On the effect of non-tidal atmospheric loading on altimetry orbits
Event: 2018 Ocean Surface Topography Science Team Meeting
Session: Precision Orbit Determination
Presentation type: Type Oral
The German Research Centre for Geosciences GFZ provides non-tidal atmospheric loading displacements for tracking stations located on the Earth’s surface based on the ERA Interim atmospheric reanalysis from ECMWF and compatible with GRACE atmosphere and ocean de-aliasing products (AOD1B) that model the gravity effect. We apply both, the geometrical and the dynamical effect, to Precise Orbit Determination (POD) of the altimetry missions TOPEX, JASON-1, JASON-2, and ENVISAT with Satellite Laser Ranging (SLR) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) observations. For comparison we exchange the GFZ displacements with those provided by the International Mass Loading Service (IMLS) based on the MERRA weather model. The differences in orbit restitution are qualified in terms of orbital fits and orbit differences. In particular the impact of the non-tidal atmospheric loading on the regional and the global mean sea level is assessed with special focus on seasonal to decadal time scales.