Towards AOD1B RL07

The Atmosphere and Ocean non-tidal De-aliasing Level-1B (AOD1B) product is widely used internationally to correct for transient effects of atmosphere-ocean mass variability on Earth satellites at in particular low altitudes. The most recent release 06 is given every 3 hours in Stokes coefficients expanded up to degree and order 180. It is based on ERA-Interim and ECMWF operational data for the atmosphere, and simulations with the global general ocean circulation model MPIOM consistently forced with fields from the same atmospheric data-set. RL06 was introduced in the year 2016 and is routinely updated every 24 hours with all data-sets for the previous calendar day.

Based on a stationary error assessment for AOD1B RL06 that might be also used to explicitly characterize uncertainties of AOD1B in the gravity field estimation process, we present preliminary numerical experiments with the TP10 configuration of MPIOM in preparation of a new AOD1B version 07 which is planned to be released in the year 2021. Those experiments test effects of (i) the new hourly atmospheric forcing data-set from the latest reanalysis ERA-5 of ECMWF; (ii) a revised bathymetry in particular around Antarctica that also includes cavities underneath the ice-shelves; and the consideration of shielding effects of the ice cover; and (iii) the consequences of self-attraction and loading feedbacks on the ocean dynamics. Results will be discussed in terms of differences with respect to RL06, in situ ocean observations, and alternative model data-sets.