c
c=======================================================================
c  Include file "tracktime.h"
c=======================================================================
c
#ifndef rmdocinc
c  DTSTEP   size of tracer timestep (days).
c  ISTEP    interval of integration.
c  IWUP     pointer to compute vertical velocity.
c  NSTEP    number of time integration steps per model timestep.
c
c=======================================================================
c
#endif
      common /itracktime/ istep,nstep,iwup
      integer istep,nstep,iwup
c
      common /ftracktime/ dtstep
      FLOAT 
     *      dtstep