How to define some parameters of *.in file?

[rainbowbluegz]

hi,
I am confused about the following parameters in *.in file:

! Harmonic/biharmonic horizontal diffusion of tracer for nonlinear model
! and adjoint-based algorithms: [1:NAT+NPT,Ngrids].

TNU2 == 0.0d0 0.0d0 ! m2/s
TNU4 == 2.0d0 2.0d0 ! m4/s

ad_TNU2 == 0.0d0 0.0d0 ! m2/s
ad_TNU4 == 2.0d0 2.0d0 ! m4/s

! Harmonic/biharmonic, horizontal viscosity coefficient for nonlinear model
! and adjoint-based algorithms: [Ngrids].

VISC2 == 0.0d0 ! m2/s
VISC4 == 4.0d0 ! m4/s

ad_VISC2 == 0.0d0 ! m2/s
ad_VISC4 == 4.0d0 ! m4/s

How to define the TNU2, TNU4,ad_TNU2, ad_TNU4,VISC2,VISC4, ad_VISC2, ad_VISC4? if the case is with resolution of 1/7 degree for coastal ocean. or what references I should see? Thanks a lot!

[kate]

Some things to consider are here