[Mitgcm-support] Re: pkg/seaice and pkg/exf

[mitgcm-support at dev.mitgcm.org]

Tom, by default the initial sea-ice thickness is everywhere 1-m thick.  This
means that in tropical oceans, there will be 92 cm of freshwater, and the
equivalent negative latent heat flux, dumped in the ocean during the first
time step.  Hence the differences that you see in your test cases between
useSEAICE .TRUE. and useSEAICE .FALSE.

I was bypassing this problem by always starting from a sea-ice restart file.
But that's not very convenient so I have added an HeffFile parameter that can
be specified in "data.seaice".

Please update your code using "cvs up -r release1", then add:

 &SEAICE_PARM01
   ...
   HeffFile          = 'ZERO.bin'
 &

to data.seaice, where ZERO.bin is a real*4, direct-access, binary file, full
of zeros, that has the horizontal dimension of your model grid.  This will
set the initial sea-ice thickness to zero everywhere in your domain, so the
numbers from pkg/exf and from pkg/seaice should be similar (to within
interpolation accuracy for fu and fv).

Let me know if this fixes your problem.

Cheers, D.

-- 
Dimitris Menemenlis                      menemenlis at jpl.nasa.gov
Jet Propulsion Lab, MS 300-323           tel: 818-354-1656
4800 Oak Grove Dr, Pasadena CA 91109     fax: 818-393-6720


>> Dimitris,
>>  
>> The fields are different. With SEAICE_EXTERNAL_FLUXES def'ed I ran with
>> useSEAICE on then off, dumping FU, FV, EmPmR, Qsw, and Qnet. After 1 step
>> I get the fields attached. The LH column is for useSEAICE .TRUE., the RH
>> column is for useSEAICE .FALSE.
>>  
>> All of the original forcing fields are in range according to exf_fields.h
>> (I use the atmospheric state).
>>  
>> It looks like maybe the latent heat of evaporation is wrong somehow: check
>> out EmPmR and Qnet. Everything else looks OK.
>>  
>> Tom.