[MITgcm-support] SST problem when restarting a run

Martin Losch Martin.Losch at awi.de
Tue Feb 11 09:42:09 EST 2020


Hi Fei,

your nIter0 suggests 1569600*3600 seconds ~ 179 years, not 50 years.

Did you change the time step? In that case the model gets confused about the actual time and phase errors may occur.

Martin

> On 2. Feb 2020, at 04:11, pan fei <feiamanda at hotmail.com> wrote:
> 
> Hi everyone,
> I used climatological taux, tauy and net heat flux to spin up the MITgcm model for 50 years, the simulated SST, ocean temperature and ocean currents are OK. Then I restart the run at the 50th year (using the same atmospheric forcing) . Strangely, the SST change  a lot : the SST decrease rapidly everywhere and there are large SST values centering on the equator (the SST pattern seems like the SST pattern at the beginning of the cold start) , but the ocean current looks OK (which is similar with the current of the 49th year). I was wondering if anyone can help me with this problem.
> Thank you so much.
> Best,
> Fei
>  
> Following are the data and data.exf files:
> %%%%%%%%%%%%%%%data file:
> # ====================
> # | Model parameters |
> # ====================
> #
> # Continuous equation parameters
> &PARM01
> tRef               = 3*23.,3*22.,21.,2*20.,19.,2*18.,17.,2*16.,15.,14.,13.,
>                       12.,11.,2*9.,8.,7.,2*6.,2*5.,3*4.,3*3.,4*2.,12*1.,
> sRef               = 50*34.5,
> no_slip_sides  = .TRUE.,
> no_slip_bottom = .TRUE.,
> #
> viscAr=0.5E-4,
> #
> viscAh=1.E0,
> viscAhGrid=2.E-2,
> # viscAh=2.0e4,
> #
> diffKhT=1.E1,
> diffKrT=1.E-5,
> diffKhS=1.E1,
> diffKrS=1.E-5,
> #
> ### diffKrBL79surf=0.1E-4,
> ### diffKrBL79deep=1.0E-4,
> bottomDragQuadratic = 0.001,
> #when using ggl90
> ivdc_kappa=10.,
> implicitDiffusion=.TRUE.,
> implicitViscosity=.TRUE.,
> useRealFreshWaterFlux=.TRUE.,
> # balanceThetaClimRelax=.TRUE.,
> balanceSaltClimRelax=.TRUE.,
> # balanceEmPmR=.TRUE.,
> # balanceQnet=.TRUE.,
> allowFreezing=.FALSE.,
> ### hFacInf=0.2,
> ### hFacSup=2.0,
> hFacMin=.2,
> hFacMinDr=5.,
> select_rStar=2,
> nonlinFreeSurf=4,
> gravity=9.81,
> rhonil=1029.,
> rhoConst=1029.,
> rhoConstFresh=1000.,
> convertFW2Salt=-1.,
> eosType='JMD95Z',
> implicitFreeSurface=.TRUE.,
> exactConserv=.TRUE.,
> useSingleCpuIO=.TRUE.,
> tempAdvScheme=30,
> saltAdvScheme=30,
> tempVertAdvScheme=3,
> saltVertAdvScheme=3,
> tempImplVertAdv=.TRUE.,
> saltImplVertAdv=.TRUE.,
> staggerTimeStep=.TRUE.,
> vectorInvariantMomentum=.TRUE.,
> #when using the cd scheme:
> # useCDscheme=.TRUE.,
> useJamartWetPoints=.TRUE.,
> readBinaryPrec=32,
> writeBinaryPrec=32,
> debugLevel=1,
> /
>  
> # Elliptic solver parameters
> &PARM02
> cg2dMaxIters=300,
> #cg2dTargetResWunit=1.E-12,
> /
>  
> # Time stepping parameters
> &PARM03
> nIter0=1569600,
> #2 lev2 for testing:
> #nTimeSteps=8,
> #3month
> #nTimeSteps=350000,
> #18month
> #nTimeSteps=13110,
> #2yr
> #nTimeSteps=17520,
> #4-yr from 2014 to 2017, inclusive
> #nTimeSteps=35051,
> #20y:
> #nTimeSteps=175295,
> #22y:
> #nTimeSteps=192839,
> #24y:
> #nTimeSteps=210359,
> #26yr 
> #nTimeSteps=227903,
> #60 years
> nTimeSteps=527040,
> #
> forcing_In_AB=.FALSE.,
> momDissip_In_AB=.FALSE.,
> #when using the cd scheme:
> # epsAB_CD = 0.25,
> # tauCD=172800.0,
> deltaTmom   =3600.,
> deltaTtracer=3600.,
> deltaTfreesurf=3600.,
> deltaTClock =3600.,
> #when using ab2:
> # abEps = 0.1,
> #when using ab3:
> doAB_onGtGs=.FALSE.,
> alph_AB=0.5,
> beta_AB=0.281105,
> #
> pChkptFreq  =10368000.0,
> chkptFreq   =10368000.0,
> # taveFreq    =2635200.0,
> # dumpFreq    =2635200.0,
> # monitorFreq = 7200.0,
> monitorFreq = 2592000.0,
> dumpInitAndLast = .TRUE.,
> adjDumpFreq = 31536000.0,
> #adjDumpFreq = 604800.0,
> adjMonitorFreq = 864000.0,
> pickupStrictlyMatch=.FALSE.,
> /
>  
> # Gridding parameters
> &PARM04
> usingCurvilinearGrid=.TRUE.,
> delR = 
>      10.00, 10.00, 10.00, 10.00, 10.00, 10.00, 10.00, 10.01,
>      10.03, 10.11, 10.32, 10.80, 11.76, 13.42, 16.04, 19.82, 24.85,
>      31.10, 38.42, 46.50, 55.00, 63.50, 71.58, 78.90, 85.15, 90.18,
>      93.96, 96.58, 98.25, 99.25,100.01,101.33,104.56,111.33,122.83,
>      139.09,158.94,180.83,203.55,226.50,249.50,272.50,295.50,318.50,
>      341.50,364.50,387.50,410.50,433.50,456.50,
> /
>  
> # Input datasets
> &PARM05
> diffKrFile='total_diffkr_r009bit11.bin',
> adTapeDir='tapes',
> #bathyFile      ='bathy_eccollc_90x50.bin',
> bathyFile      ='bathy_eccollc_90x50_min2pts.bin',
> hydrogThetaFile='T_OWPv1_M_eccollc_90x50.bin',
> hydrogSaltFile ='S_OWPv1_M_eccollc_90x50.bin',
> viscA4Dfile    ='fenty_biharmonic_visc_v11.bin',
> viscA4Zfile    ='fenty_biharmonic_visc_v11.bin',
> geothermalFile='geothermalFlux.bin',
> #
> /
>  
>  
> %%%%%%%%%%data.exf
> # *********************
> # External Forcing Data
> # *********************
> #
> &EXF_NML_01
> #
> # useAtmWind        = .FALSE.,
> #NCEP VALUES:
> # exf_albedo        = 0.15,
> # exf_scal_BulkCdn  = 1.015,
> #
> #TO COMBINE WITH ALLOW_ZENITH_ANGLE:
> # exf_albedo        = 0.1,
> #
> # ocean_emissivity = 0.97,
> # ice_emissivity = 0.95,
> # snow_emissivity = 0.95,
> #
> exf_iprec         = 32,
> exf_yftype        = 'RL',
> useExfYearlyFields= .FALSE.,
> useExfCheckRange  = .FALSE.,
> readStressOnAgrid = .TRUE.,
> rotateStressOnAgrid = .TRUE.,
> repeatPeriod      =31104000,
> /
> #
> &EXF_NML_02
> hfluxfile         = 'eccov4r4diags_hflux_monthly',
> # sfluxfile         = 'eccov4r4diags_sflux_monthly',
> ustressfile       = 'eccov4r4diags_taux_monthly',
> vstressfile       = 'eccov4r4diags_tauy_monthly',
> swfluxfile        = 'eccov4r4diags_shortwavenet_monthly',
> # runofffile        = 'era5_runoffclim',
> climsstfile       = 'SSTquater.bin',
> climsssfile       = 'SSSquater.bin',
> #
> hfluxstartdate1   = 19790101,
> hfluxstartdate2   = 000000,
> hfluxperiod       = 2592000.0,
> #
> sfluxstartdate1   = 19790101,
> sfluxstartdate2   = 000000,
> sfluxperiod       = 2592000.0,
> #
> ustressstartdate1 = 19790101,
> ustressstartdate2 = 000000,
> ustressperiod     = 2592000.0,
> #
> vstressstartdate1 = 19790101,
> vstressstartdate2 = 000000,
> vstressperiod     = 2592000.0,
> #
> swfluxstartdate1  = 19790101,
> swfluxstartdate2  = 000000,
> swfluxperiod      = 2592000.0,
> #
> runoffstartdate1  = 19790101,
> runoffstartdate2  = 000000,
> runoffperiod      = 2592000.0,
> #
> climsststartdate1 = 19790101,
> climsststartdate2 = 000000,
> climsstperiod     = 2592000.0,
> climsstTauRelax   = 39744000.0,
> #
> # climsssperiod      = -12.0,
> climsssstartdate1 = 19790101,
> climsssstartdate2 = 000000,
> climsssperiod     = 2592000.0,
> climsssTauRelax    = 1296000.0,
> &
> #
> &EXF_NML_03
> exf_inscal_ustress= -1.,
> exf_inscal_vstress= -1.,
> # exf_inscal_runoff = 3.1710e-08,
> &
> #
> &EXF_NML_04
> ustress_interpMethod = 0,
> vstress_interpMethod = 0,
> hflux_interpMethod = 0,
> # swdown_interpMethod = 0,
> sflux_interpMethod = 0,
> swflux_interpMethod = 0,
> #
> # runoff_lon0        = 0.0D0,
> # runoff_lon_inc     =   0.7031250D0,
> # runoff_lat0        = -89.4628220D0,
> # runoff_lat_inc     = 0.6958694,0.6999817,0.7009048,0.7012634,0.7014313,
> #                     245*0.7017418,
> #                     0.7014313,0.7012634,0.7009048,0.6999817,0.6958694
> # runoff_nlon        = 512,
> # runoff_nlat        = 256,
> #
> climsst_lon0       = 0.0D0,
> climsst_lon_inc    =   0.7031250D0,
> climsst_lat0       = -89.4628220D0,
> climsst_lat_inc    = 0.6958694,0.6999817,0.7009048,0.7012634,0.7014313,
>                      245*0.7017418,
>                      0.7014313,0.7012634,0.7009048,0.6999817,0.6958694
> climsst_nlon       = 512,
> climsst_nlat       = 256,
> #
> climsss_lon0       = 0.0D0,
> climsss_lon_inc    =   0.7031250D0,
> climsss_lat0       = -89.4628220D0,
> climsss_lat_inc    = 0.6958694,0.6999817,0.7009048,0.7012634,0.7014313,
>                      245*0.7017418,
>                      0.7014313,0.7012634,0.7009048,0.6999817,0.6958694
> climsss_nlon       = 512,
> climsss_nlat       = 256,
> &
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