Hydrological Information in Rapid, 21-day Quick-Look GRACE-FO Solutions

Abstract:

As part of an initial data quality assessment for the Gravity Recover and Climate Experiment Follow-On (GRACE-FO) satellite mission, the Center for Space Research (CSR) produces daily sliding window (quick-look or QL) gravity field estimates. Besides the different input Level 1 data (quick-look versus final from JPL), these solutions differ from the definitive CSR monthly solutions both in the applied filter (21-day CRN vs ~30-day boxcar) and atmospheric and oceanographic model used to reduce high-frequency aliasing. Given the reduced product latency of the QL solutions over the definitive solutions (12 days vs ~6 weeks from the temporal center of the solution to availability), we examine the hydrological information in the QL solutions to understand the utility in scientific applications. We find that these solutions provide reliable indications of the tendencies of terrestrial water storage (TWS) on large spatial scales. We illustrate the differences in the variability of the QL and definitive solutions for basin averaged TWS estimates, which is an important for interpreting the results.