Arnaud Cerbelaud (Jet Propulsion Laboratory, California Institute of Technology, United States); Cedric H. David (Jet Propulsion Laboratory, California Institute of Technology, United States); George H. Allen (Department of Geosciences, Virginia Tech, United States)

Flow waves are long river waves driven by rising discharge from rainfall, snowmelt, or reservoir operations. With its dense spatial sampling of global river water surface elevations, the Surface Water and Ocean Topography (SWOT) satellite is uniquely positioned to capture flow waves as they propagate downstream. Complementing the hydrologic time series collected by gauges, SWOT records “space series" that can show detailed variations in river heights over downstream distance during a flow wave. Through previous research, we identified several examples of flow waves recorded by both SWOT and gauges and showed how SWOT observations could be used to estimate flow wave properties. Here, we build upon this effort to record and analyze flow waves at a larger scale. We develop a tool to automate and expand the flow wave detection process, gathering a dataset of the peak flow events SWOT has observed within the Mississippi River basin during its lifetime. We also estimate multiple properties of these flow wave events, such as their spatial extents, amplitudes, and celerities. In the future, our tool could be applied beyond the Mississippi basin to detect flow waves anywhere on Earth, supporting global-scale studies. Collectively, results from this work can inform assessments of river water storages and flows, improve river routing model parameter estimates, support flood control and reservoir operations, and help refine sampling requirements for future satellite missions.