH\_UNC\_noSLR-GRACE product, in which low-degree coefficients ($C_{2,0}$ and $C_{3,0}$) are not replaced by Satellite Laser Ranging estimates, allows users to isolate uncertainties associated with low-degree coefficient treatment. TUD-L3-EWH\_UNC is the first Level-3 EWH dataset to provide end-to-end gridded uncertainty fields, supporting applications in hydrology, glaciology, solid-Earth, and oceanographic studies. Ancillary tidal corrections and climatological fits are distributed separately through the TUD-L3-EWH\_CLIM-GRACE product suite. The dataset is available at DOI: 10.4121/4fc748e8-01c7-4f06-87da-653937b078f7.