[MITgcm-support] Re : Query regarding "exf package".

[Martin Losch]

Himansu,

for constant wind stress (one time slice) you need to have u/vtressperiod = 0. (which is the default if you do not specify anything) in data.exf, otherwise the model is trying to read the next field at t=t0+u/vstressperiod.

Further, readstressOnAgrid=.TRUE., makes the model believe that the stress components are defined on the center points of the C-grid (I think), so that they are interpolated to the U/V points. Specifying 
 zonalWindFile='pUstress.bin',
 meridWindFile='pVstress.bin',
in data&PARM05 assumes stress at U/V points automatically. Set readStressOnCgrid = .true., if you want to do the same in with pkg/exf.

Martin
On Jan 9, 2012, at 7:57 AM, himansu pradhan wrote:

> hi MITgcm users,
> 
> A doubt to clarify 
> 
> My u/v-windstress file is of one time slice (157 * 133) . This is what i was using in "data" file . 
> *******data******
>  &PARM03
>  startTime=0,
>  endTime=864000,
>  deltaT=10.0,
>  abEps=0.1,
> # momDissip_In_AB=.FALSE.,
>  pChkptFreq=432000,
> # chkptFreq=432000,
>  dumpFreq=21600,
>  &
> # Input datasets
>  &PARM05
>  bathyFile='top_MOD.bin',
>  hydrogThetaFile='15lvlT_may.bin',
>  hydrogSaltFile='15lvlS_may.bin',
> # zonalWindFile='pUstress.bin',
> # meridWindFile='pVstress.bin',
> &
> but when i use the SAME u/v- windstress file (157*133) in "data.exf" . The model didnot run ..!!!!!!!!
> # *********data.exf************
> # External Forcing Data
> # *********************
>  &EXF_NML_01
>  exf_iprec         = 64,
>  readstressOnAgrid=.TRUE.,
>  useExfCheckRange=.FALSE.,
>  &
>  &EXF_NML_02
>  ustressstartdate1=20110101,
>  ustressstartdate2=000000,
>  ustressperiod=864000,
> #
>  vstressstartdate1=20110101,
>  vstressstartdate2=000000,
>  vstressperiod=864000,
> #
>  ustressfile  = 'pUstress.bin',
>  vstressfile  = 'pVstress.bin',
>  &
> [....]
> 
> finally,
> i created u/v- windstress file having 2 time slabs (i.e. 157*133*2)............ The model "runs" SUCESSFULLY for the total period of intergration. . 
> 
> my doubt is : 
> 
> (a) why i need to give 2 time slabs (157*133*2)  in "data.exf".....??? (whereas, In "data" i use only one time slab(157*133) for the complete period of integration)
> 
> Am i doing right here  ??? 
> 
> 
> Thank you , 
> 
> Himansu Kesari Pradhan,
> India.
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