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

Thu Mar 2 14:08:51 EST 2017

Hi Jean-Michel,

The experiment setup is now available at -
https://github.com/dhruvbalwada/channel_run_20km

I am using a version of the MITgcm that I downloaded in the beginning of
February.

The difference between two runs appears in a matter of 1 year of the run. I
would probably run it for 2-3 years to see it clearly. On the computers
here with 25 cores it took about 1 hour to run. So, its very fast.

Let me know if you need any other files, and I can add them to the git
directory.

Thanks,
Dhruv

On Thu, Mar 2, 2017 at 10:37 AM, Jean-Michel Campin <jmc at mit.edu> wrote:

> 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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