C**********************************************************************
C     JTR - MAX NUMBER OF STEPS IN TRAJECTORY INPUT FILE (50 PER DAY)
C     NJTR - ACTUAL NUMBER OF STEPS IN TRAJECTORY FILE
C     TRTIME - TRAJECTORY STEP TIME IN JULIAN DAY FRACTION
C     TRLAT - LATITUDE OF AIR PARCEL ON TRAJECTORY
C     TRPRES - PRESSURE OF AIR PARCEL ON TRAJECTORY
C     TRTEMP - TEMPERATURE OF AIR PARCEL ON TRAJECTORY
C     TRPV - POTENTIAL VORTICITY OF AIR PARCEL ON TRAJECTORY
C     TRPT - POTENTIAL TEMPERATURE OF AIR PARCEL ON TRAJECTORY
C     TRSZA - SOLAR ZENITH ANGLE OF AIR PARCEL ON TRAJECTORY
C     TRPAR - NUMBER OF PARCELS AVERAGED AT EACH PT LEVEL
C     TRLONG - LONGITUDE OF AIR PARCEL ON TRAJECTORY
C     ITMONTH - STARTING MONTH IN BACK TRAJECTORY
C     ITDAY - STARTING DAY IN BACK TRAJECTORY
C     LEVP - PRESSURE LEVEL TO BE SUBSTITUTED WITH TRAJECTORY'S PRESSURE
C**********************************************************************
      PARAMETER (JTR=600)
Cgal      REAL*8 TRTIME(JTR)
      REAL*4 TRTIME(JTR)
      REAL*4 TRLAT(JTR),TRPRES(JTR),TRTEMP(JTR),TRPV(JTR),
     + TRPT(JTR),TRSZA(JTR),TRLONG(JTR)
      INTEGER TRPAR(JTR),LEVP

      COMMON/TRAJ/NJTR,TRTIME,TRLAT,TRPRES,TRTEMP,TRPV,TRSZA,
     +  TRPAR,TRLONG,TRPT,LEVP
      COMMON/TRDATE/ITMONTH,ITDAY