NOAA

Geophysical Fluid
Dynamics Laboratory

Skip to: [content] [navigation]
If you are using Navigator 4.x or Internet Explorer 4.x or Omni Web 4.x , this site will not render correctly!

gfdl's home page > gfdl on-line bibliography > 1998: Monthly Weather Review, 126(12), 3248-3270

Transient response in a Z-level ocean model that resolves topography with partial cells

Pacanowski, R. C., and A. Gnanadesikan, 1998: Transient response in a Z-level ocean model that resolves topography with partial cells. Monthly Weather Review, 126(12), 3248-3270.
Abstract: Ocean simulations are in part determined by topographic waves with speeds and spatial scales dependent on bottom slope. By their very nature, discrete z-level ocean models have problems accurately representing bottom topography when slopes are less than the grid cell aspect ratio delta z/delta x. In such regions, the dispersion relation for topographic waves is inaccurate. However, bottom topography can be accurately represented in discrete z-level models by allowing bottom-most grid cells to be partially filled with land. Consequently, gently sloping bottom topography is resolved on the scale of horizontal grid resolution and the dispersion relation for topographic waves is accurately approximated. In contrast to the standard approach using full cells, partial cells imply that all grid points within a vertical level are not necessarily at the same depth and problems arise with pressure gradient errors and the spurious diapycnal diffusion. However, both problems have been effectively dealt with. Differences in flow fields between simulations with full cells and partial cells can be significant, and simulations with partial cells are more robust than with full cells. Partial cells provide a superior representation of topographic waves when compared to the standard method employing full cells.
smaller bigger reset
last modified: March 23 2004.