[MITgcm-support] Re: single-layer configuration problem update

[Sergey Vinogradov]

Martin:
I don't know of any other way than EXF to introduce the variable forcing 
into the mitgcm. The resulting field is not exploding though, it stays 
equal to i.c.
Anyway, SINGLE_LAYER_MODE is probably what I was looking for in a 
context of my experiments.
Thank you,
Sergey
 
Martin Losch wrote:

> Sergey,
> that's really puzzling. Have you tried the same thing without the 
> EXF-package? (I have had unexpected behavior with this package before).
>
> However, if --- as you suspect --- no forcing fields introduced by EXF 
> is not "felt" by the model, then it wouldn't explode, but would just 
> keep quiet without moving at all. So I think, that on the contrary, 
> the model feels too much of the forcing; or something completely 
> different is going on.
>
> I can't remember your configuration, and obviously, I am too stupid to 
> search the MITgcm-support email list effectively so I didn't find your 
> previous emails, but were you using the CPP-flag SINGLE_LAYER_MODE 
> (kicks out most of thermodynamics)? However, even if you were using 
> it, I don't see where it should interfere with the EXF package.
>
> Martin
>
> On Aug 30, 2005, at 3:49 PM, Sergey Vinogradov wrote:
>
>>  Hi all,
>>
>>  I just want to update you on my quest in solving the problem with 
>> single-layer run under dynamic forcing (and maybe get some useful 
>> feedback from you).
>>
>>  The issue was erroneous computation of ocean dynamics (sea-level, 
>> bottom pressure) in a single layer configuration with a use of EXF 
>> package interface for the time-varying atm. pressure loading.
>>
>>  Appearently, it is not a problem of just pressure loading. It is far 
>> more general problem, as I tried similar experiment with wind stress. 
>> It looks like any forcing that is introduced through EXF in one-layer 
>> run, is not "felt" by the model.
>>
>>  Below is the exerpt from the model output with one layer under wind 
>> stress at the beginning of forward integration where you can see the 
>> error accumulating in cg solver with each step. Similar run with 23 
>> layers computes reasonable fields.
>>
>>  I'd appreciate any suggestions/comments/tips very much!
>>  Regards,
>>  Sergey
>>
>> (PID.TID 0000.0001) // 
>> =======================================================
>>  (PID.TID 0000.0001) // End MONITOR dynamic field statistics
>>  (PID.TID 0000.0001) // 
>> =======================================================
>>  (PID.TID 0000.0001)  MDSREADFIELD: opening global file: 
>> /anvil/scratch/day07/svv/forcing/NCEP_R6_ustr_1999
>>  (PID.TID 0000.0001)  MDSREADFIELD: opening global file: 
>> /anvil/scratch/day07/svv/forcing/NCEP_R6_ustr_1999
>>   cg2d: Sum(rhs),rhsMax =   5.83105612406154E-15  2.52789606828280E+01
>>   cg2d: Sum(rhs),rhsMax =   4.66381008031730E-09  2.03846096766287E+01
>>   cg2d: Sum(rhs),rhsMax =  -7.72491057666330E-11  1.63318316358843E+02
>>   cg2d: Sum(rhs),rhsMax =   7.82384650122037E-10  3.94671184216402E+02
>>   cg2d: Sum(rhs),rhsMax =   1.84482164570718E-10  1.39786242903642E+03
>>   cg2d: Sum(rhs),rhsMax =  -3.86795120889058E-10  5.51987500042437E+03
>>   cg2d: Sum(rhs),rhsMax =   5.60930842031203E-10  2.96468380272229E+04
>>   cg2d: Sum(rhs),rhsMax =  -4.60258786649532E-11  1.03144921478204E+06
>>   cg2d: Sum(rhs),rhsMax =   1.93486835808804E-12  3.16417950241384E+08
>>   cg2d: Sum(rhs),rhsMax =  -2.47236726757771E-12  2.35353664301718E+13
>>   cg2d: Sum(rhs),rhsMax =  -3.50420466366502E-16  2.44341352738558E+23
>>   cg2d: Sum(rhs),rhsMax =  -2.42051059455915E-16  1.68257839407874E+43
>>   cg2d: Sum(rhs),rhsMax =  -2.02970152146811E-16  1.42078931888867E+83
>>   cg2d: Sum(rhs),rhsMax =  -4.29685153894816E-16  9.27740314802081+162
>>   cg2d: Sum(rhs),rhsMax =                    NAN                   INF
>>   cg2d: Sum(rhs),rhsMax =                    NAN  0.00000000000000E+00
>>   cg2d: Sum(rhs),rhsMax =                    NAN  0.00000000000000E+00
>>   cg2d: Sum(rhs),rhsMax =                    NAN  0.00000000000000E+00
>>  (PID.TID 0000.0001)  MDSREADFIELD: opening global file: 
>> /anvil/scratch/day07/svv/forcing/NCEP_R6_ustr_1999
>>   cg2d: Sum(rhs),rhsMax =                    NAN  0.00000000000000E+00
>>   cg2d: Sum(rhs),rhsMax =                    NAN  0.00000000000000E+00
>>
>
>
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