Michael Biggerstaff, Aircraft Mission Coordinator (TRMM OPS)

Peter Hobbs, Convair Chief Scientist

Tony Grainger, Citation Chief Scientist

Michael Goodman, DC-8 Chief Scientist

______________________________________________________________________

Aircraft Mission Coordinator Summary
______________________________________________________________________

Mission Summary for 12-13 September 1999 UTC, 13 September local
This is the only mission flown this day.
All times below are UTC
Single aircraft mission: DC-8
DC-8 t/o ~2215, landed ~0045 (not exact)
TRMM OVERPASS: None

The weather was nearly perfect for a clear air experiment with the scanning HIS instrument. The only precipitation within quantitative radar range was an fairly isolated shower near Roi Namur. The goal of the mission was to collect data needed to validate HIS water vapor retrievals. Rawinsondes were released at Kwajalein, Lae, and Roi Namur at 2300 UTC. The DC-8 climbed to altitude (~38K ft) and performed race-track patterns around the rawinsonde stations. Initially two ~20 km straight legs were flown about 10 miles on either side of the site locations. Precipitation near Roi Namur resulted in an initial pass that was a little farther away from the site than the passes made at Kwajalein and Lae.

A second circuit was made around the islands with one straight leg near the site. After that, the aircraft attempted to find thin cirrus at low enough altitude for the scanning HIS cirrus experiment. Suitable cirrus was unavailable, so the aircraft returned to base.

______________________________________________________________________

DC-8 Chief Scientist Summary
______________________________________________________________________

DC-8 Mission Science Summary

Flight: 990537
=20 Date: 12 Sep 99 Julian Day 255
Take Off: 221716 UTC (Julian Day 255)
Touch Down: 005332 UTC (Julian Day 255)
Flight Length: 2.7 hours
Flight Hours Remaining: 6.4 hours
Mission Scientist: Michael Goodman

=20 AMPR scientist: Richard Wohlman
=20 ARMAR scientist: Steve Dinardo
CPP scientist: David Kingsmill
SHIS scientist: Dave Tobin
CPI scientist: not flying because no operator available and the science = objective was to fly clear air.

Unanticipated Instrument Down Time During Flight
ARMAR: no down time
=20 AMPR: no down time
=20 CPP: no down time (2DP probe and FSSP not on the plane; only 2DC and = video were operating)
CPI: not operating
=20 S-HIS: no down time

Primary Objective: There was a TRMM overpass today at 1959 UTC, but = precipitation weather was not=20 present, so the DC-8 flew a clear air mission to validate Scanning HIS = water vapor retrievals.
Narrative:
At takeoff time the radar showed no precipitation in range. = The DC-8 flight plan called for flybys of the Kwajalein, Lae, and Roi Namur rawinsonde launch sites = timed to coincide with the each balloon's ascent to altitude. The rawinsonde launches were staggered by = 10 minutes to allow for the=20 DC-8 transit time between each site. The Kwajalein launch was scheduled = for 2300 UTC, Lae launch for 2310 UTC and the Roi Namur launch for 2320 UTC. The DC-8 ascended to 39,000 ft = and and initially flew a racetrack=20 around the Kwajalein site in preparation for the 2300 UTC rawinsonde = launch. The DC-8 flight plan called for 20 km straight line passes at a 10 km distance abeam of each site.

=20 Kwajalein pass 1 (NW-SE) was conducted from approximately 2255 - 2257 = UTC and pass 2 (SE-NW) was flown from approximately 2301 - 2303 UTC. The DC-8 then headed for the Lae = site and completed pass 3 (E-W)=20 from 2314-2316 UTC. The DC-8 looped around Lae and flew west to east = from approximatley 2320-2322 UTC=20 completing pass 4. The DC-8 then flew towards Roi Namur but had to = deviate around some isolated=20 precipitation in order to stay in clear air. Pass 5 (NW-SE) was = completed from 2337-2339 UTC. The DC-8 then headed back to Kwajalein this time flying a N-S leg (pass 6) = from 2344-2347 UTC. The DC-8 then=20 turned back towards Lae and completed pass 7 from 0001-0003 UTC. = Finally the DC-8 flew back toward Roi=20 passing to the south of it at 0017-0019 UTC (pass 9).
With the sounding flybys completed the DC-8 then briefly searched for a = suitable deck of cirrus to fly over, through, and under. However, their was none to be found so = the DC-8 returned to base.
The flight today was successful with excellent timing of the DC-8 flying = by the rawinsonde sites within 10-20 minutes of the projected time of the balloons reaching the = 39,000 ft altitude. The AMPR instrument also collected necessary clear air ocean scenes for = calibration. The CPP operated but there were no clouds to sample, and ARMAR never collected data since = there was no precipitation in the area.
Post-Flight Instrument Status:
=20 ARMAR: ready to fly the next mission
AMPR: ready to fly the next mission
CPP: 2DC laser and video probes are ready to fly. The 2DP and FSSP will = not fly.
CPI: ready to fly the next mission
SHIS: ready to fly the next mission
=20 Michael Goodman
=20 DC-8 Mission Scientist