[MITgcm-devel] depressed Eta and sIceLoad

[Jean-Michel Campin]

Hi Martin, 

I don't have any problem with snow when I use pkg thSIce
(since it get converted into ice if below sea-level).
But with pkg seaice, I had to modify the pickup
of the cs-510 run (just remove the exces of snow)
to turn on the ice-loading, because there was too much snow
(max ~ 200m).
The thing that was missing in pkg seaice, was a diagnostic for 
the snow thickness.

Do you still have the low SSH with the flooding added to
pkg/seaice (since it's not currently in, right ?) ?

Jean-Michel

On Tue, Oct 24, 2006 at 03:51:10PM +0200, Martin Losch wrote:
> EVAP should definitely be fixed (will change results!)
> 
> Please have a look at the snow. I have now implemented both advection  
> of snow and flooding (btw, the flooding alogrithm is part of  
> thsice_calc_thickn.F) and the excessive snow (without ice!) and  
> consequently the Eta depression goes away in first tests (I have not  
> tried to use advection of snow without flooding and vice versa). I  
> don't see why this problem should be particular to me (as Jean-Michel  
> pointed out that he also got a lot of snow), so please check your  
> runs. I use CORE (ncep) precipitation with reasonable values so there  
> is no particular reason for the accumulation.
> 
> Martin
> 
> On 24 Oct 2006, at 15:31, Patrick Heimbach wrote:
> 
> >
> >Martin, DImitris,
> >
> >re. EVAP,
> >the ECCO runs now with sea-ice
> >show surprising large near-surf. salinity misfits
> >in the SO, following seasonal ice cycle
> >and pronounced in Weddell Sea.
> >So this is very consistent with Martin's finding.
> >Maybe time to check in the fix?
> >Don't think we have snow problems though
> >(although haven't diagnosed anything yet,
> >but SSH drift with realFreshWater stays bounded).
> >
> >-p.
> >
> >
> >
> >On Tue, 2006-10-24 at 08:20, Martin Losch wrote:
> >>Dimitris,
> >>I really think that this will also get rid of your problems in the
> >>Weddell Sea. As far as I remember you had the problem of too much
> >>convection, erorsion of stratification and consequently too little
> >>seaice towards the end of your 10-12year integration. It appears to
> >>me that EVAP is the culprit, not KPP or missing shelfice water. With
> >>this bug I had -1.9 all the way to the bottom around Antarctic
> >>already after 10-20years. After correction of the bug, the
> >>stratification remains stable for 100year (I haven't run it any
> >>longer), without any restoring SST/SSS to Levitus.
> >>
> >>I still have a problem with seaice though, and that's the snow. Far
> >>too much snow (100m) that even remains, when the seaice is gone in
> >>summer. I use all the default parameters.
> >>Is it a problem that snow is not advected along with ice?
> >>One could think of a simple flooding algorithm that converts
> >>submerged snow into ice:
> >>           hDraft = (HSNOW(I,J,bi,bj)*330. _d 0
> >>      &             +HEFF(I,J,1,bi,bj)*SEAICE_rhoIce)/1000. _d 0
> >>           hFlood = hDraft - MIN(hDraft,HEFF(I,J,1,bi,bj))
> >>           HEFF(I,J,1,bi,bj) = HEFF(I,J,1,bi,bj) + hFlood
> >>           HSNOW(I,J,bi,bj) = MAX(0. _d 0,HSNOW(I,J,bi,bj)-hFlood/ 
> >>SDF)
> >>
> >>
> >>Martin
> >>On 23 Oct 2006, at 18:50, Dimitris Menemenlis wrote:
> >>
> >>>Martin, that's brilliant!  EVAP, as it is computed right now,
> >>>should definitely be weighted by (ONE-AREA(I,J,2,bi,bj)), that is,
> >>>set to zero under sea ice.  I agree, I think this is a bug.  Can't
> >>>wait to give it a try in the 18-km cube. Cheers, Dimitris
> >>>
> >>>-- 
> >>>Dimitris Menemenlis <menemenlis at jpl.nasa.gov>
> >>>Jet Propulsion Lab, California Institute of Technology
> >>>MS 300-323, 4800 Oak Grove Dr, Pasadena CA 91109-8099
> >>>tel: 818-354-1656;  fax: 818-393-6720
> >>>_______________________________________________
> >>>MITgcm-devel mailing list
> >>>MITgcm-devel at mitgcm.org
> >>>http://mitgcm.org/mailman/listinfo/mitgcm-devel
> >>
> >>_______________________________________________
> >>MITgcm-devel mailing list
> >>MITgcm-devel at mitgcm.org
> >>http://mitgcm.org/mailman/listinfo/mitgcm-devel
> >-- 
> >Dr Patrick Heimbach | heimbach at mit.edu | http://www.mit.edu/~heimbach
> >MIT | EAPS, 54-1518 | 77 Massachusetts Ave | Cambridge, MA 02139, USA
> >FON: +1-617-253-5259 | FAX: +1-617-253-4464 | SKYPE: patrick.heimbach
> >
> >_______________________________________________
> >MITgcm-devel mailing list
> >MITgcm-devel at mitgcm.org
> >http://mitgcm.org/mailman/listinfo/mitgcm-devel
> 
> _______________________________________________
> MITgcm-devel mailing list
> MITgcm-devel at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-devel