!--------------------------------------------------------------------------
   !---------------------------- compute_vorticity ----------------------------------
   DO l = 1, llm
      !DIR$ SIMD
      DO ij=ij_begin_ext, ij_end_ext
         etav = 0.d0
         etav = etav + ne_rup*ue(ij+u_rup,l)*de(ij+u_rup)
         etav = etav + ne_left*ue(ij+t_rup+u_left,l)*de(ij+t_rup+u_left)
         etav = etav + (-ne_lup)*ue(ij+u_lup,l)*de(ij+u_lup)
         vort(ij+z_up,l) = etav / Av(ij+z_up)
         etav = 0.d0
         etav = etav + (-ne_rdown)*ue(ij+u_rdown,l)*de(ij+u_rdown)
         etav = etav + ne_right*ue(ij+t_ldown+u_right,l)*de(ij+t_ldown+u_right)
         etav = etav + ne_ldown*ue(ij+u_ldown,l)*de(ij+u_ldown)
         vort(ij+z_down,l) = etav / Av(ij+z_down)
      END DO
   END DO
   !---------------------------- compute_vorticity ----------------------------------
   !--------------------------------------------------------------------------