[MITgcm-devel] Re: downslope pkg

[Jean-Michel Campin]

Hi Michael,

I will check again that it's OK to use both pkgs, iceshelf and down-slope.
regarding "the three dimensional diagnostic",
hFacC is the real mask, and you should not worry about any value of theta 
in-land, it's just there for the algorithm to work
(this will be fixed one day, but busy right now).
So, do you see, e.g, non zero velocities in-land ? or other than 
theta,salt,rho fields that appear to change in-land ?
Thanks,
Jean-Michel

PS: can you fill the subscription page to the development list:
http://mitgcm.org/mailman/listinfo/mitgcm-devel
so that we will just approve it.

On Mon, Sep 08, 2008 at 07:27:46PM -0700, Michael Schodlok wrote:
>
> Hi Jean-Michel,
>
> first I thought the combination of packages iceshelf and down-slope was  
> running without
> a problem as the STDOUT files didn't reveal anything abnormal.
> But, now it seems that the mask is lost somewhere when averaging to  
> three dimensional
> fields. While hFacC is showing land and water grid points, the three  
> dimensional diagnostic
> fields  seem to  have only the mask of one layer (the coastline)  
> throughout the water column,
> i.e., in case of iceshelves included, the cavities are outlined very  
> nicely.
> Could you please check it out:
> I've put three directories with different runs on:
>  http://ecco2.jpl.nasa.gov/data4/MPS_output/pub/MITgcm/
>
>  run_ohne: without downslope and without iceshelves
>  run_down: with downslope and without iceshelves
>  run_ice: with downslope and with iceshelves.
>  the directories include the data files, hFacC and THETA (first month  
> average).
>  the model domain is 220x220x50;
>
>  thanks
> Michael
>
>
>> 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
>>> _______________________________________________
>>> MITgcm-devel mailing list
>>> MITgcm-devel at mitgcm.org
>>> http://mitgcm.org/mailman/listinfo/mitgcm-devel
>>
>
>
> -- 
> --
> --
>
> *************************************************
>
> Michael Schodlok <schodlok at jpl.nasa.gov>
> Jet Propulsion Lab/
> California Institute of Technology
> MS 300-323
> 4800 Oak Grove Dr
> Pasadena CA 91109-8099 USA
> Tel: +1-818-354-4015  Fax: +1-818-393-6720
>
> *************************************************
>
>
>