SUBROUTINE kg_to_cm3(pplay,t_seri,tr_seri)
  !
  USE dimphy
  USE infotrac
  IMPLICIT NONE
  !
  INCLUDE "dimensions.h"
  INCLUDE "YOMCST.h"
  !
  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