Current status of the planned GFZ RL07 GRACE/GRACE-FO Level-2 time series

As part of the Science Data System, the GFZ Helmholtz Centre for Geosciences is one of the official GRACE/GRACE-FO Level-2 processing centers which routinely provide monthly gravity field models. These models are used by a wide range of geoscientists to infer mass changes at the Earth’s surface to study climate-related phenomena. Currently, GFZ´s operationally processed monthly gravity fields are still based on release 6 (RL06) standards. The distribution of a reprocessed and improved RL07 time series is planned for fall 2025. Most of the improvements have been developed within the Research Unit “New Refined Observations of Climate Change from Spaceborne Gravity Missions” (NEROGRAV) funded by the German Research Foundation DFG.

The main focus of the new release is on optimized stochastic modeling during the Level-2 processing. This includes the extension of the stochastic instrument error models, the optimization of the combination of the different observations, and the inclusion of tidal and temporally changing non-tidal background model error variance-covariance matrices in the adjustment process.

We present an overview of the expected performance of our upcoming RL07 gravity field time series compared to the current RL06 time series. Improvements stemming from the applied advanced processing strategy become visible in terms of a reduced noise level, as well as more realistic formal errors.