[MITgcm-support] DST3 advection scheme

[samar khatiwala]

Hi Jean-Michel

Thanks for responding so quickly. (Who else would on a Sunday afternoon!)
This is exactly the answer I was looking for.
Just to confirm, are you suggesting I change:

        thetaP=Rjm/(1.D-20+Rj)
to
        thetaP=Rjm/Rj

and
        thetaM=Rjp/(1.D-20+Rj)
to
        thetaM=Rjp/Rj

Yes, that would reproduce the equations in the documentation and make the
scheme linear in the tracer concentration. Just what I wanted.

Thanks, Samar

On Sun, 11 Jan 2004, Jean-Michel Campin wrote:

> Hi Samar,
>
> > However, looking at the source in gad_dst3_adv_x.F I am no longer certain.
>
> Apart from the 1.d-20 (which I don't like too much because for
> some biological tracer, e.g. iron or others, the usual concentration
> can be very small also, and the chance to get Rj equal -1.D-20 is not
> zero) that I guess you can remove (because thetaM & P are allways *Rj
> after),
> the scheme looks like it should, linear regarding the tracer, but non
> linear regarding the flow field. Is this answering your question ?
>
> See you,
>
> Jean-Michel
>