[MITgcm-devel] vectorizing seaice and exf

[Patrick Heimbach]

Hi Martin,

if I remember correctly,
the safeguard in case of #ifdef ALLOW_ATM_WIND
was to define
            sh(i,j,bi,bj) = MAX(wspeed(i,j,bi,bj),uMin)
so as to avoid vanishing ustar:
            ustar(i,j)  = rdn(i,j)*sh(i,j,bi,bj)

The analogue would be to define a wStress pendant
that is always nonzero, and use this one instead of
            tau(i,j)    = wStress(i,j,bi,bj)
            ustar(i,j)  = sqrt(tau(i,j)/atmrho)

Is this OK or does this give rise to spurious motions?
(case wstress == 0 should be highly unlikely in open ocean)

-p.

On Sep 28, 2007, at 3:51 AM, Martin Losch wrote:

> Hi,
>
> I just checked in my new exf_bulkformulae.F
> Patrick, please check, if it does not break the adjoint.
>
> One issue remains (nothing to do with vectorization):
> Jean-Michel, I remember that we talked about this already, but I  
> forgot the solution. For the case that I want to read wind stress  
> along with ALLOW_BULKFORMULAE (#undef ALLOW_ATM_WIND), the field  
> wStress is computed from input-fields sqrt(ustress^2+vstress^2). If  
> stress=0 (for some reason), ustar=0 in exf_bulkformulae resulting  
> in a division by zero. Do we want to safeguard against that? And if  
> so, how? Add a minimum wstress or ustar?
>
> Martin
>
> On 27 Sep 2007, at 22:47, Patrick Heimbach wrote:
>
>> Martin,
>>
>> great news.
>> I reckon you are confident that the
>>     IF (atemp ... = 0) THEN
>> doesn't cause additional problems...
>>
>> Re. routine, I had a quick look, and it seems ok.
>> One thing is that the store directives for
>> rdn, ustar, qstar, tstar, tau
>> are now broken.
>> Could you add "(i,j)" to these?
>>
>> I guess you'll run testreport before checkin(?)
>>
>> Cheers
>> -Patrick
>
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