[MITgcm-support] 2D boundary conditions at the poles
Jean-Michel Campin
jmc at ocean.mit.edu
Sat Nov 12 22:57:56 EST 2011
Hi Angela,
I would propose to try to use Shap_funct=2 (this is the default)
instead of Shap_funct=4.
In addition, you could try to specify a time-scale (the default
is to use the model time-step), the longer it is, the weaker
is the filtering. You could start for example with 10 times deltaT:
Shap_Trtau=150.,
Shap_uvtau=150.,
(since deltaT=15.)
Cheers,
Jean-Michel
On Sat, Nov 12, 2011 at 11:47:53AM -0500, Angela Marie Zalucha wrote:
> A figure of surface pressure (eta + Ro_SeaLevel) vs. latitude is
> attached. My data file is below.
>
> # ====================
> # | Model parameters |
> # ====================
> #
> # Continuous equation parameters
> &PARM01
> tref=48.2417,48.388,48.6109,48.9495,49.4687,50.2756,51.5217,53.239,
> 55.3375,57.8211,60.7092,64.0167,67.7569,71.9439,76.5962,81.74,
> 87.413,93.6712,100.6,108.332,117.086,127.225,139.377,154.64,
> 174.981,203.995,248.46,321.723,453.693,746.463,
> sRef=30*0.,
> #viscAr=0.E1,
> viscAh=0.E6,
> viscA4=0.E17,
> no_slip_sides=.FALSE.,
> no_slip_bottom=.FALSE.,
> diffKhT=0.E3,
> diffKrT=0.,
> diffK4T=0.E17,
> diffKrS=0.E2,
> diffKhS=0.E3,
> diffK4S=0.E17,
> buoyancyRelation='ATMOSPHERIC',
> eosType='IDEALGAS',
> omega=-1.13856E-5,
> exactConserv=.TRUE.,
> gravity=0.63,
> rhonil=1.0,
> rhoConst=1.0,
> rigidLid=.FALSE.,
> uniformLin_PhiSurf=.FALSE.,
> nonlinFreeSurf=4,
> select_rStar=2,
> implicitFreeSurface=.TRUE.,
> staggerTimeStep=.TRUE.,
> readBinaryPrec=64,
> writeBinaryPrec=64,
> hFacMin=1.0,
> # vectorInvariantMomentum=.TRUE.,
> #- not safe to use globalFiles in multi-processors runs; set instead useSingleCpuIO
> useSingleCpuIO=.TRUE.,
> atm_Cp = 1043.,
> atm_Po = 1.4,
> atm_Cp = 1043.,
> atm_Po = 1.4,
> atm_kappa=0.2857142885714,
> atm_L=253000.,
> lengthOfDayInSeconds=551893.,
> # Buie, tholen, and wasserman 1997 albedo
> # albedoland = 0.5,
> # albedoice = 0.5,
> albedoland=0.,
> albedoice=0.,
> radcode = 6,
> lsIsConstant = 0,
> lsperpetual = 3.141593,
> eccentricity = 0.251,
> semimajoraxis = 5.934632E12,
> lsp = 3.24383404117,
> axialTilt = 1.05434,
> solarconstant = 0.864465,
> tauoo = 2.,
> # radTimeStep = 21600.,
> radTimeStep = 15.,
> lsStart = 2.5688,
> hstauawarm=22075.7,
> hstauswarm=22075.7,
> hstauacold=22075.7,
> hstauscold=22075.7,
> emissivityOfIce=1.0,
> emissivityOfLand=1.0,
> allowDiurnal=0,
> betacab=0.05,
> tauinfcab=0.1,
> useCaballero=0,
> referenceTempInFrostEqn=35.,
> referencePresInFrostEqn=0.3,
> initemp=110.,
> gamma0=0.01,
> &
>
> # Elliptic solver parameters
> &PARM02
> cg2dMaxIters=600,
> cg2dTargetResidual=1.E-13,
> &
>
> # Time stepping parameters
> &PARM03
> niter0=0,
> # nTimeSteps=31104000,
> # nTimeSteps=69465600,
> nTimeSteps=71539200,
> #endTime=864000.0,
> abEps=0.1,
> deltaT=15.,
> cAdjFreq=0.,
> pChkptFreq=466560000.,
> chkptFreq=0.0,
> dumpFreq=7776000.,
> # dumpFreq=2000.,
> # dumpFreq=518400.,
> #dumpFreqFast=39750.,
> #dumpFreqFastStart=5326500.,
> monitorFreq=7776000.,
> # monitorFreq=2000.
> # monitorFreq=50.,
> taveFreq=0.,
> #tave_lastiter=1.,
> #tave_lastiter=1.,
> &
>
> # Gridding parameters
> &PARM04
> usingSphericalPolarGrid=.TRUE.,
> delX=1*2.8125,
> delY=64*2.8125,
> delR=0.0244849394,0.0364268333,0.0525751970,0.0746640152,0.1034712424,
> 0.1382839394,0.1679554545,0.1557584848,0.1340775758,0.1112777273,
> 0.0898157273,0.0711273182,0.0555934697,0.0431052576,0.0332630455,
> 0.0256038788,0.0196925909,0.0151563788,0.0116906364,0.0090528773,
> 0.0070505591,0.0055292258,0.0043596742,0.0034272000,0.0026279697,
> 0.0018837212,0.0011799030,0.0005905985,0.0002190777,0.0000554814,
> Ro_SeaLevel=1.4,
> # don't change rSphere, because tiles are calculated using this number
> rSphere=1180.E3,
> ygOrigin=-90.,
> &
>
> # Input datasets
> &PARM05
> topoFile='topo.cs.bin',
> # topoTextFile='plutotopo.txt',
> &
>
>
>
>
>
> On Sat, 12 Nov 2011, Jean-Michel Campin wrote:
>
> >Hi Angela,
> >
> >Could you send the complete parameter file "data" ? might be useful
> >to figure out what is the problem. Also, a plot of Eta function
> >of latitude would be nice.
> >
> >Cheers,
> >Jean-Michel
> >
> >On Thu, Nov 10, 2011 at 06:34:34PM -0500, Angela Marie Zalucha wrote:
> >>Hi,
> >>
> >>I am running the MIT GCM in 2D for the atmosphere (latitue and r*
> >>coordinates). When I look at eta vs. latitue, I get a very huge
> >>spike in the second to last gridpoint from the poles. I believe it
> >>is numerical and not physical. I was wondering what the boundary
> >>conditions are at the poles and how to explain it.
> >>
> >>Here's what I have for the horizontal grid:
> >>usingSphericalPolarGrid=.TRUE.,
> >> delX=1*2.8125,
> >> delY=64*2.8125,
> >> ygOrigin=-90.,
> >>
> >>The pressure is extremely low because this is Pluto!
> >>Ro_SeaLevel=1.6,
> >>rSphere=1180.E3,
> >>
> >>I have seen that the Shapiro filter can affect numerical spikes in
> >>eta in other 2D planets, but haven't been able to modify it
> >>successfully here. Here's my data.shap :
> >> &SHAP_PARM01
> >> shap_filt_uvStar=.FALSE.,
> >> shap_filt_TrStagg=.TRUE.,
> >> Shap_funct=4,
> >> nShapT=4,
> >> nShapUV=4,
> >>
> >>Does anybody have any ideas?
> >>
> >> Angela
> >>
> >>
> >>
> >>_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
> >>Angela Zalucha, Ph.D.
> >>Postdoctoral Associate
> >>Department of Earth, Atmospheric,
> >> and Planetary Sciences
> >>Massachusetts Institute of Technology
> >>
> >>Office located at Southwest Research Institute
> >>1050 Walnut Street, Suite 300
> >>Boulder, CO 80302
> >>USA
> >>(720) 208-7211
> >>
> >>
> >>http://web.mit.edu/azalucha/www/index.html
> >>_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
> >>
> >>
> >>
> >>
> >>_______________________________________________
> >>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
> >
>
> _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
> Angela Zalucha, Ph.D.
> Postdoctoral Associate
> Department of Earth, Atmospheric,
> and Planetary Sciences
> Massachusetts Institute of Technology
>
> Office located at Southwest Research Institute
> 1050 Walnut Street, Suite 300
> Boulder, CO 80302
> USA
> (720) 208-7211
>
>
> http://web.mit.edu/azalucha/www/index.html
> _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
>
>
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