[MITgcm-support] model time step 'deltaTmom'

[Madhu]

Hello MITGCM Users
I am using curvilinear grid to rum the MITGCM model. Total number of grid
points are 175x200x15. The horizontal grid resolution  dx: 3- 5km and  dy:
4 -6 km. The model is running with time step 1sec, which is too small
'deltaTmom = 1.'  (for more details following is the data file used for
model run).

The issue is, I want to increase the  model time step so that the
simulations can be done faster.


#**********data***********
# ====================
# | Model parameters |
# ====================
#
# Continuous equation parameters
 &PARM01

# viscAhGrid = 0.0
 viscAh=5.E2,
 viscAz=5.E-3,
 diffKzT=1.E-4,
 diffKzS=1.E-4,
# diffKhT=0,
# diffKhS=0,

 no_slip_sides=.TRUE.,
 no_slip_bottom=.TRUE.,
 tempAdvScheme=33,
 saltAdvScheme=33,
 staggerTimeStep=.TRUE.,
 eosType='LINEAR',

 tAlpha=2.E-4,
 sBeta =2.E-6,
 gravity=9.81,
 f0=0.000001365,
 beta=1.E-11,
 hFacMin=1.,
 readBinaryPrec=64,
 writeBinaryPrec=64,

 nonHydrostatic=.FALSE.,
 rigidLid=.FALSE.,
 implicitFreeSurface=.TRUE.,
 exactConserv=.TRUE.,
 useSingleCpuIO=.TRUE.
 globalFiles=.FALSE.,
 &

# Elliptic solver parameters
 &PARM02
 cg2dMaxIters=200,
 cg2dTargetResidual=1.E-13,
# cg3dMaxIters=100,
# cg3dTargetResidual=1.E-13,
 &

# Time stepping parameters
 &PARM03
 startTime=0.,
  endTime=43200.,
 deltaTmom = 1.
 pChkptFreq=0.,
 dumpFreq=21600.,
monitorFreq=21600.,

 &

# Gridding parameters
 &PARM04
 usingCurvilinearGrid=.TRUE.,
 delZ= 5.0 , 10.0 , 20.0, 30.0, 40.0 ,
       50.0 , 60.0 , 70.0, 80.0, 90.0,
       100.0 ,200.0 ,300.0 ,400.0,500.0,
 rSphere=6370.E3,
 &

# Input datasets
 &PARM05
 bathyFile='TOPO.bin',
 zonalWindFile='Ustr.bin',
 meridWindFile='Vstr.bin',
 hydrogThetaFile='T15lev.bin',
 hydrogSaltFile='S15lev.bin',
 checkIniTemp=.false.,
 checkIniSalt=.false.,
 &

The issue is, I want to increase the  model time step so that the
simulations can be done faster.

How to increase the model time step?
If I am increasing  'deltaTmom' >1 model outputs.....  NaN.
the files 'packeges.conf' , 'CPP_OPTIONS.h' and 'data.exf'  along with the
screan output dump file 'exp1' are atteched.



Waiting for reply.

 Madhu



-- 

 Madhu
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