ACE1 Model BoM GASP/HYSPLIT trajectory data from the Smart Balloon
flights have been put together into a single composite file.
The 24 separate files are demarked in the composite file by 
a Start and End message next to the original file name. 
-------------------------------------------------------------------------------
These trajectories are designed to aid in the analysis
of the balloon observations and the Lagrangian experiments. 

For Lagrangian A balloon 10 is examined.  For Lagrangian B
balloons 00, 06 and 08 are examined.  The trajectories are 
begun on locations based upon the data of Steve Businger.  
For each balloon there are six files.  

f97_B??_b5_data.dat - backwards 5-day trajectory using vertical
                      winds
f97_B??_f2_data.dat - forwards 2-day trajectory using vertical
                      winds
f97_B??_f2_isob.dat - forwards 2-day trajectory assuming an 
                      isobaric trajectory
f97_B??_f2_topl.dat - forwards 2-day trajectory using vertical
                      winds.  This trajectory is an approximate
                      UPPER limit starting at 1000m altitude. 
f97_B??_f2_botl.dat - forwards 2-day trajectory using vertical
                      winds.  This trajectory is an approximate
                      LOWER limit starting at 100m altitude. 
f97_B??_f2_COMP.dat - forwards 2-day COMPOSITE isobaric 
                      trajectory.  The pressure was readjusted 
                      hourly to match the balloon observations.  

For each series of trajectories we provide
an ASCII file which contains the time, lat, lon, pressure, U, V, vertical 
velocity in pressure, temperature, relative humidity and surface pressure. 
These fields come from the GASP data set.  

Trajectories will fail if the track hits the surface, rises above approx
500 HPa or flows off the restricted domain of the GASP data.  Also, the 
lowest interpolated GASP data is to the 0.991 omega level.  This corresponds
to roughly 110 meters height.  Trajectories below this level are not 
accurate.  Most likely they will be moving too quickly as they do not 
reflect the physics of the surface drag on the air flow.  They still provide 
a good estimate of the air motion for the first 12-24 hours.  
                      
These various trajectories were made in an effort to determine
the impact that the vertical motion of the balloon had on the 
air mass trajectory.  The differences between trajectories is not
negligible as there is strong wind shear for all days.  It is again
important to note that the GASP winds are only accurate to 
roughly 110 meters altitude.  All four balloons drop below this 
level on a number of occasions.  As a result of this, the trajectories
track more quickly than the actual balloon motion.


START of latlon.00.dat
-45.56                      #balloon 00 position at 951208 02Z
144.15
END of latlon.00.dat
 
START of latlon.06.dat
-45.56                      #balloon 06 position at 951208 03Z
144.15
END of latlon.06.dat
 
START of latlon.08.dat
-45.61                      #balloon 08 position at 951208 01Z
144.71
END of latlon.08.dat
 
START of latlon.10.dat
-44.97                      #balloon 10 position at 951201 13Z
141.10
END of latlon.10.dat

Please contact steve siems (s.siems@sci.monash.edu.au) 
regarding questions.