[MITgcm-support] Open Boundary Conditions in MITgcm

[fancer fancer]

Martin,

Model has diverge, If I set useOBCSbalance=.FALSE.
I think that the way with a sponge layers is most suitable.

Thanks for help.
Sincerely, Serge Semin.

On Tue, Mar 1, 2011 at 12:52 PM, Martin Losch <Martin.Losch at awi.de> wrote:

> Serge,
>
> I do not know enough about the orlanski implementation to provide more
> insight than you probably already have. I agree that the code is difficult
> to read (that's why I never understood, what's really going). I suggest that
> you hope that someone else will provide and answer, or you'll have to go and
> read the original papers. In orlanski_east.F there is some text about the
> parameters and suggestions about setting them.
>
> Your configuration looks OK to me, but what happens when you do not use the
> balancing code (useOBCSbalance = .false.)? Maybe this velocity correction
> causes some of the reflection?
>
> Martin
>
> On Feb 28, 2011, at 9:59 PM, fancer fancer wrote:
>
> > Hi Martin. Sorry for belated answer and thanks for replies.
> >
> > There are small changes then I use Orlanski conditions, reflected waves
> have smaller amplitudes, but they are still reflected.
> > I use default values CMAX and cVelTimeScale. I have not found some
> information about Orlanski radiation boundary condition in free access.
> Could You please tell me some formula or rule for these parameters selection
> (for waves reflection minimizing)? Not trivial task to get it from code.
> >
> > P.S. My project in attachment, if it needed.
> >
> > -Serge
> >
> > On Thu, Feb 24, 2011 at 10:31 AM, Martin Losch <Martin.Losch at awi.de>
> wrote:
> > Serge,
> > claim
> > you might have noticed that the documentation of the obcs-pkg is
> incomplete:
> > <http://mitgcm.org/public/r2_manual/latest/online_documents/node236.html
> >
> > but can find all the information about the OB_Ieast etc. indices and
> other run-time parameters. For more you'll have to consult the code in
> pkg/obcs and the corresponding experiments in verification I am afraid.
> >
> > There is a orlanski-radiation conditions. To turn it on you need to
> re-compile with
> > #define ALLOW_ORLANSKI
> > in OBCS_OPTIONS.h and useOrlanskiNorth/South/East/West=.true. for the
> boundary of intererst. There are some experiments that use this option (e.g.
> tutorial_plume_on_slope, dome). If you are not happy with that, you'll need
> to implement something on your own.
> >
> > I hope this helps,
> > Martin
> >
> > On Feb 20, 2011, at 5:12 PM, fancer fancer wrote:
> >
> > > Hello, MIT gcm support.
> > > I am novic at modeling with MIT gcm, thus I have several questions
> about this model and about obcs package, especially.
> > >       • My first application describe itnternal waves propagation,
> generated by temperature and salinity stratification, in 2D area. This is
> the trivial task, because MIT gcm has internal waves verification example.
> It is necessary, what waves go through boundaries, but not reflect of that
> boundaries. How made it with obcs package or with other way? I made many
> experiments, but whitout positive results.
> > >       • Is there more detailed information about open boundies setting
> in MIT gcm, it is desirable with picture, where OB_Ieast, OB_Iwest,
> OB_Jsouth, OB_Jnorth represented in a modeling area?
> > > In advance, thanks for help.
> > > Yours sincerely, Serge Semin.
> > > P.S, Sorry for my emglish, I'm still learning.
> > > _______________________________________________
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> > > MITgcm-support at mitgcm.org
> > > http://mitgcm.org/mailman/listinfo/mitgcm-support
> >
> >
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> >
> > <exp7_2D_OBCS.tar.gz>_______________________________________________
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