Freshening Along the US East Coast by Hurricane Dorian Captured by the SMOS Satellite

Hurricane Dorian made landfall on the Abaco Islands’ coast on September 1, 2019, as a Category 5 hurricane, tying the record for maximum winds at landfall for an Atlantic hurricane. The storm then moved north along the US East Coast, causing catastrophic damage from winds, rainfall, and storm surge from Florida to the Carolinas. The storm made a second landfall on Cape Hatteras as a Category 1 hurricane on September 6. Dorian continued to move north as an extratropical storm, impacting Nova Scotia on September 8 before finally dissipating near Greenland on September 10. This study uses satellite estimates of Sea Surface Salinity (SSS) to document a freshening of the Atlantic surface coastal waters associated with the passage of Dorian. European Space Agency’s Soil Moisture, Ocean Salinity (SMOS) satellite’s SSS fields are used to investigate the salinity anomalies following Dorian. The SSS satellite observations are plotted from late August to mid-September to capture spatial patterns of salinity before, during, and after the storm’s passage. The remote sensing observations are compared to available direct observations of surface salinity. The effects of rainfall, coastal stream flow, and changes in salinity advection due to the impact of Dorian in the Gulf Stream transport are considered in order to interpret the observed freshening.