Document Type



Virginia Institute of Marine Science

VIMS Department/Program

Center for Coastal Resources Management (CCRM)

Publication Date



Journal of Geophysical Research: Oceans





First Page



A 3D unstructured-grid ocean circulation model covering the continental shelf and coastal seas around New England is used to investigate freshwater transport (FWT) on the Scotian Shelf (SS) and its impact on the salinity in the Gulf of Maine (GoME). The model was first validated using observed elevation, velocity, temperature, and salinity at multiple locations, demonstrating generally high model skills. Intraseasonal variabilities of freshwater fluxes in 2017 and 2018 were then analyzed across different transects around SS and Browns Bank (BB). These indicated that the flow pattern in SS during 2017 was consistent with previous understanding: low salinity water flows southwestward along the shelf and turns into the GoME around BB. However, in 2018, most of the low salinity water did not enter the GoME, but was transported to the open ocean. The most striking difference occurred early in the year when the FWT, normally at its maximum, was practically stopped by an anticyclonic eddy impinging upon the shelf break near the western end of SS. Then in March, in contrast to the prevailing eastward wind, two southwestward wind events occurred that induced an excessive amount of FWT in SS. We further showed that when anticyclonic eddies impinge on the shelf break, the typical geostrophic balance associated with southwestward flow is interrupted, and a new geostrophic balance is established with the directions of pressure gradient force and flow reversed. The influence from anticyclonic eddies explains the abnormally low FWT in SS and higher GoME salinity in 2018


doi: 10.1029/2021JC017663

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© 2022. American Geophysical Union.

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