[MITgcm-support] 2D boundary conditions at the poles

Angela Marie Zalucha azalucha at MIT.EDU
Sat Nov 12 11:47:53 EST 2011


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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