Hi Tony,

I've been looking at the Lare3d code structure to implement a time dependent
driving of say Alfven wave components vy(:,:,nz/2) and by(:,:,nz/2) (with B0
along z-axis) in the mid-z plane. Could you please provide some advice what
would be the best way of doing this? (I trust initial_conditions routine is
read only once at t=0).

would it then be OK to add some lines in the following main loop in
src/core/lare3d.f90

DO
    IF ((i >= nsteps .AND. nsteps >= 0) .OR. (time >= t_end)) EXIT
    i = i + 1
    CALL eta_calc                    ! lagran.f90
    CALL set_dt                      ! diagnostics.f90  
   
vy(1:nx,1:ny,nz/2)= some_function(time)
by(1:nx,1:ny,nz/2)= some_function(time)

    CALL lagrangian_step             ! lagran.f90
    CALL eulerian_remap(i)           ! remap.f90
    IF (rke) CALL energy_correction  ! diagnostics.f90
    IF (any_open) THEN
      CALL open_bcs                  ! openboundary.f90
    END IF                 
    CALL output_routines(i)          ! diagnostics.f90
  END DO

Many thanks in advance.

David