[MITgcm-devel] lab_sea.hb87 restart problem

[Martin Losch]

Hi Jean-Michel,

I am stuck. With the following parameters in data.seaice
> &SEAICE_PARM01
>   SEAICEwriteState   = .TRUE.,
>   SEAICE_initialHEFF = 1.0,
>   SEAICE_deltaTtherm = 3600.,
>   SEAICE_deltaTdyn   = 3600.,
> # useHB87stressCoupling = .true.,
>   SEAICE_no_slip     = .TRUE.,
>   SEAICE_deltaTevp   = 60.,
I can get a perfect pickup, if I set hFacU to zero in the if  
(SEAICE_no_slip) block in seaice_calc_strainrates.F like this:
>            hFacU = _maskW(i,j,k,bi,bj) - _maskW(i,j-1,k,bi,bj)
>            hFacV = _maskS(i,j,k,bi,bj) - _maskS(i-1,j,k,bi,bj)
>            hFacU = 0. _d 0
> CML           hFacV = 0. _d 0
>
>            e12(I,J,bi,bj) = e12(I,J,bi,bj)
>      &          + recip_rAz(i,j,bi,bj) *
>      &          ( hFacU * ( _dxC(i,j-1,bi,bj)*uFld(i,j  ,bi,bj)
>      &                    + _dxC(i,j,  bi,bj)*uFld(i,j-1,bi,bj) )
>      &          + hFacV * ( _dyC(i-1,j,bi,bj)*vFld(i  ,j,bi,bj)
>      &                    + _dyC(i,  j,bi,bj)*vFld(i-1,j,bi,bj) ) )
>      &         - hFacU
>      &         * 0.25 _d 0 * (uFld(I,J,bi,bj)+uFld(I  ,J-1,bi,bj))
>      &         * ( _tanPhiAtU(I,J,bi,bj) + _tanPhiAtU(I,J-1,bi,bj) )
>      &         *recip_rSphere
This means, that at least the no-slip problem is related to uIce. But  
it cannot be directly related to uice, because the pickup (and this  
piece of code) is ok for many other cases (e.g. LSR). Somewhere the  
true problem is masked. I don't have a clue. I don't even know what  
to test next ...

Martin


On 9 Nov 2007, at 17:40, Jean-Michel Campin wrote:

> Hi Martin,
>
> I don't know much about the cause of the problem,
> but you narrow down quiet well where it sould be.
>
> I agree that it should not be too difficult to
> make this tst1+1 script more tolerent regarding blanks
> upper-case/lower case.
>
> I have a general question:
> What about adding few "data.tst" in some verification/*/input  
> experiments
> to facilitate those kind of test ? I am not sure it's a good
> idea, but would interesting to know what other people think.
>
> Cheers,
> Jean-Michel
>
> On Fri, Nov 09, 2007 at 05:21:37PM +0100, Martin Losch wrote:
>> OK, there error was somewhere between keyboard and chair: your script
>> is case sensitive and I was sloppy in editing data.tst.
>>
>> Now I have repeated the tests with your script and this is what I  
>> get:
>> original lab_sea.hb87
>>> csysm3::tr_run.hb87> ./tst1+1 2
>>> 10 12 14
>>> 0000000010 0000000012 0000000014
>>> gcmExc=mitgcmuv
>>> -- compare cg2d_init_res :
>>> run 1iA:
>>>    6.08551932893086E-02
>>>    6.55586521348751E-02
>>> run 1iB:
>>>    7.02066252452855E-02
>>>    7.29377130933022E-02
>>> run 2it:
>>>    6.08551932893086E-02
>>>    6.55586521348751E-02
>>>    7.01960854205512E-02
>>>    7.29481919712837E-02
>> lab_sea.hb87 with useHB87stressCoupling = .false.,
>>> csysm3::tr_run.hb87> ./tst1+1 2
>>> 10 12 14
>>> 0000000010 0000000012 0000000014
>>> gcmExc=mitgcmuv
>>> -- compare cg2d_init_res :
>>> run 1iA:
>>>    6.08586878524103E-02
>>>    6.55715983076715E-02
>>> run 1iB:
>>>    7.02079681169673E-02
>>>    7.29487338830253E-02
>>> run 2it:
>>>    6.08586878524103E-02
>>>    6.55715983076715E-02
>>>    7.02078133431693E-02
>>>    7.29489594851236E-02
>> with useHB87stressCoupling = .false., and evp turned off (#
>> SEAICE_deltaTevp   = 60.,)
>>> 10 12 14
>>> 0000000010 0000000012 0000000014
>>> gcmExc=mitgcmuv
>>> -- compare cg2d_init_res :
>>> run 1iA:
>>>    6.08355827055190E-02
>>>    1.16426574689837E-01
>>> run 1iB:
>>>    7.80912267704927E-02
>>>    7.36159469063700E-02
>>> run 2it:
>>>    6.08355827055190E-02
>>>    1.16426574689837E-01
>>>    7.80912267704927E-02
>>>    7.36159469063700E-02
>> with useHB87stressCoupling = .true., and evp turned off (#
>> SEAICE_deltaTevp   = 60.,)
>> and with useSeaice=.false.,
>>> 10 12 14
>>> 0000000010 0000000012 0000000014
>>> gcmExc=mitgcmuv
>>> -- compare cg2d_init_res :
>>> run 1iA:
>>>    6.13113158130375E-02
>>>    6.57463167891239E-02
>>> run 1iB:
>>>    7.04816593980862E-02
>>>    7.33615824658603E-02
>>> run 2it:
>>>    6.13113158130375E-02
>>>    6.57463167891239E-02
>>>    7.04816593980862E-02
>>>    7.33615824658603E-02
>>
>> My conclusions from these numbers:
>> 1. Your script is great!!!
>> 2. The restart problem is related to EVP.
>> However, I can reproduce your result in lab_sea/run, that the restart
>> does work with EVP. Puzzling. Therefore I reran the test in lab_sea/
>> run with SEAICE_no_slip = .true. (which is also used in tr_run.hb87),
>> and then:
>>> -- compare cg2d_init_res :
>>> run 1iA:
>>>    6.08981197561294E-02
>>>    6.55972956406261E-02
>>> run 1iB:
>>>    7.02007081962388E-02
>>>    7.29011820001111E-02
>>> run 2it:
>>>    6.08981197561294E-02
>>>    6.55972956406261E-02
>>>    7.02007451116285E-02
>>>    7.29010160470697E-02
>> For tr_run.lsr everything is OK even with SEAICE_no_slip = .true.
>>
>> So the problem is related to a combination of EVP and no-slip
>> boundary conditions (and not the hb87 stress formulation). Now, the
>> flag SEAICE_no_slip is not used anywhere in the EVP code, except in
>> seaice_calc_strainrates.F, which is also used by the LSR code. I
>> don't have no clue where this problem comes from. Why should break
>> this flag the pickup for the evp code only, if it is not used in the
>> code that is exclusive to EVP?
>>
>> Any idea?
>>
>> Martin
>>
>>
>>
>>
>>
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