Jinbo Wang (Texas A&M University, United States); Bruce Haines (Jet Propulsion Laboratory, California Institute of Technology, United States ); Andy Wu (Jet Propulsion Laboratory, California Institute of Technology, United States); Scott Stalin (NOAA PMEL, United States)

SWOT’s unprecedented two-dimensional interferometric measurements offer new opportunities to observe variability in ocean surface wave conditions. We evaluate SWOT’s significant wave height (SWH) product via comparison to an array of in situ wave measurements off Central California during SWOT’s Cal/Val orbit and find that SWOT SWH measurements resolve wave conditions with high fidelity (CC>0.99, RMSE<0.2 m), performance consistent in additional comparison to a network of coastal wave buoys. SWOT accurately resolves gradients over short spatial scales (20-70 km). These wave height gradients can arise from interactions with mesoscale and submesoscale ocean currents. We identify SWH gradients associated with strong Western Boundary Currents and characterize the intermittency in these gradients related to both the background circulation and incident wave conditions. Consistent with previous numerical modeling work, SWOT observes amplification of SWH over the Gulf Stream as high as 2 meters when waves propagate from the northwest. The sensitivity to incident wave direction leads to seasonality in wave-current interactions tied to the Atlantic wave climate. Overall, these findings demonstrate the use of SWOT’s wide-swath observations as a powerful tool for observing and understanding ocean surface wave conditions and their connection to both ocean circulation, atmospheric variability, and regional wave climatology.