[MITgcm-support] too SMALL rStarFac

[Christoph Voelker]

Hi Alexandre,

you are probably right that it is a gridpoint where the sea-ice is
getting unrealistically thick. This is often caused by working with a
bathymetry that includes some narrow bays; I just recently had the same
and discovered that by gridding the topography on my grid I had overseen
that I had a 'fjord' just one grid-point wide and 4 grid-points long
somewhere at the Antarctic Peninsula, with a 'hook' at the end. Here the
ice just could not flow away.
I then filled that bay by hand by playing with the topography file and
the problem was gone. Although this is a drastic step it is probably not
much more wrong than artificially limiting sea-ice thickness (btw.: the
old possibility to do that setting MAX_HEFF in data.seaice is gone in
the newer code versions). The crash report usually tells you where rstar
was getting unrealistic, so you can check your topgraphy around that point.
Of course you can only do this if you think that the gridpoints that you
fill with land are unimportant in terms of water mass pathways; this may
e.g. not be such a good idea if it is a narrow strait connecting two
ocean basins. Then you maye have to broaden that strait artificially..

Cheers, Christoph 

Am 13/06/16 um 15:03 schrieb Alexandre Pohl:
>
> Hi David,
>
> Here is the monitor output.
>
> *** ocean monitor (~ 3 model-hours before the execution stops)
> (PID.TID 0000.0001) %MON dynstat_eta_max              =  
> 4.3794885028966E-01
> (PID.TID 0000.0001) %MON dynstat_eta_min              =
>  -1.6470044106306E+02
> (PID.TID 0000.0001) %MON dynstat_eta_mean             =
>  -1.2391670181170E+01
>
> *** atmos thsice monitor (~ 15 model-hours before the execution stops)
> (PID.TID 0000.0001) %MON thSI_IceH_ave_G              =  
> 5.4363138743973E+01
> (PID.TID 0000.0001) %MON thSI_IceH_max_S              =  
> 1.9725741528571E+02
> (PID.TID 0000.0001) %MON thSI_IceH_max_N              =  
> 1.9723363538611E+02
>
> I would say that the model stops because sea ice gets very thick (up
> to ~ 200 m in both hemispheres) over costal areas typified by a
> shallow bathymetry (see attached maps of ETAN and SI thickness).
>
> Is there any way to solve this ? Do I have to go back to my former
> model setup, by restricting the maximum sea ice thickness to ~ 10 m,
> as in the 'cpl_aim+ocn’ verification case ?
>
> Thanks !
> Alexandre
>
>
>
>
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-support


-- 
Christoph Voelker
Alfred Wegener Institute for Polar and Marine Research
Am Handelshafen 12
27570 Bremerhaven, Germany
e: Christoph.Voelker at awi.de
t: +49 471 4831 1848

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mitgcm.org/pipermail/mitgcm-support/attachments/20160613/a07117e7/attachment.htm>