[MITgcm-devel] description of seaice parameters

[Dimitris Menemenlis]

Hi Martin, thanks for sweeping through pkg/seaice.  That's really 
helpful.  A few more comments in addition to Jinlun's:

> The biggest difference is in SEAICE_freeze, which is -1.96degC in
> seaice_readparms.F, but -1.86degC in his code. Maybe still another
> reason for the thin ice around Antarctica and the large erroneous
> polynyas in the high-res cubed sphere experiments.

I have run a sensitivity experiment with -1.8 deg C freezing point, 
which gives slightly thicker ice around Antarctica, as expected. 
Eventually, I assume we will want this to depend on salinity.

> Also he uses a smaller value of pstart=1.5e4 (instead of
> SEAICE_strength=2.75e4 in seaice_readparms.F). Only FYI.

I have also run a sensitivity experiment for this parameter.  Slightly 
larger, rather than lower, pstar seems to help reduce the Polynya problem.

> However, we found that the parameters 
> SEAICE_sensHeat/latentWater/latentIce are not really the coefficients
> as described in SEAICE_READPARMS.h but (density of air)*(heat 
> capacity of air/latent heat of water/latent heat of ice)*(transfer 
> coefficient)
> At least, that's what we found by comparing the code and default 
> values. If you want me to do it I'll change the description in 
> SEAICE_READPARAMS.h to reflect this, so that future seaice-novices do
> not stumble over this?

I remember working out what these constants actually were at some point 
in time and that there were some scaling factors.  But I forgot to add 
the scaling factors to descriptions in SEAICE_PARAMS.h as I should have. 
  It would be great if you can update the definitions.

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