[MITgcm-devel] Re: empmr

[Jean-Michel Campin]

Hi Alan,

I will try to clarify some points, and cc to the devel list,
so that if I am wrong, someone will correct me:

On Thu, May 17, 2007 at 12:14:51PM -0400, Alan Condron wrote:
> Hi Jean-Michel
> 
> I just have a couple of questions about the mitgcm, concerning precip, 
> evap and empmr and seaice interactions.
> 
> Using the standard diagnostics, these arrays can be written out in 
> pkg/exf using CALL DIAGNOSTICS_FILL. However, flux adjustment over ice 
> has not occurred at this point.

You are right. Over ice-covered area, thoses flux are meaningless.

> Where can I find out how these fluxes are treated over ice?

Good question: 
- there are diagnostics of upper-ocean fluxes (air-sea fluxes
over open ocean & below the ice in ice-covered area):
individual forcings:
 oceFWflx , oceSflux , oceQnet , oceQsw , TRELAX , SRELAX ,
with some combinations:
 surForcT , surForcS , TFLUX , SFLUX

- In pkg/seaice, there is no diagnostics of the resulting surface 
atmospheric flux (total Evap or total EmP, or total Heat flux) 
that combine open-ocean flux & air-ice flux.
Such diagnostics exist in the other pkg (pkg/thsice).

> o How is precip treated over seaice?
Depends if it's snow (-> increase snow thickness) or rain
(I think rain and runoff go directly to the ocean).

> o Is evaporation over seaice simply a fraction of the cover i.e. 
> evap'=evap*(1-SIarea)?
for the full grid cell, you would need to add also the evaporation
(or better, sublimation) over sea-ice/snow.

> o How is SSSrelaxation accounted for in empmr?

relaxation is not part of EmP, treated separately, and with
a diagnostic : SRELAX

> Hope all well up at MIT!
> Alan
So nice weather today !

Cheers,
Jean-Michel