The Drought Events over the Amazon River Basin from 2003 to 2020 Detected by GRACE/GRACE-FO and Swarm Satellites

The climate anomaly in the Amazon River basin (ARB) has a very important influence on global change and always been focus of scientists from all over world. To fill 11-month data gap between Gravity Recovery Climate Experiment (GRACE) GRACE Follow-On (GRACE-FO) missions, we fused TWSC results six solutions by using generalized three-cornered hat least square method to improve reliability results, then combined Swarm construct an uninterrupted long time series TWSC-based drought index (GRACE/Swarm-DSI). was used detect characterize events ARB 2003 2020. show that GRACE/Swarm-DSI strong correlation with Self-Calibrating Palmer Drought Severity Index (SCPDSI) (0.6345), Standardized Precipitation Evapotranspiration Index-3 (SPEI-3) (0.5411), SPEI-6 (0.6377) SPEI-12 (0.6820), Nash–Sutcliffe efficiency above four indices are 0.3348, 0.2786, 0.4044 0.4627, respectively. Eleven were identified during study period, 2005, 2010 2016 droughts most severe longest. precipitation (PPT) (the coefficient is 0.55 2-month delay) higher than evapotranspiration (ET) ?0.18 12-month delay). It explains less PPT main cause ARB. greater plains one mountains response 1~2 months regions. Our provide certain reference for hydrological application model filling GRACE-FO missions.