Abstract. Lakes are important sources of freshwater and provide
essential ecosystem services. Monitoring their spatial and temporal
variability, and their functions, is an important task within the
development of sustainable water management strategies. The Surface Water
and Ocean Topography (SWOT) mission will provide continuous information on
the dynamics of continental (rivers, lakes, wetlands and reservoirs) and
ocean water bodies. This work aims to contribute to the international effort evaluating the SWOT satellite (2022 launch) performance for water balance assessment over large lakes (e.g., >100 km2). For this purpose, a hydrodynamic model was set up over Mamawi Lake, Canada, and different wind scenarios on lake hydrodynamics were simulated. The derived water surface elevations (WSEs) were compared to synthetic elevations produced by the Jet Propulsion Laboratory (JPL) SWOT high resolution (SWOT-HR) simulator. Moreover, water storages and net flows were retrieved from different possible SWOT orbital configurations and synthetic
gauge measurements. In general, a good agreement was found between the WSE
simulated from the model and those mimicked by the SWOT-HR simulator.
Depending on the wind scenario, errors ranged between approximately −2 and 5 cm for mean error and from 30 to 70 cm root mean square error. Low spatial coverage of the lake was found to generate important biases in the
retrievals of water volume or net flow between two satellite passes in the
presence of local heterogeneities in WSE. However, the precision of
retrievals was found to increase as spatial coverage increases, becoming
more reliable than the retrievals from three synthetic gauges when spatial
coverage approaches 100 %, demonstrating the capabilities of the future
SWOT mission in monitoring dynamic WSE for large lakes across Canada.
Anticipated Improvements to River Surface Elevation Profiles From the Surface Water and Ocean Topography Mission
