[MITgcm-support] Warning and time stepping issue

[Anthony Coletti]

I should be more specific with my problem.  Apologies.

See below for the original problem:

I am using the sea-ice package and external forcing packages (along with other default packages) to do a control LGM simulation of the Arctic.  I am currently trying to see how much sea ice I can grow in the Arctic during this period.  I have prescribed most of the atmosphere, the initial SST and Salinity fields.

My data file looks like this:

# ====================
# | Model parameters |
# ====================
#
# Continuous equation parameters
 &PARM01
 tRef=15*20.,
 sRef=15*35.,
 viscAh =3.E5,
 viscAr =1.E-3,
 diffKhT=0.,
 diffK4T=0.,
 diffKrT=3.E-5,
 diffKhS=0.,
 diffK4S=0.,
 diffKrS=3.E-5,
 ivdc_kappa=10.,
 implicitDiffusion=.TRUE.,
 gravity=9.81,
 rhoConst=1035.,
 rhoConstFresh=1000.,
 eosType='JMD95Z',
 staggerTimeStep=.TRUE.,
 vectorInvariantMomentum=.TRUE.,
 implicitFreeSurface=.TRUE.,
 exactConserv=.TRUE.,
 select_rStar=2,
 nonlinFreeSurf=4,
 hFacInf=0.2,
 hFacSup=2.0,
 useRealFreshWaterFlux=.TRUE.,
 hFacMin=.1,
 hFacMinDr=20.,
#- to check that it has no impact:
# doResetHFactors=.TRUE.,
# tempAdvScheme=7,
# saltAdvScheme=7,
 readBinaryPrec=32,
 writeBinaryPrec=32,
 useSingleCpuIO=.TRUE.,
 &

# Elliptic solver parameters
 &PARM02
 cg2dMaxIters=200,
#cg2dTargetResidual=1.E-9,
 cg2dTargetResWunit=1.E-14,
 &

# Time stepping parameters
 &PARM03
 nIter0=0.,
 endTime=31557600000.,
 deltaT= 1500.,
 abEps = 0.1,
 forcing_In_AB=.FALSE.,
 pickupStrictlyMatch=.FALSE.,
 cAdjFreq=0.,
 pChkptFreq   = 31557600.,
 chkptFreq    = 15778800.,
 monitorFreq = 21600.,
 &

# Gridding parameters
 &PARM04
 usingCurvilinearGrid=.TRUE.,
 horizGridFile='../../../input.files/grid_inputs/grid_cs32',
 delR= 50., 70., 100., 140., 190.,
       240., 290., 340., 390., 440.,
       490., 540., 590., 640., 690.,
 &

# Input datasets
 &PARM05
 bathyFile      ='../../../input.files/LGM_cntr/lgm+ish_cntr_bathy.bin',
 hydrogThetaFile='../../../input.files/LGM_cntr/sfc_T_coldstart_32x32x15.bin',
 hydrogSaltFile ='../../../input.files/LGM_cntr/oce_salt_coldstart_32x32x15.bin',
 &


When I lower my time step BELOW 5000. s, it does not crash and is stable the entire run.  I also have bathymetry set to LGM levels (adding 120m to the bathymetry files) to make the ocean more shallow.


Anthony


Anthony J. Coletti
Climate System Research Center
Department of Geosciences
Morrill Building
611 N. Pleasant Street
233 Morrill Science Center
University of Massachusetts-Amherst
paleoclimate.org
Email: ajcolett at geo.umass.edu
http://blogs.umass.edu/ajcolett/

“For me, I am driven by two main philosophies: know more today about the world than I knew yesterday and lessen the  suffering of others. You'd be surprised how far that gets you.” ― Neil deGrasse Tyson




On Jan 16, 2014, at 9:45 AM, Anthony Coletti <ajcolett at geo.umass.edu> wrote:

> Hi all,
> 
> I am trying to run a course 32x32x15 (6 faces) run to get some preliminary data.  Unfortunately, my time step will not exceed 5000.s.  ~ Two minutes into the run, it crashes and I get the corresponding error::
> 
> WARNING: r*FacC > hFacSup at       1 pts : bi,bj,Thid,Iter=   4   1   1       106
>  e.g. at i,j=   2   1 ; rStarFac,H,eta =  2.028435  2.200000E+01  2.262556E+01
> WARNING: r*FacC > hFacSup at       1 pts : bi,bj,Thid,Iter=   4   1   1       107
>  e.g. at i,j=   2   1 ; rStarFac,H,eta =  2.333596  2.200000E+01  2.933912E+01
> WARNING: r*FacW < hFacInf at       2 pts : bi,bj,Thid,Iter=   2   1   1       108
>  e.g. at i,j=   5   2 ; rStarFac,H,eta =  0.094709  1.368000E+03 -6.740896E+02 -1.803211E+03
> STOP in CALC_R_STAR : too SMALL rStarFacW !
> WARNING: r*FacS < hFacInf at       1 pts : bi,bj,Thid,Iter=   2   1   1       108
>  e.g. at i,j=   3   2 ; rStarFac,H,eta = -0.186928  2.400000E+02  5.703576E+01 -6.277609E+02
> STOP in CALC_R_STAR : too SMALL rStarFacS !
> WARNING: r*FacC < hFacInf at       2 pts : bi,bj,Thid,Iter=   2   1   1       108
>  e.g. at i,j=   5   2 ; rStarFac,H,eta = -0.152948  1.564000E+03 -1.803211E+03
> STOP in CALC_R_STAR : too SMALL rStarFacC !
> 
> If you need any other info, please let me know.  Any help would be appreciated!
> 
> 
> Thanks!
> 
> Anthony
> 
> Anthony J. Coletti
> Climate System Research Center
> Department of Geosciences
> Morrill Building
> 611 N. Pleasant Street
> 233 Morrill Science Center
> University of Massachusetts-Amherst
> paleoclimate.org
> Email: ajcolett at geo.umass.edu
> http://blogs.umass.edu/ajcolett/
> 
> “For me, I am driven by two main philosophies: know more today about the world than I knew yesterday and lessen the  suffering of others. You'd be surprised how far that gets you.” ― Neil deGrasse Tyson
> 
> 
> 
> 

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