Yeosang Yoon (NASA Goddard Space Flight Center, USA); Elyssa Collins (NASA Goddard Space Flight Center, USA); Sujay Kumar (NASA Goddard Space Flight Center, USA)

Optimally integrating the measurements from the Surface Water and Ocean Topography (SWOT) satellite into hydrological models has been a challenge that the scientific community has been working on way before the satellite was launched. Many attempts using synthetic data have been presented in the literature, and most of them focus on SWOT discharge data assimilation (DA). In order to avoid known high errors in discharge data, we adopt a slight different approach where water surface elevation (WSE) is assimilated instead. This approach comes with other challenges. Here, we summarize and discuss the challenges and opportunities in integrating SWOT WSE into NASA’s Land Information System (LIS). We focus on NASA Goddard’s efforts related to (1) riverbed elevation tunning, (2) data assimilation and representation of human impacts on surface waters. We provide particular insights and preliminary results on addressing the elevation bias between satellite measurements and models, which is an existing limitation when assimilating SWOT WSE. We tackle that issue with a methodology to fit global riverbed elevations to SWOT measurements, which substantially reduces bias between datasets. We anticipate that the these efforts, in combination with synergetic NASA on multivariate DA, will provide an improved representation of the global terrestrial water storage variability and fluxes, and anthropogenic impacts.