[MITgcm-devel] depressed Eta and sIceLoad

[Martin Losch]

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