[MITgcm-support] Question about RBCS gridding in rbcs_add_tendency.F

[Katarina Merk]

Dear all,

I’m encountering some unexpected behavior with the RBCS package. Specifically, the relaxation doesn't always seem to have the effect that I expect. 

While looking through the code, I came across a section in rbcs_add_tendency.F that did not make sense to me. The loops for the relaxations is currently written like:

     IF ( tracerNum.EQ.1 .AND. useRBCtemp ) THEN
        irbc = MIN(maskLEN,tracerNum)
        rec_tauRlx = rbcsVanishingFac/tauRelaxT
        DO j=0,sNy+1
         DO i=0,sNx+1
          gTendency(i,j) = gTendency(i,j)
     &       - RBC_mask(i,j,k,bi,bj,irbc)*rec_tauRlx
     &        *( theta(i,j,k,bi,bj)- RBCtemp(i,j,k,bi,bj) )

         ENDDO
        ENDDO
      ENDIF

Should this instead use halo-aware indexing like:

      DO j = 1-OLy, sNy+OLy
       DO i = 1-OLx, sNx+OLx
Is the current gridding intentional, or could this be contributing to the relaxation issues I’m seeing?

Thanks for your time and help!

Best,
Katarina
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.mitgcm.org/pipermail/mitgcm-support/attachments/20250610/a875b7bf/attachment.html>