[MITgcm-support] obcs/exf interactions

[Tom Haine]

Jinlun, 

Attached are figures of various surface fields, forcing fields, and ice
fields from close to the time Alistair is starting his integrations.
These results are from the old code. 

I guess pkg/exf changes (presumably in the stress computation) might
explain the difference Alistair sees, although I don't know why they
would be concentrated at the ice edge.

Tom.
 

On Thu, 2004-10-07 at 14:32, Jinlun Zhang wrote:
> I am puzzled by the straght line after some time steps. The initial ice
> condition is a straght line, but after a while it should change. Here is my
> guess:
> (1) Ice model might not be excuted so the initial ice edge is kept unchanged.
> Need to look at ice output.
> (2) Different ocean model versions might get surface flux differently over areas
> partially covered by ice (exf to blame?)
> Jinlun
> 
> Tom Haine wrote:
> 
> > Dear Jinlun,
> >
> > I don't know. Alistair's plots are differences between our code (hacked
> > ecco_c50_e29 with 2/2003 pkg/seaice) and the latest HEAD release. The
> > plots he showed are difference plots at (guessing) 300m after a few
> > steps. There is a difference in 300m velocity at the position of the ice
> > edge at that time. My guess is that it persists but I don't know for
> > sure. The ice is moderately thick (about 1m) and dense northwest of the
> > line you see (my ugly attempt to put seaice on the shelf). Elsewhere
> > there is no seaice.
> >
> > Of course, I don't know which velocity field is better (do you have a
> > preference?). But it would be nice to locate the origin of the
> > discrepancy.
> >
> > Tom.
> >
> > On Thu, 2004-10-07 at 13:15, Jinlun Zhang wrote:
> > > Tom,
> > >
> > > OK you are using the LSR solver.  I don't think the solver has been changed
> > > since 2/2003,  only some cosmetic changes. Do you see the ice edge just at
> > > initial 1 or 2 time steps or the ice edge persists?
> > >
> > > JInlun
> > >
> > > Tom Haine wrote:
> > >
> > > > Hi Jinlun,
> > > >
> > > > We use lsr:
> > > >
> > > >       SEAICEuseLSR = .TRUE.,
> > > >
> > > > in data.seaice. Without this line (i.e., with the adi solver) it doesn't
> > > > work in parallel (following discussion on this list in April this year).
> > > >
> > > > We're using pkg/seaice from around February 2003. I think several of the
> > > > key routines have been updated since then. Can this account for the
> > > > velocity differences Alistair sees?
> > > >
> > > > Tom.
> > >
> 
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