[MITgcm-support] Effect of 'vectorInvariantMomentum' flag on first order circulation

[Jean-Michel Campin]

Hi Dhruv,

OK, this is a good start. 
Could you provide me (off the list since there is some strict size limit there)
a complete copy of the set up, including the customized/modified "code" directory,
the input parameter files ( data*, eedata) and the binary input files needed
to run the set-up.
Also, if you are not using the latest MITgcm code, which version is it ?

And finally, how long would I need to run it to see some significant differences
(this was part of my earlier email, but not clearly expressed).
May be a pickup file could allow to reduce the length of these tests ?

Cheers,
Jean-Michel

On Wed, Mar 01, 2017 at 05:47:25PM -0500, Dhruv Balwada wrote:
> Hi Jean-Michel,
> 
> I tried the test you suggested by turning off all optimization, and nothing
> changed. Here are the outputs in prints of python notebooks. I have also
> attached the opt and data file. The data file for both runs point to the
> exact same forcing files on the hard drive.
> 
> Best,
> Dhruv
> 
> On Tue, Feb 28, 2017 at 10:27 AM, Dhruv Balwada <db194 at nyu.edu> wrote:
> 
> > Hello everyone,
> >
> > Thanks for the quick responses.
> >
> > @ Jean-Michel I will follow your suggestions and report back on them soon.
> >
> > Best,
> > Dhruv
> >
> >
> > On Mon, Feb 27, 2017 at 3:56 PM, Jean-Michel Campin <jmc at mit.edu> wrote:
> >
> >> Hi Dhruv,
> >>
> >> It's a strange results. Both pkgs (mom_fluxform and mom_vecinv) have been
> >> tested and used in many different configs, and no significant recent
> >> changes
> >> that would be suspicious.
> >>
> >> I suggest to try to work on a short test run:
> >> 1) long enough to detect some significant differences between the 2 cases:
> >>   vectorInvariantMomentum=T and = F
> >> 2) short enough so that the same 2 runs could be repeated with zero
> >> compiler
> >>  optimization (-ieee or -devel with many standard optfile).
> >> And from there, we could work on trying to reproduce the problem on
> >>  different machine/compiler ... etc.
> >> Once we are able to reproduce the problem, should not take too long to
> >> fix.
> >>
> >> Cheers,
> >> Jean-Michel
> >>
> >> On Thu, Feb 23, 2017 at 02:58:53PM -0500, Dhruv Balwada wrote:
> >> > Hi MITgcm community,
> >> >
> >> > I have recently been stumped an issue with the MITgcm
> >> vectorInvariantMomentum
> >> > flag.
> >> >
> >> > **The model setup** is meant to be an ideal representation of the ACC
> >> > (following Abernathey and Cessi 2014). It has the following components -
> >> > a) Linear temperature relaxation at the surface
> >> > b) Zonal wind with sinusoidal structure
> >> > c) Initial temp field is zonally symmetric and the thermocline shoals
> >> from
> >> > north to south (similar to the ACC).
> >> > d) Resolution is 20km, and domain size is 2000km * 2000km.
> >> > e) Zonally periodic and meridional walls
> >> > f) A zonal gaussian bump is the topographic feature, which is
> >> meridionaly
> >> > independent.
> >> >
> >> > **The issue** I am facing is that the circulation pattern completely
> >> > changes when I change the "vectorInvariantMomentum" flag.
> >> > When the flag is set to false (default), the model recreates an ACC like
> >> > flow. Flow is from west to east and strongly perturbed by the presence
> >> of
> >> > topography.
> >> > When the flag is set to true (default), the model does something else.
> >> Flow
> >> > is from east to west, with a strong boundary flow from the west to east
> >> > near the southern boundary.
> >> >
> >> > Any help would be appreciated.
> >> >
> >> > I have posted some visualizations and data file here -
> >> > https://sites.google.com/site/dhruvbalwada/blog/mitgcmissuew
> >> ithvectorinvariantmomentumflag
> >> >
> >> > Here is the data file (obviously the vectorinvariantmomentum flag is
> >> > changed between two runs.
> >> >
> >> >  &PARM01
> >> >
> >> > # viscosity
> >> >
> >> >  viscAr=5.6614E-04,
> >> >
> >> >  viscC4Leith=2.15,
> >> >
> >> >  viscC4Leithd=2.15,
> >> >
> >> >  viscA4GridMax=0.8,
> >> >
> >> >  useAreaViscLength=.TRUE.,
> >> >
> >> >  highOrderVorticity=.TRUE.,
> >> >
> >> > # diffusivity
> >> >
> >> >  tempAdvScheme=7,
> >> >
> >> >  diffKrT=5.44e-7,
> >> >
> >> >  saltStepping=.FALSE.,
> >> >
> >> >  staggerTimeStep=.TRUE.,
> >> >
> >> > # multiDimAdvection=.TRUE.,
> >> >
> >> >  vectorInvariantMomentum=.TRUE.,
> >> >
> >> > # initial vertical profiles of T and S
> >> >
> >> >  sRef=30*35.0000,
> >> >
> >> > # equation of state
> >> >
> >> >  eosType='LINEAR',
> >> >
> >> >  tAlpha=2.0E-04,
> >> >
> >> >  sBeta=0.0,
> >> >
> >> > # boundary conditions
> >> >
> >> >  no_slip_sides=.FALSE.,
> >> >
> >> >  no_slip_bottom=.TRUE.,
> >> >
> >> > # bottomDragLinear=1.1E-03,
> >> >
> >> >  bottomDragQuadratic=0.0021,
> >> >
> >> > # physical parameters
> >> >
> >> >  f0=-0.9E-04,
> >> >
> >> >  beta=1.0E-11,
> >> >
> >> >  gravity=9.81,
> >> >
> >> > # implicit diffusion and convective adjustment
> >> >
> >> >  implicitDiffusion=.TRUE.,
> >> >
> >> >  implicitViscosity=.TRUE.,
> >> >
> >> > # exact volume conservation
> >> >
> >> >  exactConserv=.TRUE.,
> >> >
> >> > # C-V scheme for Coriolis term
> >> >
> >> >  useCDscheme=.FALSE.,
> >> >
> >> > # partial cells for smooth topography
> >> >
> >> >  hFacMin=5.0E-02,
> >> >
> >> > # file IO stuff
> >> >
> >> >  readBinaryPrec=64,
> >> >
> >> >  useSingleCpuIO=.TRUE.,
> >> >
> >> >  debugLevel=1,
> >> >
> >> >  &
> >>
> >> > _______________________________________________
> >> > MITgcm-support mailing list
> >> > MITgcm-support at mitgcm.org
> >> > http://mitgcm.org/mailman/listinfo/mitgcm-support
> >>
> >>
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> >>
> >
> >





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