[MITgcm-support] OB*file interpolation

[Riema Rachmayani]

dear MITgcm,





 
sorry i send message again in
other subject...this is about OB *file
interpolation, my previous message was about  baroclinic, barotropic and
bathyfile...
 

 
 

Martin,
i'm trying your suggestion about OB file in
your last message :
 

Martin :
 

exp4 gives an example of how to specify CONSTANT (in time)
open  

boundary values from files:

  useOBCSprescribe = .TRUE.,
(enables reading from files in general)

  OBNuFile = 'OBmeridU.bin',
(example of a file)

[...]

these files were generated with
exp4/input/gendata.m. The script tell  

you that a filed for the northern
(southern) boundary should have the  

dimension (nx,nr) and for eastern
(western), (ny,nr).
 

 
 

in
data.obcs of exp4 :
 

#
OBNuFile = 'OBmeridU.bin',

# OBSuFile = 'OBmeridU.bin',

# OBWuFile = 'OBzonalU.bin',

# OBEuFile = 'OBzonalU.bin',

# OBWsFile = 'OBzonalS.bin',
 

  
 

i
checked dimension of OBmeridU ==> (80,8) for 2 iteration time independent ??
 

i
checked dimension of OBzonalU ==> (42,8) for 2 iteration time independent ??
 

 
 

Martin
:
 

If you want to specify time dependent boundary values you can do
that  

too. For example, you have hourly data
you have create a field  

(nx,nr,nt), where nt is the number of
"hours" you have. and then you  

use the parameters

  
periodicExternalForcing=.TRUE.,

   externForcingPeriod=3600.,

in the file "data", in
namelist PARM03. If your data is the same  

after say 12 hour (ie., that you want
to use the fields repeatedly)  

then add this parameter in data

  externForcingCycle=43200.,
 

 
 

in data
file my case :
 

# Time
stepping parameters

 &PARM03

 niter0=0,

 nTimeSteps=1641600,

 deltaT=1.5,

 abEps=0.1,

 pChkptFreq=0.0,

 chkptFreq=0.0,

 dumpFreq=11160.,

 monitorFreq=2500.,

# for time dependent open boundary
conditions comment 

# in the following three lines

 periodicExternalForcing=.TRUE.,

 externForcingPeriod=3600.,

 externForcingCycle=1641600.,

 &
 

  
 

is that
correct???
 

  
 

i have
value of velocity at one point for 19 days (attachment file
=U_AOK.IN), that file just for an example, i have other file for other
point. I mean i pick out a point to other point, for example at north open
boundary, i picked out point A (tip point at
west)==>(Nx,Ny,Nr)==>(1,1,1), and then i picked out point B (tip point at
east))==>(Nx,Ny,Nr)==>(111,1,1). 
 

 
 

i still
confused, in my attachment file U_AOK.IN, i only have 1 value for
1 point every 1 hour for 19 days like i told you before, mean while in exp4
case, OBmeridU was already in (nx,nr,nt)==>(80,8,2)...so in data.obcs wrote
OBNuFile = 'OBmeridU.bin, what about my case? i only have 1 point for
19 days
 

 
 

what i
want to do is to interpolate value in U_AOK.IN in spatial (inner of
point A and point B) and in time just like you said...(Martin : Forgot to say: the model
does the interpolation in time to each   timestep, but that's "only" a linear
interpolation)
 

  
 

so what
i have to do with my U_AOK.IN file to get what i
want?? interpolate in time first (how the code configuration in data file or
data.obcs or other routine) and then interpolate in spatial (how the code
configuration in data file or data.obcs or other routine) or vice versa??? 
 

  
 

thank
you martin, i hope my questions is clear enough for you...
 

i'll
wait for your reply...i really need this...
 

thank
you...
 

best
regards,
 

rima
 

  
 

 







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