!--------------------------------------------------------------------------
   !---------------------------- remap_eta ----------------------------------
   ! IN : rhodz, mass_dak, mass_dbk
   ! TMP : mass_col, cur_lev, new_rhodz_cum
   ! OUT : rhodz, old_rhodz, eta
   !$OMP DO SCHEDULE(STATIC)
   DO ij=1,primal_num
      rhodz_cum(1,ij)=0.
      cur_lev(ij)=1
      eta(1,ij)=1.
      new_rhodz_cum(ij)=0.
      DO l = 1,llm
         rhodz_cum(l+1,ij) = rhodz_cum(l,ij) + rhodz(l,ij)
      END DO
      mass_col(ij) = rhodz_cum(llm+1,ij)
      DO l = 1,llm
         old_rhodz(l,ij) = rhodz(l,ij)
         rhodz(l,ij) = mass_dak(l,ij) + mass_col(ij)*mass_dbk(l,ij)
         rhodz_cum_target = new_rhodz_cum(ij) + rhodz(l,ij)
         DO level = cur_lev(ij), llm
            rhodz_cum_levp1 = rhodz_cum(level+1,ij)
            IF(rhodz_cum_target<=rhodz_cum_levp1) EXIT
         END DO
         IF(level>llm) level=llm
         rhodz_cum_lev = rhodz_cum(level,ij)
         ! now rhodz_cum_lev <= rhodz_cum_target <= rhodz_cum_levp1
         cur_lev(ij) = level
         new_rhodz_cum(ij) = rhodz_cum_target
         eta(l+1,ij) = level + (rhodz_cum_target-rhodz_cum_lev)/(rhodz_cum_levp1-rhodz_cum_lev)
      END DO
   END DO
   !$OMP END DO
   !---------------------------- remap_eta ----------------------------------
   !--------------------------------------------------------------------------