Initial and Boundary Conditions

Gulf of Mexico Hybrid Coordinate Ocean Model (GoM-HYCOM) Initial and Boundary Conditions for Shelf and Coastal Models

Several coastal and shelf models are nested within the GoM-HYCOM domain: NGoM-HYCOM, WFS-HYCOM, SoFLA-HYCOM, using fields for initial and boundary conditions (one-way nesting). The nesting technique follows the standard and robust capability for the nesting of HYCOM model domains, by employing boundary conditions that implement archived variables (off-line) from the coarse outer grid to the fine inner grid. The barotropic boundary conditions along the nested interface use the method of characteristics. The baroclinic fields for temperature, salinity, pressure and velocity in the nested model are relaxed toward the outer model solution within buffer zones and over e-folding times that are usually dictated by the archive frequency.

Example of smooth transition from the outer GoM-HYCOM model (left) to the nested SoFLA-HYCOM model (right). The fields are Sea Surface Height instantaneous fields for 00Z on June 30, 2004 (upper), May 29, 2004 (middle) and September 26, 2004 (bottom). The SoFLA domain is marked on the GoM plots as a red rectangular.

Villy Kourafalou —
George Halliwell —