[MITgcm-devel] ICE workshop - recap and homework!

[Menemenlis, Dimitris (3248)]

Gael et al., is this a good time for Ian to check-in
his treatment of FrazilForcingT in seaice_growth.F ?

Cheers

Dimitris Menemenlis

On Mar 6, 2012, at 11:26 PM, Gael Forget wrote:

> Hi Martin et al,
> 
> I am moving some of the "ICE workshop - recap and homework!" thread that followed from the MIT ice workshop to devel list.
> 
>> Further, for checking the conservation properties in my configuration it would be helpful if Gael could provide a data.diagnostics.
> Will follow.
> 
>> About the seaice defaults: I am not clear about the turbulent flux formulae. The implementation that I updated to today requires that I set
>> #define MCPHEE_OCEAN_ICE_HEAT_FLUX
>> #define GRADIENT_MIXED_LAYER_TURBULENCE_FACTOR
>> Do we need to set anything else in data.seaice in order to get the agreed parameter set?
> I know it's confusing even for me at this point. It took me a while to figure out a more of less adequate way (see below)
> of unifying the various flavours of this term's specification that had been added over the years. I mostly hope that this 
> merge keeps non-specialists of pkg/seaice from overlooking default changes when they update their copy of MITgcm.
> 
> Below I give explanations  and guidelines (correct ones I hope) for using the new run time parameters.
> I do the same for SEAICE_MULTICATEGORY and SEAICE_VARIABLE_FREEZING_POINT.
> That information is also in SEAICE_PARAMS.h and/or seaice_check.F and/or in the standard output.
> 
> Cheers,
> Gael
> 
> old def/undef SEAICE_VARIABLE_FREEZING_POINT : now unified way of specifying sea water freezing 
> point. So it should always be defined and the rest is done with run time params. Changed default.
> -----------------------------------------------------------------------------------------
> old default : SEAICE_tempFrz0 = -1.96, SEAICE_dTempFrz_dS = 0.
> new default : SEAICE_tempFrz0 = 0.0901, SEAICE_dTempFrz_dS = -0.0575
> ?? do we have a precise reference for 0.0901 + S * SEAICE_dTempFrz_dS ??
> 
> 
> def/undef SEAICE_MULTICATEGORY : no change to default. So use CPP as before.
> But added run time switch : set SEAICE_multDim to 1 or 7, regardless of CPP. It is assumed 
> that user provide pickup accordingly, as before. Pickup code will likely need consolidation.
> ---------------------------------------------------------------------------------------------------------
> 
> 
> old def/undef MCPHEE_OCEAN_ICE_HEAT_FLUX & GRADIENT_MIXED_LAYER_TURBULENCE_FACTOR : 
> now unified way of specifying the turb. ocean-ice flux. So the CPPs should always be defined and the rest is
> done with run time params. Old run time params can still be used. Changed default.
> ----------------------------------------------------------------------------------------------------------------------------
> defaults etc :
> -- old default    : SEAICE_mcPheePiston = drf(1)/SEAICE_deltaTtherm, SEAICE_frazilFrac=1., SEAICE_mcPheeTaper=0.,
> -- new default    : SEAICE_mcPheePiston = 0.000875, SEAICE_frazilFrac=1., SEAICE_mcPheeTaper=0.,
> -- baseline params : SEAICE_mcPheePiston = 0.000875, SEAICE_frazilFrac=1., SEAICE_mcPheeTaper=0.92,
> -- old mcphee cpp : SEAICE_mcPheePiston = 0.000875, SEAICE_frazilFrac=0., SEAICE_mcPheeTaper=0.92,
> -- SEAICE_mcPheeStepFunc always false (old GRADIENT_MIXED_LAYER_TURBULENCE_FACTOR).
> conversions of old to new params :
> -- SEAICE_mcPheePiston = dRf(kSurface)/SEAICE_gamma_t
> -- SEAICE_frazilFrac = SEAICE_deltaTtherm/SEAICE_gamma_t_frz
> -- SEAICE_mcPheePiston = SEAICE_availHeatFrac * dRf(kSurface)/SEAICE_deltaTtherm
> -- SEAICE_frazilFrac = SEAICE_availHeatFracFrz
> ?? do we have a precise reference for 0.000875 and 0.92 ??
> 
> 
> 
> 
> 
> 
> 
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