[MITgcm-support] Uniform diffkrfile

[Dimitris Menemenlis]

Geof, do you "#define ALLOW_3D_DIFFKR" in CPP_OPTIONS.h?
If not, the diffKrFile variable will be ignored.
In ini_mixing there is the following code:

> #if (defined ALLOW_3D_DIFFKR || \
>      (defined (ALLOW_AUTODIFF_TAMC) && defined (ALLOW_DIFFKR_CONTROL)))
>        IF ( diffKrFile .NE. ' ' ) THEN
>           CALL READ_FLD_XYZ_RL(diffKrFile,' ',diffKr,0,myThid)
>        ENDIF
>       _EXCH_XYZ_R8(diffKr , myThid )
> #endif

I can add a check in config_check.F if helpful.

D.


> I am running an experiment using the 3D diffusivity file, and I've got some problems : I have some strong velocities when I use the diffkrfile.
> So I tried to see what happened if using a uniform diffkrfile.
> 
> When I try to run an experiment with the following parameters :
>  viscAh=0.1,
>  viscAz=0.1,
>  diffKhT=0.1,
>  diffKzT=0.,
>  diffKhS=0.1,
>  diffKzS=0.,
> and a diffkrfile with a uniform 1.E-5 m2.s-1, I get some instabilities very quickly.
> 
> If I try with :
>  viscAh=0.1,
>  viscAz=0.1,
>  diffKhT=0.1,
>  diffKzT=1.E-5,
>  diffKhS=0.1,
>  diffKzS=0.,
> and no diffkrfile, the situation is stable
> 
> And if I try with
>  viscAh=0.1,
>  viscAz=0.1,
>  diffKhT=0.1,
>  diffKzT=1.E-5,
>  diffKhS=0.1,
>  diffKzS=1.E-5,
> and no diffkrfile, the situation is no more stable.
> 
> I did try to change the code to see if it had something to do with the salinity (which is 35ppm everywhere in my experiment), but it doesn't seem to be the good option.
> On this web page, you can find some more information about my configuration (pictures).
> http://perso.crans.org/gaubry/dossier/stage/index.html#bug
> 
> The question is : do you know how to use the diffkrfile so that when it is uniform you get the same than when you change the diffusivity for the whole map? Once done, I suppose that I will be able to use it non uniform...
> T