[MITgcm-support] seaice_salinity

[Michael Schodlok]

 Matt,
 The values for SEAICE_WaterDrag and SEAICE_Drag seem to be ok,
 at least those are similar to what we use in ECCO2. However, 
SEAICE_strength
 seems to be a bit low. The optimized ECCO2 value is around 13000. I guess
 that's what you're concerned with, not the value of SEAICE_drag, right?
 cheers
 Michael

 

> Hello,
>
> OK, so I was only able to make the seaice dynamics stable by turning
> down the drags ( I was able to run with SEAICE_WaterDrag = 5 and
> SEAICE_drag = 0.001) and turning down the SEAICE_strength (to a value
> of 5e-3) and turning down the lsr error to 1e-5.
>
> I am concerned because a very small SEAICE_drag is likely unrealistic
> for the SO's largely rough first year ice, and (perhaps more
> importantly) because if the winds increase during optimization it may
> drive the model back unstable.
>
> I am also disappointed in that running with seaice diagnostics on and
> LSR_error = 1e-5 has about doubled the runtime...making using seaice
> dynamics not very practical.
>
> So any advice...options.  Would coding a simple free drift model be
> more stable (and perhaps somewhat realistic).  Any ideas?
>
> Thanks a lot,
> Matt
>
>
>
>
> On Nov 11, 2008, at 8:13 PM, Dimitris Menemenlis wrote:
>
>   
>> The CS510 solution also has some very saline water in narrow fjords
>> around Antarctica.  I think what might be happening is that ice is
>> acting as a salinity pump, taking freshwater out of the fjord, when
>> ice dynamics are turned on, but there is no mechanism for flushing
>> the salty water out in the model ocean.  Let me know what you
>> find.  D.
>>
>> On Nov 11, 2008, at 7:49 PM, Matthew Mazloff wrote:
>>
>>     
>>> Hi Dimitris,
>>>
>>> The extremes are happening over narrow fjords.  But with seaice
>>> dynamics off they dont occur.  The coldest it gets is -3.14.
>>>
>>> And yes, I have  SEAICE_gamma_t     = 259200.
>>>
>>> Thanks for the help,
>>> -Matt
>>>       
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>
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Michael Schodlok <schodlok at jpl.nasa.gov>
Jet Propulsion Lab/
California Institute of Technology
MS 300-323
4800 Oak Grove Dr
Pasadena 
CA 91109-8099 
USA
Tel: +1-818-354-4015  
Fax: +1-818-393-6720

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