[MITgcm-support] Turning off the ocean

[Jean-Michel Campin]

Hi Chris,

if you try:
 momStepping=.FALSE.,
in file "data", 1rst namelist ( PARM01 ), this will prevent any update of 
the velocity field that will remain the same as initial condition.

If you prefer to prescribe a time-dependent velocity field then you could
use pkg/offline (some doc in the manual & example: verification/tutorial_cfc_offline).

There is no run-time switch to turn off active tracer (T,S) diffusivity
other than to set various diffusivity coeff to zero.
But by using:
>  saltAdvection = .FALSE.,
>  tempAdvection = .FALSE.,
this should turn off the advection.

I don't know why the model was becoming unstable, may be too large time-step
relative to viscosity/diffusion/coriolis ?

Cheers,
Jean-Michel

On Fri, Jan 13, 2017 at 01:07:23PM -0500, Chris Horvat wrote:
> Hey all,
> 
> I'd like to compare simulations with and without a dynamically active
> ocean, but keeping the thermodynamic component. I've tried a couple of
> methods that become unstable.
> 
> First I tried:
> 
>  saltAdvection = .FALSE.,
>  tempAdvection = .FALSE.,
> 
> Which has worked for me in the past, but now goes unstable. So then I did
> some more digging, and now set.
> 
> momForcing = .FALSE.,
> momAdvection = .FALSE.,
> 
> But this also goes unstable after a while. Is there a way to totally turn
> off the ocean momentum equations? I am using KPP + Smagorinsky viscosity.
> Haven't turned them off yet in these unstable simulations as I am nervous
> that this might introduce new issues.
> 
> Chris

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