[MITgcm-support] problem of open boundary

[Tongya Liu]

Hi all,

I met a very strange prolem in my model recently. My model terrain is 109-135E&0-30N(the grid is 360*300). The northern,eastern and southern boundary are open boundaries. HYCOM flow feild is used to supply the open boundary velocity. But there is a strong northward flow just close to the eastern boundary, whose velocity and direction is quite different from the eastern boundary. It seems that the boundary input didn't work in this place.  This strange flow has influenced the interior circulation. I adjusted the boundary velocity and the boundary conditions, but it still exist.


I show the result in this web: http://photo.blog.sina.com.cn/photo/1955901475/0028mLjZgy6R7I55jUIf0#pic

Please give me some advices. Thanks very much.

Tongya Liu

data:


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

 viscAr=1.77E-3,
 viscAh=100,
 diffKhT=0,
 diffKrT=3E-5,
 diffKhS=0,
 diffKrS=3E-5,
 useFullLeith=.TRUE.,
 viscC4Leith=1.5,
 viscC4Leithd=1.5,
 viscA4GridMax=1.0,
 useAreaViscLength=.TRUE.,
 useAnisotropicViscAGridMax=.TRUE.,
 tempAdvScheme=33,
 saltAdvScheme=33,
 eosType = 'JMD95Z',
 multiDimAdvection=.TRUE.,
 vectorInvariantMomentum=.TRUE.,

 no_slip_sides=.FALSE.,
 no_slip_bottom=.TRUE.,
 bottomDragQuadratic=0.0025,
 implicitDiffusion=.TRUE.,
 implicitFreeSurface=.TRUE.,
 implicitViscosity=.TRUE.,
 staggerTimeStep=.TRUE.,
 implicitFreeSurface=.TRUE.,
 exactConserv=.TRUE.,
 hFacMin=0.3,
 hFacMindr=50.,
 hFacInf=0.1,
 hFacSup=5.,
 readBinaryPrec=64,
#- not safe to use globalFiles in multi-processors runs
 globalFiles=.TRUE.,
 useSingleCpuIO=.TRUE.,
 &

# Elliptic solver parameters
 &PARM02
 cg2dMaxIters=500,
 cg2dTargetResidual=1.E-5,
 &

# Time stepping parameters
 &PARM03
 nIter0=        0,
 nTimeSteps = 25920,
#nTimeSteps = 200,
#startTime=0.,
#endTime=311040000.,
 basetime=0,
 deltaT=1200.0,
 abEps=0.1,
 momDissip_In_AB=.FALSE.,
 dumpFreq=864000,
 pChkptFreq=31104000.,
 chkptFreq=2592000.,
 monitorSelect=2,
 monitorFreq=864000.,

 &

# Gridding parameters
 &PARM04
 usingSphericalPolarGrid=.TRUE.,
 ygOrigin=0.0,
 xgOrigin=99.,
 dxSpacing=0.1,
 dySpacing=0.1,
 delR=30.,30.,30.,30.,30.,30.,
       30.,30.,30.,30.,30.,30.,
       30.,30.,30.,30.,30.,30.,
       30.,30.,50.,50.,100.,200.,
       300.,500.,600.,800.,800.,1000.,
 &

# Input datasets
 &PARM05
 bathyFile='topog.bin',
 hydrogThetaFile='Temp.bin',
 hydrogSaltFile='Salt.bin',

 &


data.obcs

# Open-boundaries
 &OBCS_PARM01
# open boundaries.
 OBCSfixTopo=.FALSE.,
 OB_Jnorth= 360*-1,
 OB_Jsouth= 360*1,
 OB_Ieast = 300*-1,

 useOBCSprescribe = .TRUE.,
#useOBCSsponge=.TRUE.,
 
 useOBCSbalance=.TRUE.,
 OBCS_balanceFacN= 1.,
 OBCS_balanceFacS= 1,
 OBCS_balanceFacE= 1.,

 OBNuFile = 'HY_NorthU.bin',
 OBSuFile = 'HY_SouthU.bin',
 OBEuFile = 'HY_EastU.bin',
 OBNvFile = 'HY_NorthV.bin',
 OBSvFile = 'HY_SouthV.bin',
 OBEvFile = 'HY_EastV.bin',

 OBNsFile = 'snorth.bin',
 OBNtFile = 'tnorth.bin',
 OBEsFile = 'seast.bin',
 OBEtFile = 'teast.bin',
 OBSsFile = 'ssouth.bin',
 OBStFile = 'tsouth.bin',

 OBCS_monitorFreq= 2592000.,
 OBCS_monSelect = 1,
 &

# *****************************************
# Sponge Layer Parameters.
# *****************************************
 &OBCS_PARM03
 Urelaxobcsinner=432000.E0,
 Urelaxobcsbound=43200.E0,
 Vrelaxobcsinner=432000.E0,
 Vrelaxobcsbound=43200.E0,
 spongeThickness=30,
 &









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