[MITgcm-support] problems at tile bdys?

[Jean-Michel Campin]

Hi Yuan,

The problem was easy to reproduced. Found and fixed.

There was nothing wrong in the publicly available MITgcm code;
the problem was in wrong modifications of the original source code. 

re-run for 1 day and have attached the plot of pot-temp @ lev k=35 
along a constant lat (j=48).

Cheers,
Jean-Michel

On Mon, Jun 17, 2013 at 11:43:48AM -0700, Yuan Lian wrote:
> Hi Jean-Michel,
> 
> I will do this asap. I am rerunning the test and will provide some
> plots to show the issues.
> 
> Thanks.
> 
> Best,
> Yuan
> 
> 
> On 6/17/13 5:41 AM, Jean-Michel Campin wrote:
> >Hi Yuan,
> >
> >Could you proceed with the same recommendation (sending tar file of dir with
> >modified/customized source file and all data* files for this set-up)
> >or is there too much source-code involved ?
> >
> >If we are lucky, it could be the same Pb and then will be easier to identify
> >with 2 set-up (instead of just 1). Otherwise, might have 2 separate Pb to fix ...
> >
> >Cheers,
> >Jean-Michel
> >
> >On Sun, Jun 16, 2013 at 09:35:08PM -0700, Yuan Lian wrote:
> >>Hi Jean-Michel,
> >>
> >>I found the similar behavior of MITgcm when there are multiple tiles in x direction. The issue is particularly obvious when active tracers are enabled, e.g. water cycle, where I can see the periodical oscillation of tracers including temperature at the boundaries between the tiles. The problem is less apparent in y direction. I am wondering if it has something to do with exchange routines in x direction. The simulations are done in 3d channel. Thanks.
> >>
> >>Best,
> >>Yuan
> >>
> >>Jean-Michel Campin <jmc at ocean.mit.edu> wrote:
> >>
> >>>Hi Jody,
> >>>
> >>>Could you send (in a tar file) the directory that contains all the
> >>>modified/customized files you are using (the argument of "genmake2
> >>>-mods" command)
> >>>as well as all the parameter files (all data* files) for this set-up ?
> >>>Also, if you are not using the latest version of MITgcm code, which
> >>>version
> >>>(checkpointXYz ? or time of the latest "cvs update") are you using ?
> >>>
> >>>It's possible that we can find the problem like this; otherwise, will
> >>>have
> >>>to try to reproduce it (and in this case will also need the binary
> >>>input files).
> >>>
> >>>Cheers,
> >>>Jean-Michel
> >>>
> >>>On Sat, Jun 15, 2013 at 11:03:30PM -0700, Jody Klymak wrote:
> >>>>Hi All,
> >>>>
> >>>>I ran a simulation in a 2-D channel but three-D in setup, and all ran
> >>>fine.  Well except it stayed 2-D because there was nothing to cause
> >>>there to be spanwise motion.  The simulations are nonhydrostatic.
> >>>>So, I added a very small amount of three d by a few different
> >>>methods, and everytime, no matter how I set up the three dimensionality
> >>>(bottom roughness, initial velocities, surface displacements) there
> >>>would an instability at the same spot in x.  It turns out it is a tile
> >>>boundary in the middle of the domain.
> >>>>I'm using advection scheme 33, and chnaged OLx and OLy to 5, but
> >>>still the same problem.  I tried a few other advection schemes, with
> >>>the same issue (it happens in a hundred or so timesteps, so its easy to
> >>>debug, at least).  I also tried upping the iterations on the CG3d
> >>>solver, but that didn't help at all.
> >>>>I've now gone back to the same setup I started with, but changed by
> >>>tile layout (half as many tiles), and the instability is gone.
> >>>>Has anybody run into this?  Any suggestions for a fix or what to look
> >>>for?  (I guess the stupid fix is not to use that tile configuration,
> >>>but that seems flakey).
> >>>>Thanks,   Jody
> >>>>
> >>>>
> >>>>--
> >>>>Jody Klymak
> >>>>http://web.uvic.ca/~jklymak/
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>_______________________________________________
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> >>>>MITgcm-support at mitgcm.org
> >>>>http://mitgcm.org/mailman/listinfo/mitgcm-support
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> >>>http://mitgcm.org/mailman/listinfo/mitgcm-support
> >>-- 
> >>Sent from my Android phone with K-9 Mail. Please excuse my brevity.
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> >
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> 
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