1) Is the cppdefs option TS_U3ADV_SPLIT something similar to what is described here:
Marchesiello, P., Debreu, L., Couvelard, X. 2009. Spurious diapycnal mixing in terrain-following coordinate models: The problem and a solution. Ocean Modelling 26, 156-169.
http://www.myroms.org/Workshops/ROMS201 ... emarie.pdf ?
2) If I choose TS_U3ADV_SPLIT globaldefs will have me use
But Hernan has mentioned in this forum:
Do Hernan's suggestions take care of spurious diapycnal mixing in sigma-coordinates in a different way?I have also recommended in all ROMS workshops to use TS_A4HADVECTION and TS_A4VADVECTION with explicit diffusivity (TS_DIF2 and MIX_TS_GEO). For vertical advection of momentum you should useUV_C4VADVECTION.
Just try the recommendation and compare the solutions. Then, you will know what I am talking about. This is the best advice that I can give to any ROMS user...
It would seem that mixing TS along isopycnals would be more physical (at least for a baroclinic ocean) than along geopotentials ...
3) Any suggestions and guidance regarding this topic are very welcome. I would like to be able to reproduce a warm and salty tongue of water moving over the slope where isopycnals are sloping up above the tongue and sloping down below it.