Comprehensive coastal circulation model with application to the Gulf of Maine

TLDR

The study presents a state‑of‑the‑art finite element ocean model and demonstrates its application to the Gulf of Maine. The model is a 3‑D hydrostatic, fully nonlinear finite element system with advanced turbulence closure, tidal‑time resolution, and unstructured meshes enabling variable horizontal and vertical resolution, forced climatologically for March–April and July–August. Simulations reproduce a cyclonic central Gulf circulation, a coastal current with multiple branch points, anticyclonic flow around Georges Bank, seasonal modulation, surface circulation consistent with drift observations, and depth structure shaped by basin topography and baroclinicity.

Abstract

A state-of-the-art finite element model is described and applications are shown for the Gulf of Maine. The model is three-dimensional (hydrostatic) with a free surface, fully nonlinear, incorporates advanced turbulence closure and operates in tidal time. Variable horizontal and vertical resolution are facilitated by the use of unstructured meshes. Solutions for the Gulf of Maine illustrate performance in the context of several isolated nonlinear processes. Composite solutions for March–April and July–August time periods are recorded under climatological forcing. The solutions exhibit a general cyclonic central Gulf circulation, a coastal current with several branch points and anticyclonic circulation around Georges Bank. Each of these features is seasonally modulated. The surface circulation is in general agreement with surface drift observations. The circulation at depth shows the combined influence of deep basin topography and baroclinicity.