Difference between revisions of "Numerical Solution Technique"

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==Vertical and Horizontal Discretization==
==Vertical and Horizontal Discretization==


The ROMS governing equations are discretized over variable topography using a stretched, terrain-following, vertical coordinate.  As a result, each grid cell may have different level thickness (Hz) and volume. The model state variables are vertically staggered so that horizontal momentum (u,v), density, and tracers (active and passive) are located at the center of the grid cell. The vertical velocity (ω, w) and vertical mixing variables (Akt, Akv, etc) are located at the bottom and top faces of cell, as illustrated below.
The ROMS governing equations are discretized over variable topography using a stretched, terrain-following, vertical coordinate.  As a result, each grid cell may have different level thickness (Hz) and volume. The model state variables are vertically staggered so that horizontal momentum (u,v), density, and tracers (active and passive) are located at the center of the grid cell. The vertical velocity (ω, w) and vertical mixing variables (Akt, Akv, etc) are located at the bottom and top faces of cell. See diagram below.


[[Image:vertical_grid.png|ROMS vertical grid]]
[[Image:vertical_grid.png|ROMS vertical grid]]

Revision as of 18:53, 27 February 2008

Numerical Solution Technique

Vertical and Horizontal Discretization

The ROMS governing equations are discretized over variable topography using a stretched, terrain-following, vertical coordinate. As a result, each grid cell may have different level thickness (Hz) and volume. The model state variables are vertically staggered so that horizontal momentum (u,v), density, and tracers (active and passive) are located at the center of the grid cell. The vertical velocity (ω, w) and vertical mixing variables (Akt, Akv, etc) are located at the bottom and top faces of cell. See diagram below.

ROMS vertical grid

ROMS staggered rho grid


ROMS staggered u grid


ROMS staggered v grid

Time-Stepping

Horizontal and Vertical Advection

Pressure Gradient