[MITgcm-support] Sponge BCs and passive tracers?

[Sonya Legg]

Dear mitgcmers,

I'm trying to see if it is possible for me to include passive tracers 
with sponge boundary conditions. I'm setting up a regional calculation 
which I have previously done two different ways:

1. open bcs with Orlanski on 3 sides, forced inflow on 1 side, including 
a passive tracer in the inflow

2. open bcs with sponge on all 4 sides, no passive tracer

Now I would like to include a passive tracer in variant 2, but I think 
maybe passive tracer can't be included in sponge boundaries (at least I 
can't see any code that suggests it is...)

Let me know if I am wrong, and there is a way to do it...

Thanks!

Sonya