[MITgcm-devel] Re: downslope pkg

[Martin Losch]

Hi Jean-Michel,
the masking is absolutely necessary for the shelfice package in the  
current implementation (who gave this package this stoopid name, some  
German idiot!), because otherwise the model integrates some  
ridiculous density (for Theta=Salt=0, or even worse from some other  
arbitrary Theta and Salt) from the top for phiHyd. When  
useShelfice=.true. you are supposed to provide a reference pressure  
at the bottom of the ice shelf and integrating phiHyd from the very  
top (k=1) is not necessary. JMD95P and MDJFW should work with  
shelfice, too, for this reason.  I don't know about the downSlope  
package. That one was not around, when I implemented shelfice.
Without the masking, one would have to use if statements in the ij- 
loops for the phiHyd intergration to determine, where the real  
intergration of phiHyd is supposed to start; not good. Alternatively,  
one could only mask alphaRho in the ice shelf, like this:
         IF ( useShelfIce ) THEN
          DO j=jMin,jMax
           DO i=iMin,iMax
            IF ( kTopC(I,J,bi,bj) .GE. k ) alphaRho(i,j) = alphaRho 
(i,j)*maskC(i,j,k,bi,bj)
           ENDDO
          ENDDO
         ENDIF
Do you have a better idea?

Martin

On 5 Sep 2008, at 18:31, Jean-Michel Campin wrote:

> Hi Michael,
>
> I found a problem with shelfice & down_slope pkgs:
> looks like useShelfIce is masking the density (in CALC_PHI_HYD)
> so that we will have a problem when using an EOS directly function
> of pressure (e.g.: JMD95P). I looked to
> MITgcm_contrib/high_res_cube/data.hr
> and it's not the case (EOS=JMD95Z).
> Can you confirm that you are not using an EOS directly function
> of pressure ?
>
> Otherwise, how is the test going ?
>
> I cc this to the devel list, so that Martin will know why I will
> bother him to remove this masking with useShelfIce ...
>
> Cheers,
> Jean-Michel
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