!--------------------------------------------------------------------------
   !---------------------------- caldyn_wflux ----------------------------------
   DO l = llm-1,1,-1
      !DIR$ SIMD
      DO ij=ij_omp_begin,ij_omp_end
         ! cumulate mass flux convergence from top to bottom
         convm(ij,l) = convm(ij,l) + convm(ij,l+1)
      END DO
   END DO
   !DIR$ SIMD
   DO ij=ij_omp_begin,ij_omp_end
      dmass_col(ij) = convm(ij,1)
   END DO
   DO l = 2,llm
      !DIR$ SIMD
      DO ij=ij_omp_begin,ij_omp_end
         ! Compute vertical mass flux (l=1,llm+1 set to zero at init)
         wflux(ij,l) = mass_bl(ij,l) * dmass_col(ij) - convm(ij,l)
      END DO
   END DO
   ! make sure wflux is up to date
   !$OMP BARRIER
   !---------------------------- caldyn_wflux ----------------------------------
   !--------------------------------------------------------------------------