[MITgcm-support] Large runoff causes negative salinity

Jean-Michel Campin jmc at mit.edu
Sun Jun 19 17:58:16 EDT 2016


Hi Mattia,

You may want to try to set:
 useRealFreshWaterFlux=.TRUE.,
in main parameter file "data", namelist: PARM01
This would remove the need to convert surface fresh-water into a salt-flux
(more realistic, specially since you are using non-linear free-surf).

But if you don't want to switch on RealFreshWaterFlux, you could
still try to set: 
 convertFW2Salt=-1., (again, same file & namelist)
so that the conversion will use the local salinity (instead of a constant value)

Cheers,
Jean-Michel

On Sun, Jun 19, 2016 at 02:56:25PM -0400, Mattia Almansi wrote:
> Hi Ryan,
> 
> I'm currently using the advection scheme 33.
> Attached are my data and data.exf files.
> 
> Thanks,
> Mattia
> 
> 
> 
>    - Here is the contents of the data file attached:
> 
> #
> # ******************************
> # Model parameters
> # Continuous equation parameters
> # ******************************
>  &PARM01
>  viscAz =1.E-5,
>  diffK4T=0.0,
>  diffKzT=1.E-5,
>  diffK4S=0.0,
>  diffKzS=1.E-5,
>  viscAhGridMax=0.25,
>  viscC2Leith=0.0,
>  viscAhGrid=0.0,
>  useAnisotropicViscAGridMax=.TRUE.,
>  viscA4GridMax=0.25,
>  viscC4Leith=1.0,
>  viscA4Grid=0.0,
>  no_slip_sides=.TRUE.,
>  no_slip_bottom=.TRUE.,
>  bottomDragQuadratic = 0.001,
>  rigidLid=.FALSE.,
>  implicitFreeSurface=.TRUE.,
> #--- z* - begin
>  nonlinFreeSurf    = 4,
>  exactConserv      = .TRUE.,
>  select_rStar      = 2,
>  hFacInf           = 0.01,
>  hFacSup           = 2.5,
> #--- z* - end
> #--- - debugMode in eedata
>  debugLevel          = 3,
>  eosType='JMD95Z',
>  readBinaryPrec=64,
>  writeBinaryPrec=64,
>  useSingleCpuIo=.TRUE.,
>  globalFiles=.TRUE.,
>  hFacMin=0.1,
>  hFacMinDz=5.,
>  allowFreezing=.FALSE.,
>  HeatCapacity_Cp = 3986.D0,
>  gravity         = 9.8156,
>  gBaro           = 9.8156,
>  rhoNil          = 1027.D0,
>  implicitDiffusion=.TRUE.,
>  implicitViscosity=.TRUE.,
>  vectorInvariantMomentum=.TRUE.,
>  staggerTimeStep=.TRUE.,
>  tempAdvScheme=33,
>  saltAdvScheme=33,
>  MultiDimAdvection=.TRUE.,
>  &
> 
> # **************************
> # Elliptic solver parameters
> # **************************
>  &PARM02
>  cg2dMaxIters=1000,
>  cg2dTargetResidual=1.E-13,
>  &
> 
> # ************************
> # Time stepping parameters
> # ************************
>  &PARM03
>   nIter0=0,
>   endTime=259200.0,
>   deltaT=30.0,
>   tauCD=0.,
>   cAdjFreq=0.,
>   abEps=0.1,
>   forcing_In_AB=.FALSE.,
>   chkptFreq=604800.,
>   pChkptFreq=864000.0,
>   dumpFreq=21600.,
>   diagFreq=0.,
>   monitorFreq=3600.,
>  &
> 
> # *******************
> # Gridding parameters
> # *******************
>  &PARM04
>  usingCartesianGrid=.FALSE.,
>  usingSphericalPolarGrid=.TRUE.,
>  delZ= 2,   3,   4,   5,   6,   7,   8,   9,  10,  11, 12,
>       13,  14,  203*15,
>  ygOrigin=+56.79340,
>  xgOrigin=-46.95949,
>  delY= [see attached file]
>  delX= [see attached file]
>  rSphere         = 6371.D3,
>  &
> # **********
> # Data Files
> # **********
>  &PARM05
>  bathyFile='Bat_irm2kmGlacAuto.bin',
>  hydrogThetaFile='Temp_Initial_irm2kmGlacAuto.bin',
>  hydrogSaltFile='Salt_Initial_irm2kmGlacAuto.bin',
>  uVelInitFile='Uvel_Initial_irm2kmGlacAuto.bin',
>  vVelInitFile='Vvel_Initial_irm2kmGlacAuto.bin',
>  pSurfInitFile='Eta_Initial_irm2kmGlacAuto.bin',
> # set to false to avoid checking for theta=0 and salt=0 when we start with
> sea ice temp and salt
>  checkIniTemp=.TRUE.,
>  checkIniSalt=.TRUE.,
>  &
> 
> # Open boundaries
>  &PARM06
>  &
> 
> # KPP Mixing scheme
>  &PARM07
>  &
> 
> 
> 
> 
>    - Here is the contents of the data.exf file attached:
> 
> #
> # *********************
> # External Forcing Data
> # *********************
>  &EXF_NML_01
> #
>  useExfCheckRange  = .TRUE.,
>  exf_iprec         = 64,
>  exf_yftype        = 'RL',
>  &
> #
> # *********************
>  &EXF_NML_02
> # format
> # startdate1=YYYYMMDD
> # startdate2=HHMMSS
> # *********************
> #
>  atempstartdate1 = 20061231,
>  atempstartdate2 = 000000,
>  atempperiod = 10800.0,
> #
>  aqhstartdate1 = 20061231,
>  aqhstartdate2 = 000000,
>  aqhperiod = 10800.0,
> #
>  evapstartdate1 = 20061231,
>  evapstartdate2 = 013000,
>  evapperiod = 10800.0,
> #
>  precipstartdate1 = 20061231,
>  precipstartdate2 = 013000,
>  precipperiod = 10800.0,
> #
>  uwindstartdate1 = 20061231,
>  uwindstartdate2 = 000000,
>  uwindperiod = 10800.0,
> #
>  vwindstartdate1 = 20061231,
>  vwindstartdate2 = 000000,
>  vwindperiod = 10800.0,
> #
> # swfluxstartdate1 = 20061231,
> # swfluxstartdate2 = 013000,
> # swfluxperiod = 10800.0,
> #
> # lwfluxstartdate1 = 20061231,
> # lwfluxstartdate2 = 013000,
> # lwfluxperiod = 10800.0,
> #
>  swdownstartdate1 = 20061231,
>  swdownstartdate2 = 013000,
>  swdownperiod = 10800.0,
> #
>  lwdownstartdate1 = 20061231,
>  lwdownstartdate2 = 013000,
>  lwdownperiod = 10800.0,
> #
>  climsststartdate1 = 20061231,
>  climsststartdate2 = 120000,
>  climsstperiod = 86400.0,
> # restoring timescale for sea sur. temperature
>  climsstTauRelax = 86400.0,
> #
>  runoffstartdate1 = 20061231,
>  runoffstartdate2 = 000000,
>  runoffperiod = 86400.0,
> #
>  atempfile = 'atemp_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  aqhfile = 'sphum_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  uwindfile = 'uwind_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  vwindfile = 'vwind_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  evapfile = 'evapr_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  precipfile = 'preci_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
> # lwfluxfile = 'nlwfl_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
> # swfluxfile = 'nswfl_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  lwdownfile = 'dlwfl_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  swdownfile = 'dswfl_EraInterim3h_irm2kmGlacAuto_20061231_20070112.bin',
>  climsstfile = 'OstiaDailySst_irm2kmGlacAuto_20061231_20070112.bin',
>  runoffFile = 'runoff_Glacier_irm2kmGlacAuto_20061231_20070112.bin',
>  runoftempFile = 'runoftemp_Glacier_irm2kmGlacAuto_20061231_20070112.bin',
>  &
> #
> # *********************
>  &EXF_NML_03
>  &
> #
> # *********************
>  &EXF_NML_04
>  &
> #
> # *********************
>  &EXF_NML_OBCS
>  obcsNstartdate1 = 20061231,
>  obcsNstartdate2 = 000000,
>  obcsNperiod = 86400.0,
> #
>  obcsSstartdate1 = 20061231,
>  obcsSstartdate2 = 000000,
>  obcsSperiod = 86400.0,
> #
>  obcsEstartdate1 = 20061231,
>  obcsEstartdate2 = 000000,
>  obcsEperiod = 86400.0,
> #
>  obcsWstartdate1 = 20061231,
>  obcsWstartdate2 = 000000,
>  obcsWperiod = 86400.0,
> #
> ##### SEA ICE OBCS
> #
>  siobNstartdate1 = 20061215,
>  siobNstartdate2 = 000000,
>  siobNperiod = 2635200.0,
> #
>  siobSstartdate1 = 20061215,
>  siobSstartdate2 = 000000,
>  siobSperiod = 2635200.0,
> #
>  siobEstartdate1 = 20061215,
>  siobEstartdate2 = 000000,
>  siobEperiod = 2635200.0,
> #
>  siobWstartdate1 = 20061215,
>  siobWstartdate2 = 000000,
>  siobWperiod = 2635200.0,
>  &
> 
> 2016-06-19 13:18 GMT-04:00 Ryan Abernathey <ryan.abernathey at gmail.com>:
> 
> > Hi Mattia,
> >
> > This could be related to your advection scheme. Please provide your full
> > data and data.exf files in order to help people diagnose the problem.
> >
> > -Ryan
> >
> > On Sun, Jun 19, 2016 at 1:02 PM, Mattia Almansi <mattia.almansi at jhu.edu>
> > wrote:
> >
> >> Dear all,
> >>
> >> I'm setting up a configuration which includes part of Greenland's East
> >> coast.
> >> I'm having some issues with the runoff: the salinity output field is
> >> negative where the runoff is large. There are some large runoff values
> >> (e.g. 1.e-4 m/s into the fjords) because I want to include both glacier
> >> runoff and solid ice discharge.
> >> Is there any way to avoid this problem?
> >>
> >> Thanks in advance,
> >> Mattia
> >>
> >> --
> >> Mattia Almansi,
> >> Ph.D. Student,
> >> Johns Hopkins University,
> >> Department of Earth and Planetary Sciences,
> >> 315 Olin Hall - 3400 N. Charles Street, Baltimore, MD 21218
> >>
> >> e-mail: mattia.almansi at jhu.edu
> >>
> >> _______________________________________________
> >> MITgcm-support mailing list
> >> MITgcm-support at mitgcm.org
> >> http://mitgcm.org/mailman/listinfo/mitgcm-support
> >>
> >>
> >
> > _______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-support
> >
> >
> 
> 
> -- 
> Mattia Almansi,
> Ph.D. Student,
> Johns Hopkins University,
> Department of Earth and Planetary Sciences,
> 315 Olin Hall - 3400 N. Charles Street, Baltimore, MD 21218
> 
> e-mail: mattia.almansi at jhu.edu



> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-support




More information about the MITgcm-support mailing list