[MITgcm-devel] depressed Eta and sIceLoad

[Martin Losch]

another comment on Jinlun's fix:

in the current version of growth.F (not the one that Jinlun sent),  
YNEG is in m seaice, this is added  to QNET:
>           QNET(I,J,bi,bj)=QNET(I,J,bi,bj)
>      &         +YNEG(I,J,bi,bj)/SEAICE_deltaTtherm
>      &         *maskC(I,J,kSurface,bi,bj)
>      &         *HeatCapacity_Cp*recip_horiVertRatio*rhoConst
>      &         *drF(kSurface)*hFacC(i,j,kSurface,bi,bj)
If now YNEG is modified by melting snow the above line should  
probably happen after this further modification. right?

Martin
On 25 Oct 2006, at 10:25, Martin Losch wrote:

> Hi Jinlun et al.,
>
> please have a quick look at 10day averages of HEFF and HSNOW in  
> July and January (after 100 years) in
> http://mitgcm.org/~mlosch/ice_iter72360.png (Jul)
> http://mitgcm.org/~mlosch/ice_iter72020.png (Jan)
> run22 is without advection of snow (both runs are with evap*(1- 
> area)), run26 is with advection of snow. Unfortunately, the runs  
> are not exactly comparable because I had to use a 1-order upwind  
> scheme for advection the snow, so that run26 uses the 1-order  
> upwind scheme (for HSNOW, HEFF and AREA) and run22 the traditional  
> 2nd order central differences scheme (but only for HEFF and AREA),  
> no "flooding" in either case. What you see is that the advection  
> reduces the amplitudes of the snow be a factor of 100, but maybe  
> that's just the 1-order upwind scheme? Also the snow is in areas  
> where it shouldn't be.
> Not shown: My (it's not mine, but as opposed to Jinlun's  
> suggestion) simple flooding scheme removes this snow at the  
> "expense" of much increased ice thicknesses, Jinlun's scheme  
> reduces the snow heights even further (I only have 10year yet, but  
> it's already <20cm as opposed to <50cm in "my" runs), and the ice  
> thickness is not increased as much. Also the freshwater flux into  
> the ocean appears to be reduced (higher surface salinities) so that  
> as a first conclusion I would say that Jinlun's fix appears to be  
> quite appropriate (as opposed to mine). More analyses to follow.
>
> Martin
>
>
> On 24 Oct 2006, at 23:19, Jinlun Zhang wrote:
>
>> Hi Martin,
>> Advecting snow is certainly better than not, but I am not sure if  
>> it would solve the problem of getting big numbers for snow.
>> Jinlun
>>
>> mlosch at awi-bremerhaven.de wrote:
>>
>>> Hi Jinlun,
>>> thanks, I'll try this out tomorrow. What about advecting HSNOW?  
>>> Why can that be neglected?
>>>
>>> Martin
>>>
>>> Martin Losch
>>> Alfred Wegener Institute Postfach 120161, 27515 Bremerhaven,  
>>> Germany; Tel./Fax: ++49(0471)4831-1872/1797
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: Jinlun Zhang <zhang at apl.washington.edu>
>>> Date: Tuesday, October 24, 2006 7:56 pm
>>> Subject: Re: [MITgcm-devel] depressed Eta and sIceLoad
>>>
>>>
>>>> Dimitris and all,
>>>> The ncep precip in Antarctic is way too much, but I have  
>>>> moidfied growth.F  to, hopefully, improve things a little bit.  
>>>> The modification would allow the ocean to melt  the left-over  
>>>> snow when ice is gone (seach jz for the modi's in the code) .  
>>>> See if there is any improvement ot of it.
>>>> Jinlun
>>>>
>>>> Dimitris Menemenlis wrote:
>>>>
>>>>
>>>>> It looks bad:
>>>>> http://ecco2.jpl.nasa.gov/data2/cube/cube38/pickup/HSNOW.jpg
>>>>> 20 to 60 m of snow over open water.  This is after a 12-year
>>>>> integration on the cubed sphere.
>>>>>
>>>>> Dimitris
>>>>> _______________________________________________
>>>>> MITgcm-devel mailing list
>>>>> MITgcm-devel at mitgcm.org
>>>>> http://mitgcm.org/mailman/listinfo/mitgcm-devel
>>>>>
>>>> -- 
>>>>
>>>> Jinlun Zhang
>>>> Polar Science Center, Applied Physics Laboratory
>>>> University of Washington, 1013 NE 40th St, Seattle, WA 98105-6698
>>>>
>>>> Phone: (206)-543-5569;  Fax: (206)-616-3142
>>>> zhang at apl.washington.edu
>>>> http://psc.apl.washington.edu/pscweb2002/Staff/zhang/zhang.html
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
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