Evaluation of globally gridded precipitation data and satellite-based terrestrial water storage products using hydrological drought recovery time

Abstract. Accurate precipitation observations are crucial for understanding meteorological and hydrological processes. Most precipitation products rely on station-based observations, either directly or for bias-corrected satellite retrievals. To validate these station-based precipitation products, additional independent data sources are necessary. This study aims to assess the performance of the Global Precipitation Climatology Centre (GPCC) Full Data Monthly Product v2022 and Global Precipitation Climatology Project (GPCP) v3.2 Monthly Analysis Product by estimating the hydrological drought recovery time (DRT) from precipitation and the terrestrial water storage anomaly (TWSA) acquired from satellite gravimetry. This study also evaluates the drought monitoring performance of G3P and JPL mascon total water storage (TWS) monthly solutions from the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) satellite missions. The current study employed two methods to estimate DRT and evaluated the consistency of DRT estimates by calculating the time difference in DRT values derived from the two methods. Globally and across all climate zones, GPCC and GPCP showed comparable performance in hydrological applications with no significant differences in the mean DRT estimates. For the TWS products, DRT estimates using JPL mascon were, on average, 2.6 months longer than those using G3P. However, G3P showed approximately 5.0 % higher consistency than JPL mascon globally and across each climate zone, suggesting its better suitability for more precise drought-related analyses. These findings indicate that G3P outperforms JPL mascon in aligning with precipitation products and offers better consistency in DRT estimation. These results provide valuable insights into the accuracy of precipitation and TWSA products by utilizing hydrological drought characteristics, enhancing our understanding of meteorological and hydrological processes.