Hello ROMS users,
Excuse my ignorance, but I would like to know how u and v baroclinic velocities are defined or specified in ROMS? Is this the total u and v minus u or v_barotropic or this is the total minus the depth averaged. The difference should not be much, but I’d like to know this.
Thank you!
Rafael
how is it define baroclinic velocity in ROMS?
Re: how is it define baroclinic velocity in ROMS?
The roms u,v are the total velocity. They are synchronized with the barotropic ubar,vbar each (baroclinic) timestep by computing the depth average, subtracting it, then adding in ubar,vbar.
The ubar, vbar in this context are time averaged from many little steps, weighted to be centered in time at the new time. See Sasha Shchepetkin's papers for all the details.
The ubar, vbar in this context are time averaged from many little steps, weighted to be centered in time at the new time. See Sasha Shchepetkin's papers for all the details.
Re: how is it define baroclinic velocity in ROMS?
how is it define baroclinic velocity: for practical purposes it is simply
where u,v_bcl(i,j,k) are baroclinic velocities;
u,v(i,j,k,nstp) are ROMS 3D velocities at certain time step as they occur in ROMS output history file;
ubar,vbar(i,j,nstp) are barotropic velocities at the same time step as in output file (they are already
fast-time averaged within the code).
Code: Select all
u_bcl(i,j,k)=u(i,j,k,nstp)-ubar(i,j,nstp)
v_bcl(i,j,k)=v(i,j,k,nstp)-vbar(i,j,nstp)
u,v(i,j,k,nstp) are ROMS 3D velocities at certain time step as they occur in ROMS output history file;
ubar,vbar(i,j,nstp) are barotropic velocities at the same time step as in output file (they are already
fast-time averaged within the code).