This federal grant was awarded by the National Aeronautics and Space Administration (NASA) Shared Services Center to the University of Washington (UW) to conduct an in-depth study of (sub)mesoscale ocean variability. The overarching goal is to better characterize surface density variability, particularly the role of salinity, across the submesoscale to mesoscale range. The $649,021 grant will leverage satellite observations, such as sea surface temperature and ocean color, along with in situ measurements of salinity, temperature, optical properties, and velocity to quantify the structure and kinematic properties of salinity and density fronts in the California Current Front and Gulf Stream/North Atlantic Drift Front regions. This work aims to improve understanding of submesoscale/mesoscale interactions in areas where salinity drives density variability on these scales, supporting NASA's Ocean Surface Salinity and Temperature (OSST) program objectives.