[MITgcm-support] High vertical velocity/noise next to land

[Martin Losch]

Hi David,

good question. 
I think ISOTROPIC_COS_SCALING should be defined ISOTROPIC_COS_SCALING, but make shure that is only applies to the gad_*.F files (-> GAD_OPTIONS.h), and not the mom_*.F files.
In an effort to reduce the horizontal diffusion as much as possible, I usually set diffKh/4T/S so zero and use an unconditionally stable advection scheme (such as 33).

Martin

On Jan 28, 2010, at 1:10 PM, David Munday wrote:

> 'm experimenting with the viscAhgrid and viscA4grid parameters at the moment, although it looks like I might need values as small as 0.05 to give comparable viscosity/diffusivity to the constants that I was prescribing before. I suspect that friction/dissipation, and time step, might still need some tuning. If I'm using diffK4T & diffK4S to set biharmonic coefficient for temperature and salinity, do I then need to define ISOTROPIC_COS_SCALING in GAD_OPTIONS.h to ensure that it's scaled properly?