!--------------------------------------------------------------------------
   !---------------------------- remap_u ----------------------------------
   ! IN : u, old_rhodz, rhodz, eta
   ! TMP : urhodz_cum, new_urhodz_cum
   ! OUT : u
   !$OMP DO SCHEDULE(STATIC)
   DO edge=1,edge_num
      ij_left = left(edge)
      ij_right = right(edge)
      urhodz_cum(1,edge)=0.
      DO l = 1,llm
         urhodz(l,edge) = u(l,edge)*(old_rhodz(l,ij_left)+old_rhodz(l,ij_right))
         urhodz_cum(l+1,edge) = urhodz_cum(l,edge) + urhodz(l,edge)
      END DO
      DO l = 1,llm+1
         X = .5*(eta(l,ij_left)+eta(l,ij_right))
         level = MIN(llm,FLOOR(X))
         X = X-level
         new_urhodz_cum(l,edge) = urhodz_cum(level,edge)+X*urhodz(level,edge)
      END DO
      DO l = 1,llm
         u(l,edge) = (new_urhodz_cum(l+1,edge) - new_urhodz_cum(l,edge)) / (rhodz(l,ij_left)+rhodz(l,ij_right))
      END DO
   END DO
   !$OMP END DO
   !---------------------------- remap_u ----------------------------------
   !--------------------------------------------------------------------------