[MITgcm-support] Problem with KPP

[Martin Losch]

Abbas,

in fact, the model is blowing up, your compiler just continues to  
work with NaN's. Some compilers can do that, which is often annoying.

You need to have a closer look at what's going on by setting you  
moniterFreq to a lower value (it's only in this package, where the  
model checks for a run-away theta), and by producing output to see,  
where stuff blows up first (location and variables). I suspect a cfl- 
problem, but based on your information it could be anything ...

Martin

On 5 Jun 2008, at 20:41, Abbas Dorostkar wrote:

> Hi all,
> I am simulating internal waves in a lake. The model without using KPP
> scheme works well. However, when I implement KPP, it does not blow up
> but I get NAN in output.txt. I wonder what is going wrong. Your  
> help is
> much appreciated.
> I have attached some part of output.txt, data, data.kpp
>
>  (PID.TID 0000.0001)  exf_GetFFieldsRec: first, changed, fac:   F   F
> 0.80000000D+00
> (PID.TID 0000.0001)  exf_GetFFieldsRec: myiter, count0, count1:     24
> 1      2
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
> (PID.TID 0000.0001)  exf_GetFFieldsRec: first, changed, fac:   F   F
> 0.80000000D+00
> (PID.TID 0000.0001)  exf_GetFFieldsRec: myiter, count0, count1:     24
> 1      2
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
>  cg2d: Sum(rhs),rhsMax =                    NaN  4.05115865207719+303
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
> (PID.TID 0000.0001)  exf_GetFFieldsRec: first, changed, fac:   F   F
> 0.79166667D+00
> (PID.TID 0000.0001)  exf_GetFFieldsRec: myiter, count0, count1:     25
> 1      2
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
> (PID.TID 0000.0001)  exf_GetFFieldsRec: first, changed, fac:   F   F
> 0.79166667D+00
> (PID.TID 0000.0001)  exf_GetFFieldsRec: myiter, count0, count1:     25
> 1      2
> (PID.TID 0000.0001)  exf_GetFFieldsRec:
>  cg2d: Sum(rhs),rhsMax =                    NaN                   NaN
>
> -------------------------------------------------
> # Continuous equation parameters
>  &PARM01
>  Tref =,
>  sRef=0.,
>  viscAz=1.E-3,
>  viscAh=1.0E-2,
>  viscA4=0.E12,
>  no_slip_sides=.FALSE.,
>  no_slip_bottom=.FALSE.,
>  diffKhT=1.E-2,
>  diffKzT=1.E-3,
>  f0=0.0,
>  beta=0.E-11,
>  tAlpha=2.E-4,
>  sBeta =0.E-4,
>  rigidLid=.FALSE.,
>  implicitFreeSurface=.TRUE.,
>  eosType='LINEAR',
>  nonHydrostatic=.FALSE.,
>  readBinaryPrec=32,
>  writeBinaryPrec=32,
>  writeStatePrec=32,
>  saltStepping=.FALSE.,
>  hFacMin=0.2,
>  implicitViscosity=.TRUE.,
>  implicitDiffusion=.TRUE.,
> &
> # Elliptic solver parameters
>  &PARM02
>  cg2dMaxIters=1000,
>  cg2dTargetResidual=1.E-12,
>  cg3dMaxIters=400,
>  cg3dTargetResidual=1.E-12,
>  &
> # Time stepping parameters
>  &PARM03
>  niter0=0,
>  startTime=0.0,
>  endTime=604800,
>  deltaT=5.,
>  abEps=0.1,
>  pChkptFreq=0.0,
>  chkptFreq=0.0,
>  dumpFreq=200,
>  monitorFreq=1000,
>  &
> # Gridding parameters
>  &PARM04
>  usingCartesianGrid=.TRUE.,
>  usingSphericalPolarGrid=.FALSE.,
>  delX=546*99.880952381,
>  delY=3000.,
>  delRFile='delz.grid',
> #delZ=132*1.000649793,
>  &
> ----------------------
> # KPP parameters
>  &KPP_PARM01
>  KPPmixingMaps   = .FALSE.,
>  KPPwriteState   = .TRUE.,
>  KPP_ghatUseTotalDiffus=.FALSE.,
>  &
>
>
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