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

Dhruv Balwada db194 at nyu.edu
Fri Mar 3 00:34:35 EST 2017 

Hi Bruno,

Removing the topography made the solutions for the two cases be the same.
This is crazy interesting, I think I need to understand your paper better.

Best,
Dhruv



On Thu, Mar 2, 2017 at 2:09 PM, Dhruv Balwada <db194 at nyu.edu> wrote:

> Hi Bruno,
>
> I haven't removed the topography. I will set that up now. I did try to do
> the run with no-slip and free-slip walls. The solution was the same in
> both.
>
> Best,
> Dhruv
>
> On Thu, Mar 2, 2017 at 2:08 PM, Dhruv Balwada <db194 at nyu.edu> wrote:
>
>> Hi Jean-Michel,
>>
>> The experiment setup is now available at - https://github.com/dhruvbalw
>> ada/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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