SUBROUTINE kg_to_cm3(pplay,t_seri,tr_seri)
  !
  USE dimphy
  USE infotrac
  USE dimensions_mod, ONLY: iim, jjm, llm, ndm
USE yomcst_mod_h, ONLY: RPI, RCLUM, RHPLA, RKBOL, RNAVO                   &
          , RDAY, REA, REPSM, RSIYEA, RSIDAY, ROMEGA                  &
          , R_ecc, R_peri, R_incl                                      &
          , RA, RG, R1SA                                         &
          , RSIGMA                                                     &
          , R, RMD, RMV, RD, RV, RCPD                    &
          , RMO3, RMCO2, RMC, RMCH4, RMN2O, RMCFC11, RMCFC12        &
          , RCPV, RCVD, RCVV, RKAPPA, RETV, eps_w                    &
          , RCW, RCS                                                 &
          , RLVTT, RLSTT, RLMLT, RTT, RATM                           &
          , RESTT, RALPW, RBETW, RGAMW, RALPS, RBETS, RGAMS            &
          , RALPD, RBETD, RGAMD
IMPLICIT NONE
  !


  !
  REAL :: t_seri(klon,klev), pplay(klon,klev)
  REAL :: tr_seri(klon,klev)
  REAL :: zrho
  INTEGER :: i, k
  !
  DO k = 1, klev
  DO i = 1, klon
    zrho=pplay(i,k)/t_seri(i,k)/RD
    tr_seri(i,k)=tr_seri(i,k)/1.e6*zrho
  ENDDO
  ENDDO
  !
END SUBROUTINE kg_to_cm3