Updating the ESA Earth System Model for Future Gravity Missions Simulation Studies

The ESA Earth System Model (ESA ESM) provides a synthetic data-set of the time-variable global gravity field that includes realistic mass variations in atmosphere, oceans, terrestrial water storage, continental ice-sheets, and the solid Earth on a wide set of spatial and temporal frequencies. It was widely applied as a source model in simulations of for gravity missions, but has been also applied to study novel gravity observing concepts on the ground. For that purpose, the ESM needs to include a wide range of signals even at very small spatial scales which might not yet have been reliably observed by any active mission.

In this contribution, we present first steps towards an update to the current ESA ESM. We focus in particular on an evolved oceanic component which will newly include (a) deep oceanic transport variations in the Atlantic Overturning Circulation and the associated variation in oceanic bottom pressure along the shelf slope of the Western boundary; (b) an update to the realistically perturbed de-aliasing model and (c) the inclusion of the Sea-Level Equation for spatially variable barystatic sea-level variations and global mass conservation.