[MITgcm-devel] seaice

[Jinlun Zhang]

The sea ice grid info is derived from ocean grid, so I guess the 
difference must be from the different advection schemes.
Jinlun

Martin Losch wrote:

> Dimitris and other seaice modelers,
>
> I have modified
> dynsolver.F
> diffus.F
> advect.F
> to replace all grid information (dxtice,dytice,etc) with generic  
> MITgcm grid parameters (dxF,dyF, etc, defined in GRID.h)
> So far, this has NOT changed the results of lab_sea experiment,  
> except for the advection part.
> I tried to use a flux-form, similar to the second-order central  
> difference form in pkg/generic_advection/gad_c2_adv_x.F etc. but  
> there are small differences (the model needs a better advection  
> scheme that is positive!!!).
>
> Unfortunately on a cubed_sphere grid with seaice, the results do  
> change a lot, but is that surprising?
>
> What also changes the results:
> in dynsolver.F:
> RADIUS = rSphere (default = 6370. _d 3)
> TWO*OMEGA*SINEICE(I,J,bi,bj) = _fCoriG(I,J,bi,bj) (=2._d0*omega*sin 
> (_yG(i,j,bi,bj)*deg2rad)
>
> I don't see why.
>
> how should I proceed?:
> I could send the routines around for testing or looking at and we  
> could agree on checking them in or not checking them in.
> Or I could forget about the project altogether, because it is tedious  
> and unrewarding. Is it worth it? Can you deal with the small  
> differences that these changes imply?
>
> Martin
>
>
> On Feb 13, 2006, at 3:37 PM, Dimitris Menemenlis wrote:
>
>> Martin, I am attaching a draft wish list for MITgcm sea-ice code  for 
>> you and others to consider and modify.  The list is based on  your 
>> recent e-mails and work on ice shelves as well as on  discussions 
>> with Jean-Michel and Patrick during ECCO meeting two  weeks ago and 
>> with Elizabeth Hunke and Bill Lipscomb at NCAR last  week.  I am not 
>> sure when these things will happen and in what  order.  I am 
>> presently trying to hire someone that can help move  the MITgcm 
>> sea-ice code forward.  Timing also depends on Jinlun's  timetable and 
>> availability.
>>
>> 1. Clean-up grid parameters as you suggest.  Make sure that there  
>> are no duplicate or repeated computations.  Use model/inc/GRID.h  
>> parameters where possible, define the rest in pkg/seaice/ 
>> SEAICE_GRID.h and seaice_init.F.
>>
>> 2. Adapt LSR solver for curvilinear coordinates so that it is  
>> "properly" compatible with cubed-sphere and terraced grids.
>>
>> 3. Port LSR solver to C-grid.  This is something that Jinlun is  
>> working on for GISS, and he may be able to spend two months next  
>> year to implement on MITgcm.
>>
>> 4. Better coupling of pkg/seaice thermodynamics with surface level,  
>> similar to what Jean-Michel has done for pkg/thsice.
>>
>> 5. Coupling of pkg/thsice thermodynamics with pkg/seaice dynamics.
>>
>> 6. Ice shelves and cavern representation.
>>
>> 7. Import more modern, multi-category sea-ice model.  The plan is  to 
>> import the Los Alamos CICE sea ice model (http:// 
>> climate.lanl.gov/Models/CICE/), ideally with interchangeable  
>> dynamics between Jinlun's LSR VP solver and Elizabeth's explicit  EVP 
>> solver.
>>
>> Dimitris
>>
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>
>
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-- 

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