Using Swarm to Detect Total Water Storage Changes in 26 Global Basins (Taking the Amazon Basin, Volga Basin and Zambezi Basin as Examples)

The Gravity Recovery and Climate Experiment (GRACE) satellite provides time-varying gravity field models that can detect total water storage change (TWSC) from April 2002 to June 2017, its second-generation satellite, GRACE Follow-On (GRACE-FO), 2018, so there is a one year gap. Swarm satellites are equipped with Global Positioning System (GPS) receivers, which be used recover the Earth’s gravitational field. Swarm’s (from December 2013 2018) were solved by International Combination Service for Time-variable Field Solutions (COST-G) Astronomical Institute of Czech Academy Sciences (ASI). On timely scale, has potential fill gap between two generations satellites. In this paper, using 26 global watersheds as study area, first, we explored optimal data processing strategy then obtained Swarm-TWSC each watershed based on results. Second, evaluated accuracy in detecting regional variations, analyzed reasons superior inferior performance different regions, systematically terrestrial changes land areas. Finally, constructed time series 2019 combining GRACE, Swarm, GRACE-FO Amazon, Volga, Zambezi Basins. results show GRACE. worldwide; related area size, runoff volume, annual mass change, instantaneous itself, among latter main factor affecting Swarm-TWSC. Knowledge basins paper important long-term basins.