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: Journal of Physical Oceanography, 28(11), 2163-2174

Simulation of density-driven frictional downslope flow in z-coordinate ocean models

Winton, M., R. Hallberg, and A. Gnanadesikan, 1998: Simulation of density-driven frictional downslope flow in z-coordinate ocean models. Journal of Physical Oceanography, 28(11), 2163-2174.
Abstract: An important component of the ocean's thermohaline circulation is the sinking of dense water from continental shelves to abyssal depths. Such downslope flow is thought to be a consequence of bottom stress retarding the alongslope flow of density-driven plumes. In this paper the authors explore the potential for explicitly simulating the simple mechanism in z-coordinate models. A series of experiments are performed using a twin density-coordinate model simulation as a standard of comparison. The adiabatic nature of the experiments and the importance of bottom slope make it more likely that the density-coordinate model will faithfully reproduce the solution. The difficulty of maintaining the density signal as the plume descends the slope is found to be the main impediment to accurate simulation in the z-coordinate model. The results of process experiments suggest that the model solutions will converge when the z-coordinate model has sufficient vertical resolution to resolve the bottom viscous layer and horizontal grid spacing equal to its vertical grid spacing divided by the maximum slope. When this criterion is met it is shown that the z-coordinate model converges to an analytical solution for a simple two-dimensional flow.
smaller bigger reset
last modified: March 23 2004.