Global Geography of Submesoscale Density Fronts

Caitlin B Whalen, Applied Physics Laboratory University of Washington, Seattle, WA, United States, Kyla Drushka, University of Washington, Applied Physics Laboratory, Seattle, WA, United States and Peter Gaube, Applied Physics Laboratory at the University of Washington, Air-Sea Interaction and Remote Sensing, Seattle, WA, United States
Ocean fronts on submesoscales (0.1 - 10s km) host a range of turbulent processes that are of first-order importance to local physical dynamics, chemistry, and biology in the surface mixed layer and stratified water below. Previous observational and modeling studies suggest that these submesoscale frontal processes, such as mixed layer baroclinic instability, may be significant on regional and global scales. Here we use historical ship thermosalinograph data co-located with satellite-derived sea surface temperature measurements and reanalysis winds to map the global geography and impact of submesoscale fronts. We find that the magnitude and prevalence of submesoscale density fronts vary significantly on a global scale. The estimated equivalent heat flux due to mixed layer baroclinic instabilities and Ekman effects also vary regionally throughout the world’s oceans.