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

Tue Aug 30 10:59:02 EDT 2005

Sergey,
the verification/global_ocean.90x40x15/input/data has an example how to 
specify time-variable forcing without the exf-pkg (compare to 
global_with_exf, which is the exact equivalent with exf):
in PARM03 you put this (this is for monthly forcing repeating itself 
after one year, put whatever you have in data.exf there, the data files 
are the same):
  periodicExternalForcing=.TRUE.,
  externForcingPeriod=2592000.,
  externForcingCycle=31104000.,
in PARM05 you put this:
  zonalWindFile=  'trenberth_taux.bin',
  meridWindFile=  'trenberth_tauy.bin',
  thetaClimFile=  'lev_sst.bin',
  saltClimFile=   'lev_sss.bin',
  surfQFile=      'ncep_qnet.bin',
The atmospheric pressure file is called "pLoadFile" or so (check in 
ini_parms.F or PARMS.h)

Martin

On Aug 30, 2005, at 4:49 PM, Sergey Vinogradov wrote:

> 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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