Help in boundary conditions options in cppdefs.h


I am confused about switiching on boundary conditions options in cppdefs.h.
I am trying to set up a simulation as close as possible to a ROMS_RUTGERS simulations.
This is a realistic coastal model having wind, tides, rivers, bulk forcing, etc.

In the ROMS_RUTGERS, I am using the following boundary conditions in the input text file ( which is similar to The boundary conditions are shown in this image:

What are the correct equivalent options for croco? My case has North boundary closed.

Currently I have the following cpp option in my croco cppdefs.h file:

Am I using the correct OBC options? Because I am getting a blow up after few time steps. Reducing the dt and ndtfast is just delaying the blowup. I am attaching my full cppdefs.h here.

I am using boundary forcing file and not climatology file. Here is the metadat of my bry forcing file: bry.txt

Any suggestion and help will be much appreciated.


If you want to use boundary forcing, you need to define FRC_BRY (not done in your cppdefs.h).

Then, the choice of OBC keys seen in your cppdefs.h is equivalent to your ROMS-Rutgers configuration. However, OBC_M2CHARACT is an improvement to OBC_M2FLATHER (same physics, better numerics) and is advised instead. It is the default choice in recent CROCO versions.

Nudging is part of ORLANSKI choices and nudging parameters (for inward and outward radiations) are inserted in

Thanks! It seems to be working. And my guess is the M2/M3SPECIFIED is equivalent to the ‘CLAMPED’ condition in roms_rutgers, just for future reference?

It would be great to get confirmation what exactly “SPECIFIED” means for M2/M3/T.