Non‐Tidal Background Modeling for Satellite Gravimetry Based on Operational ECWMF and ERA5 Reanalysis Data: AOD1B RL07

• Published in: Journal of Geophysical Research: Solid Earth
• Main Authors: Shihora, Linus, Balidakis, Kyriakos, Dill, Robert, Dahle, Christoph, Ghobadi‐Far, Khosro, Bonin, Jennifer, Dobslaw, Henryk, Balidakis, Kyriakos; 1 GFZ German Research Centre for Geosciences Potsdam Germany, Dill, Robert; 1 GFZ German Research Centre for Geosciences Potsdam Germany, Dahle, Christoph; 1 GFZ German Research Centre for Geosciences Potsdam Germany, Ghobadi‐Far, Khosro; 2 Department of Geosciences Virginia Tech Blacksburg VA USA, Bonin, Jennifer; 3 University of South Florida St. Petersburg FL USA, Dobslaw, Henryk; 1 GFZ German Research Centre for Geosciences Potsdam Germany
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: ddc:526.7; AOD1B RL07; GRACE; ERA5; self‐attraction and loading; satellite gravimetry; Antarc*; Antarctica; Ice Shelves
• Online Access: https://doi.org/10.1029/2022JB024360; http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10409

The Atmosphere and Ocean De‐Aliasing Level‐1B (AOD1B) product provides a priori information about temporal variations in the Earth's gravity field induced by non‐tidal circulation processes in atmosphere and ocean. It is routinely applied as a background model in the Gravity Recovery and Climate Experiment (GRACE)/GRACE Follow‐On (GRACE‐FO) satellite gravimetry data processing. We here present three new datasets in preparation for the upcoming release RL07 of AOD1B, that are based on either the global ERA5 reanalysis or the ECMWF operational data together with simulations from the Max‐Planck‐Institute for Meteorology general circulation model forced consistently with the fields of the same atmospheric data set. The oceanic simulations newly include an updated bathymetry around Antarctica including cavities under the ice shelves, the explicit implementation of the feedback effects of self‐attraction and loading to ocean dynamics as well as a refined harmonic tidal analysis. Comparison to the current release of AOD1B in terms of GRACE‐FO K‐band range‐acceleration pre‐fit residuals, LRI line‐of‐sight gravity differences and band‐pass filtered altimetry data reveals an overall improvement in the representation of the high‐frequency mass variability. Potential benefits of enhancing the temporal resolution remain inconclusive so that the upcoming release 07 will be sampled again every 3 hr. Plain Language Summary: Satellite gravimetry missions such as the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow‐On (GRACE‐FO), which play a vital role in the monitoring of the Earth's mass transports, require a priori background information on the high‐frequency mass variations which can not be resolved by the monthly gravity solutions. The Atmosphere and Ocean De‐Aliasing Level‐1B (AOD1B) data product provides the required background information for non‐tidal high‐frequency mass changes in the atmosphere and oceans. However, the accurate representation of these mass variations remains challenging and ...