Cycle Boundary Conditions setting

[Keke]

Hello everyone.

       I want to set-up a 1.00 degree resolution quasi global ocean domain (0E-360E, -70S-66N) model. I don’t know how to set up Cycle Boundary Conditions to link West Boundary to East Boundary. The longitude domain (P grid points) whether should be [0.5, 359.5] or [0.5, 360.5], and with the latter case how to set the values ( temperature, salinity and others) on grid 0.5 equal to the values on grid 360.5. I would be thankful if anyone could show me some details about how to set it?

Thanks very much.

Keke.

[alexand...@gmail.com]

Hi Keke, 

In HYCOM, the periodic/cycle E-W boundary condition is automatic as long as you have points with an ocean depth superior to 0 in your last column (i=itdm). To see how it is done, look for lperiod in bigrid.F. There is also no folding on the boundaries so no need to have special treatments for T, S and others. 

Regards, 

Alex

[Alan]

To expand on "no folding".  The HYCOM domain is 0 to 359 degrees (say) with 359 automatically preceeding 0 and 0 automatically following 359. 

We normally define the grid w.r.t. the cell centers (the p-grid), so this would be 0.5 to 359.5 in your example.

Alan.