depths on the supergrid

[ezaron]

Hi MOM6 Enthusiasts:

I have a (logically-rectangular) global tripolar supergrid. And I have a separate file with ocean depth at the cell-centers.

How is the depth computed at the cell-faces (u and v points) for use in the continuity equation and momentum equations? Does there exist an option to input depth at all nodes of the supergrid so that the depths at u and v nodes could be specified independently?

-Ed

 

[kshedstrom@alaska_edu]

MOM6 does not have a way to input depths other than at cell centers. Are you hoping to follow the true bumpy bathymetry at a higher resolution? It would probably break the continuity solver or some such thing, which assumes smooth shapes for bathymetry within a grid cell.

 

[ezaron]

Thanks, Kate. On an Arakawa C-grid, the depth ought to only be needed on the U- and V-nodes, at least for a simple barotropic solver, so I was curious if there was a way to separately prescribe the depths of these nodes from the input files (such as by using the "supergrid" file).

 

[adcroft]

He Wang is close to finishing the implementation of porous barriers which includes a bathymetry specific to the u- and v-points. But as Kate says, at this time the grid is based on h-cells. The supergrid is at twice the resolution solely to describe the grid without redundancy (it avoids naming 20+ metric and coordinate variables at the native resolution).