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Puget Sound Georgia Basin Model

Hydrodynamic Model Framework

The Salish Sea Model (SSM) covering the Puget Sound and Georgia Basins was developed using the Finite Volume Coastal Ocean Model (FVCOM) framework (an open source code released by UMASSD-WHOI; Chen et al., 2003). The hydrodynamic component of SSM provides year-long simulations of water-surface elevations, currents, salinity, and temperature, driven by hourly tides, daily freshwater inflows, and meteorological forcing. Tides propagate into the domain from the west through the Strait of Juan De Fuca and move north into Georgia Strait past San Juan Islands and into Puget Sound through Admiralty Inlet. More information about river inflows and meteorological inputs to the model is provided under individual tabs.

Salish Sea Model Grid

SSM model grid with 16,012 nodes and 25,019 triangular elements. The vertical configuration of the model uses 10 sigma-stretched layers distributed using a power law function with an exponent P-Sigma of 1.5, which provides more layer density near the surface.

For efficient year-long simulations, we have developed an intermediate-scale version of the entire domain with grid size varying from 100-350 m in estuaries and bays to as large as 800-3000 in the main basins, expanding to 3 km in the Northwest Straits to about 12 km over the continental shelf. It uses an unstructured grid with triangular elements and is well suited to accommodate complex shoreline geometry, waterways, and islands within this domain.

This scale allows sufficient resolution of the various major river estuaries and sub-basins while allowing year-long simulations within 12 hours of run time on a multiprocessor cluster computer (see Khangaonkar et al. 2017a; Khangaonkar et al. 2018). A sigma-stretched coordinate system is used in the vertical plane with 10 terrain-following sigma layers with higher layer-density near the surface. A fine-scale version with cells sides as small as 10 m is also available (see Khangaonkar and Yang 2011; Yang and Khangaonkar 2010).

Salish Sea Model Overview

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