[MITgcm-devel] Unrealistic low SST with SEAICE_GROWTH_LEGACY undef

[Menemenlis, Dimitris (3248)]

Gael, thanks for comments.  Some answers below:

Regarding the name, I can use "pkg/interior_freeze" for package but need
a shorter name (ifreeze?) for flags, variable names, and subroutine names.

I agree that this package need to work independently of the other ice packages.
Modifying any of the sea ice packages is a separate step.
What Ian and I envisioned is following sequence:

1. Call iFREEZE_INTERIOR
    to adjust interior temperature to freezing point and to compute negative heat anomaly that rises to surface.

2. Call all the other ice package (freeze_surface, seaice, thsice, icefront, shelfice, ...)
    which can (but do not have to) operate on this negative heat anomaly.

3. Call iFREEZE_SURFACE
    which will use any residual negative heat left over after the other ice packages are done,
    to cool SST or sea water immediately below ice shelves.

The above sequence will achieve what you describe below, but it leave open the possibility for
the ice packages to do fancier stuff with this negative heat anomaly, if they wish to do so.

Dimitris Menemenlis

On Feb 15, 2012, at 8:26 AM, Gael Forget wrote:

Hi Dimitris,

I dont have a strong preference regarding names but interior_freeze may be
just fine (item 1) and item 3 likely should be done before anything else.

As far as item 2 the new package should be made to work independently of pkg/thsice and pkg/seaice first (and of kpp please).
Basically I suggest you start with
=> A 2D array containing negative heat in "Joules" will be generated that will be added to Qnet.
=> allowFreezing rather than more complex ice models, and convective adjustement rather than kpp.
It would be nice to add a switch to decide whether the needed heat should be taken from the ocean first layer (as it is now I believe)
or in the atmosphere (where your plan takes at least some of it). And it should be possible for the user to back out the
ocean conservation of heat (or the lack thereof) using pkg/diagnostics. Those points seem like obvious pre-requisites
to a discussion of whether a refined integration in ice models is worth it and of interest. If you decide to forego those intermediate steps,
I would suggest you go all the way and start with pkg/thsice rather than pkg/seaice -- with the better ice conservation principle that is.

Cheers,
Gael

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