[MITgcm-devel] depressed Eta and sIceLoad

[Jinlun Zhang]

Hi Dimitris,

Yes, I do mean sublimation or condensation at  the top of ice or snow, 
which is not very significant (I would think). However, if the forcing 
is correct, evap should be small in ice covered area anyway. Or if the 
evap forcing is correct in the sense that it represents the same amount 
of loss or gain of water as would be the case with sublimation or 
condensation. But if you all agree with it being a  permenent fix, it is 
ok with me.

Cheers, Jinlun

Dimitris Menemenlis wrote:

> Hi Jinlun,
>
>> I don't think this was a bug since evap occurs in ice covered area too.
>
>
> I am assuming you mean evaporation from "top" of ice so the physics 
> would be completely different to evaporation from "open water".  As 
> presently coded, evaporation under ice is a bug for two reasons: first 
> because the water is removed from the wrong medium, from the water 
> rather than from the ice, and second because when evaporation is not 
> explicitly specified it is computed based on bulk formulae for open 
> water (my contribution to this bug).  So I definitely think that evap 
> needs to be masked by (1-area) without "if" or "#ifdef"
>
> How significant is evaporation from top of ice?  If it is important 
> for ice and thermodynamic budget computations then we will eventually 
> need to add it in, but correctly.
>
> Cheers, Dimitris