Circulation, dispersion and hydrodynamic connectivity over the Scotian Shelf and adjacent waters

Abstract

A nested-grid ocean circulation modelling system is used in this study to examine the circulation of surfacewaters over the Scotian Shelf and its adjacent coastal water bodies. The modelling system consists of acoarse-resolution (1/12°) barotropic storm surge (outer) model covering the northwest Atlantic Ocean, and afine-resolution (1/16°) baroclinic (inner) model covering the Gulf of St. Lawrence, Scotian Shelf, and Gulf of Maine.The three-dimensional model currents are used to track trajectories of particles using a Lagrangian particle-trackingmodel. The simulated particle movements and distributions are used to examine the dispersion, retention, andhydrodynamic connectivity of surface waters over the study region. The near-surface dispersion is relatively high overwestern Cabot Strait, the inner Scotian Shelf, and the shelf break of the Scotian Shelf. The dispersion is relatively low inNorthumberland Strait. A process study is conducted to examine the physical processes affecting the surface dispersion,including tidal forcing and local wind forcing. The model results show that the tidal currents significantly influence thedispersion of surface waters in the Bay of Fundy.