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

David Wang dwang at ldeo.columbia.edu
Tue Aug 30 13:45:54 EDT 2005


Hey all,

I try to catch up this thread and throw out my question.

If I use exf package to specify my wind stress forcing (monthly 
climatology) and restoring SST/SSS (also monthly climatology), do the 
following parameters in data namelist still count? I've not found the 
counterpart of externForcingCycle (supposed to be 1 year in my case) in 
data.exf and data.exf_clim namelists.

periodicExternalForcing
externForcingPeriod
externForcingCycle
tauThetaClimRelax
tauSaltClimRelax

Thanks,
- D.W.

Patrick Heimbach wrote:

>Sergey,
>
>several things:
>1. I thought you were using the SINGLE_LAYER_MODE flag(?)
>2. The std. output has NAN's in cg2d after a few timesteps,
>   but you're saying the model doesn't explode.
>   Can you clarify?
>3. The alternative, simplere forcing would be via
>   S/R external_fields_load.F
>   and not using exf (i.e. remove 'exf' from packages.conf)
>   An example is in verification/global_ocean.90x40x15/code/
>
>-Patrick
>
>
>
>  > -----Original Message-----
>  > From: mitgcm-support-bounces at mitgcm.org 
>  > [mailto:mitgcm-support-bounces at mitgcm.org] On Behalf Of 
>  > Sergey Vinogradov
>  > Sent: Tuesday, August 30, 2005 10:50 AM
>  > To: mitgcm-support at mitgcm.org
>  > Cc: Rui Ponte
>  > Subject: Re: [MITgcm-support] Re: single-layer 
>  > configuration problem update
>  > 
>  > 
>  > 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
>  > >>
>  > >
>  > >
>  > > _______________________________________________
>  > > MITgcm-support mailing list
>  > > MITgcm-support at mitgcm.org
>  > > http://mitgcm.org/mailman/listinfo/mitgcm-support
>  > 
>  > 
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>
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-- 
Daiwei (David) Wang	 Graduate Student
Lamont-Doherty Earth Observatory of Columbia University
103B Oceanography
61 Route 9W, Palisades, NY 10964-8000
Voice: (845) 365-8694 




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