[MITgcm-support] Running off of the seawater

[Dustin Carroll]

Hi Tongya,

Sounds like your OBCSs are not balanced properly (i.e., you have net 
transport out of the domain). You can use obcsBalance=.TRUE. (look at 
the OBCS documentation for how to control each boundary). You can also 
do this by making the net transport on your OBCS hin files equal to 
zero.

cheers,
Dustin


On 2014/11/18 06:42, liutongya13 at mails.ucas.ac.cn wrote:
> Hi there,
> 
> I am using MITgcm to stimulate the circulation of the South China Sea,
> with the real topography and the forcing condition of climatological
> temperature, salinity and wind. And I also used the package of EXF,
> OBCS and KPP. The resolution is 0.1*0.1 degree. The north, east and
> south are open boundaries.
> 
> My run time is 10years and time step is 1000s. At the beginning of the
> run, the eta_max and eta_min are normal. But after about 6000 steps,
> the sea surface height is decreasing. At last, almost grid point's sea
> surface height become very low(about -30m). I know the sea water is
> running off from the model region. But I didn't find the error.
> 
> Any suggestion is highly appreciated!
> 
> Tongya Liu
> 
> size.h
>  & sNx = 50,
>  & sNy = 50,
>  & OLx = 3,
>  & OLy = 3,
>  & nSx = 7,
>  & nSy = 6,
>  & nPx = 1,
>  & nPy = 1,
>  & Nx = sNx*nSx*nPx,
>  & Ny = sNy*nSy*nPy,
>  & Nr = 20)
> 
> data:
> # ====================
> # | Model parameters |
> # ====================
> #
> # Continuous equation parameters
>  &PARM01
>  viscAr=1.77E-3,
>  viscAh=0,
>  viscA4=1.E8,
> 
>  diffKhT=0,
>  diffKrT=1.E-5,
>  diffKhS=0,
>  diffKrS=1.E-5,
> 
>  tempAdvScheme=33,
>  saltAdvScheme=33,
>  eosType = 'JMD95Z',
> 
>  no_slip_sides=.FALSE.,
>  no_slip_bottom=.TRUE.,
>  bottomDragQuadratic=0.0025,
>  implicitDiffusion=.TRUE.,
>  implicitFreeSurface=.TRUE.,
>  implicitViscosity=.TRUE.,
> 
>  staggerTimeStep=.TRUE.,
>  implicitFreeSurface=.TRUE.,
>  exactConserv=.TRUE.,
>  hFacMin=0.2,
>  readBinaryPrec=64,
>  useSingleCpuIO=.TRUE.,
>  &
> 
> # Elliptic solver parameters
>  &PARM02
>  cg2dMaxIters=1000,
>  cg2dTargetResidual=1.E-13,
>  cg3dMaxIters=400,
>  cg3dTargetResidual=1.E-13,
>  &
> 
> # Time stepping parameters
>  &PARM03
>  startTime=0.,
>  endTime=311040000.,
>  deltaT=1000.0,
>  abEps=0.1,
>  momDissip_In_AB=.FALSE.,
>  dumpFreq=2592000.0,
>  pChkptFreq=31104000.,
>  chkptFreq=2592000.,
>  monitorSelect=2,
>  monitorFreq=100000.,
> 
>  &
> 
> # Gridding parameters
>  &PARM04
>  usingSphericalPolarGrid=.TRUE.,
>  ygOrigin=0.0,
>  xgOrigin=99.,
>  dxSpacing=0.1,
>  dySpacing=0.1,
>  delR=10.,10.,15.,15.,20.,30.,50.,70.,80.,100.,
>  150.,150.,200.,300.,400.,500.,600.,700.,800.,800.,
>  &
> 
> # Input datasets
>  &PARM05
>  bathyFile='topog.bin',
>  zonalWindFile='tx.bin'
>  meridWindFile='ty.bin'
>  uVelInitFile='Uvel.bin',
>  vVelInitFile='Vvel.bin',
>  hydrogThetaFile='Temp.bin',
>  hydrogSaltFile='Salt.bin',
>  &
> 
> data.obcs:
> # Open-boundaries
>  &OBCS_PARM01
> # This flag turns off checking and fixing problematic topography
> across
> # open boundaries.
>  OBCSfixTopo=.FALSE.,
>  OB_Jnorth= 350*-1,
>  OB_Jsouth= 350*1,
>  OB_Ieast = 300*-1,
> 
>  useOBCSprescribe = .TRUE.,
>  useOrlanskiNorth = .TRUE.,
>  useOrlanskiSouth = .TRUE.,
>  useOrlanskiEast = .TRUE.,
> 
>  OBNuFile = 'OB_NorthU.bin',
>  OBSuFile = 'OB_SouthU.bin',
>  OBEuFile = 'OB_EastU.bin',
>  OBNvFile = 'OB_NorthV.bin',
>  OBSvFile = 'OB_SouthV.bin',
>  OBEvFile = 'OB_EastV.bin',
> 
>  OBCS_monitorFreq= 1200.,
>  OBCS_monSelect = 1,
>  &
> 
> # Orlanski parameters
>  &OBCS_PARM02
> #Cmax=0.45,
> #cVelTimeScale=1000.,
>  &
> 
> data.exf:
> # *********************
> # External Forcing Data
> # *********************
>  &EXF_NML_01
>  repeatPeriod= 31104000.,
>  readStressOnCgrid = .TRUE.,
>  useAtmWInd = .FALSE.,
>  exf_iprec = 64,
>  &
> 
> # *********************
>  &EXF_NML_02
>  ustressstartdate1 = 20090101,
>  ustressstartdate2 = 000000,
>  ustressperiod = 2592000.0,
> #
>  vstressstartdate1 = 20090101,
>  vstressstartdate2 = 000000,
>  vstressperiod = 2592000.0,
> #
>  climsststartdate1 = 20090101,
>  climsststartdate2 = 000000,
>  climsstperiod = 2592000.0,
> # 2 months restoring timescale for temperature
>  climsstTauRelax = 5184000.,
> #
>  climsssstartdate1 = 20090101,
>  climsssstartdate2 = 000000,
>  climsssperiod = 2592000.0,
> # 6 months restoring timescale for salinity
>  climsssTauRelax = 15552000.,
> #
>  ustressfile = 'tx.bin',
>  vstressfile = 'ty.bin',
>  climsstfile = 'CliT.bin',
>  climsssfile = 'CliS.bin',
> #
>  &
> 
> # *********************
>  &EXF_NML_03
>  &
> 
> # *********************
>  &EXF_NML_04
> 
>  climsst_lon0 = 99.05,
>  climsst_lon_inc = 0.1,
>  climsst_lat0 = 0.05,
>  climsst_lat_inc = 0.1,
>  climsst_nlon = 350,
>  climsst_nlat = 300,
> 
>  climsss_lon0 = 99.05,
>  climsss_lon_inc = 0.1,
>  climsss_lat0 = 0.05,
>  climsss_lat_inc = 0.1,
>  climsss_nlon = 350,
>  climsss_nlat = 300,
> 
>  &
> &EXF_NML_OBCS
>  obcsEstartdate1 = 20090101,
>  obcsEstartdate2 = 00000,
>  obcsEperiod = 2592000,
> #
>  obcsNstartdate1 = 20090101,
>  obcsNstartdate2 = 000000,
>  obcsNperiod = 2592000,
> #
>  obcsSstartdate1 = 20090101,
>  obcsSstartdate2 = 000000,
>  obcsSperiod = 2592000,
>  &
> 
> 
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