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