i have a question about nudging coefficient.

[kobl1201]

hello

when i run ROMS model using nuding scheme, i want to change nudging coefficient.

At that time, i have a question. how much is the range of the coefficient??

now, the roms model was set like this

DO j=JstrV,Jend
DO i=Istr,Iend
cff=0.25_r8*(CLIMA(ng)%M3nudgcof(i,j-1,k)+ &
& CLIMA(ng)%M3nudgcof(i,j ,k))* &
& om_v(i,j)*on_v(i,j)
rv(i,j,k,nrhs)=rv(i,j,k,nrhs)+ &
& cff*(Hz(i,j-1,k)+Hz(i,j,k))* &
& (CLIMA(ng)%vclm(i,j,k)- &
& v(i,j,k,nrhs))


when what do the variables, om_v and on_v, mean??

[kate]

om_v is like delta-x on v points while on_u is like delta-y on u points. The product of on_v and om_v is the area of a grid cell centered on a v point.

You can set those nudging coefficients to whatever you think makes sense. We usually set them to zero, except maybe in a band around the boundary.

[kobl1201]

i have a question one more.

cff is nudging coefficient or not??

what is the nudging coeficient ??

[kate]

The nudging coefficients are CLIMA(ng)%M3nudgcof and friends. Hernan now recommends that you set them externally, through Matlab or whatever, then read them into ROMS. The units there are in days, then ROMS scales them appropriately for its internal use.