FW: [MITgcm-support] obcs for lock-exchange problem (fwd)

[samar khatiwala]

Hi Michael

Glad to hear you were able to get the OBC to work (at least partially).

> 2) cVelTimeScale
>
> after reading the code, it was determined that the filtering of the phase speed probably needed to be adjusted,so
> setting cVelTimeScale closer to deltaT changed things such that the plumes go out the boundaries now.

Yes, in the absence of some intrinsic time scale in the problem, setting
cVelTimeScale=deltaT may be your best bet. The Orlanski OB code was
originally developed for wave problems where such a time scale is easier
to identify.

> i/m still not clear as to exactly which OBCS schemes are available. any pointers?

Basically, you can have
(1) a radiation BC - only Orlanski is implemented as far as I know
(2) prescribed, including sponge, BC.

Also, there is a variant of (1) that only radiates the "wave" or variable
part of the solution by first subtracting out a mean flow. This is
probably not in the standard obcs package, but it exists if you are
interested.

Samar