Woods Hole Coastal and Marine Science Center


next up previous contents
Next: Vertical Mixing Up: Model Implementation Previous: Numerical Scheme

Model Geometry and Bathymetry

The model was configured on a 68 x 68 horizontal curvilinear orthogonal grid (Figure 2.1).

  Model grid for the three-dimensional circulation model of Massachusetts 
and Cape Cod Bays
Figure 2.1: Model grid for the three-dimensional circulation model of Massachusetts and Cape Cod Bays. The curvilinear orthogonal grid allows the mesh resolution to vary spatially, having a minimum grid spacing of 600 m and a maximum spacing of 6000 m. The grid spacing in the vicinity of the future outfall is roughly 1000 m. The 40 m isobath is represented by the thick grey line.

The grid spacing ranges from approximately 600 m in Boston Harbor to about 6000 m along the open boundary with the Gulf of Maine. The grid spacing in the vicinity of the future outfall site is approximately 1000 m. The grid extends well offshore of Massachusetts Bay to allow exchange with the Gulf of Maine inside the model domain, and extends far enough north to include the Merrimack River, a large source of fresh water to the region. Initially 10 evenly spaced sigma levels were used in the vertical dimension, but final runs utilized 2 additional near-surface layers at 1 and 4% of the water depth to better resolve river plumes and the surface mixed layer.

The bathymetry for the model was obtained by interpolating NOAA sounding data on to the model grid using an inverse distance method. The resulting grid was Shapiro filtered (Shapiro, 1975) to remove 2 grid length variability, and a maximum depth of 140 m was set to eliminate the deep complex topography offshore of Massachusetts Bay. The minimum depth was set to 3 m to avoid flooding and drying.


next up previous contents
Next: Vertical Mixing Up: Model Implementation Previous: Numerical Scheme

Skip Navigation

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USAGov logo U.S. Department of the Interior | U.S. Geological Survey

URL: woodshole.er.usgs.gov/operations/modeling/mbayopen/node11.html
Page Contact Information: WHSC Webmaster
This page last modified on Monday, 24-Nov-2014 13:04:14 EST