[MITgcm-support] staggerTimeStep and advection scheme

[Jean-Michel Campin]

Hi Samar,

Nothing has changed since 21 Sep 2004, and regarding staggerTimeStep,
I would recommend to look at the documentation since this part
has been updated in October 2004.

In short:

> 1) When and for what quantities is staggerTimeStep used (or should be
>    used)?
quoting the documentation:
``The corresponding calling tree is given in 2.7. The staggered algorithm is
activated with the run-time flag staggerTimeStep=.TRUE. in parameter file data,
namelist PARM01''
And I can add: " ... is activated if and only if the run-time flag
staggerTimeStep=.TRUE is set in parameter file data"

> 2) Is it used only for active tracers (T/S) and velocity?
see documentation for what Synchronous time-stepping / staggerTimeStep
means. Note that passive tracers are stepped-forward within
the same S/R as active tracers, in THERMODYNAMICS.

> 3) Is it only used for advection schemes 77,33,30?
cf point 1

> 4) Does it get turned off when adams bashforth is used, since my
>    understanding is that it is there for internal wave stability.
>    (I don't see this being done in the code, though.)
>    In which case, why is it used for ptracers?
cf point 1.

if something is wrong, or not clear in the documentation, please
let us know.

Thanks,

Jean-Michel