DC-8 SUCCESS flight #218 [960218] (scientists: Brian Toon and Jim Spinhirne)
SUMMARY: The basic flight went very well.
OPERATIONS
FLIGHT PLAN:
1. Take off: 13:00 LT (2000 UT) planned.
2. The first leg is from Ames to the North ending at the edge of
Oakland airspace. We have requested an altitude of 20 kft on this leg so that
we can perform low altitude manuevers to calibrate the MMS. We plan to
operate the SRI lidar on this legs in a vertical position, to learn the
altitudes of any cirrus.
3. Once the MMS calibration is finished we will fly the DC-8 on a race track
pattern aligned to the wind (230 at 50 knts.) The race track will take about
20 minutes to go all the way around. Assuming the cirrus is not too thick we
will make 4 loops spaced 2000 ft apart in altitude through the cloud. We will
then profile back down in the same manner. If persistent contrails form we
may ask that the second leg of the racetrack at maximum altitude go back down
the first leg so that we can sample the contrails. The lidar will be used in
a forward scanning mode during this time. We will continue this general
pattern until 1800 LT. On one of the high altitude legs we will do another
box pattern for the MMS.
4. One the transit back to Ames we will perform roll and yaw manuevers for MMS
at the same
altitude that the box was flown.
TAKEOFF/LANDING
The DC-8 left Ames at 20.00 UTC (13.00 noon local time) and
returned to Ames at 01.40 UTC
FLIGHT REPORT
Cirrus clouds were present over the Pacific near the Oregon - California
border. However, only a small strip of water near the coast was not covered
by stratus. We were not able to use this strip of stratus-free water very
well because of coastal air traffic. We therefore decided to use the flight
to investigate long lived contrails. We flew an oval pattern taking about
twenty minutes to complete one loop. On the next loop we remained within our
old contrail for the entire loop. We performed manuevers above and below the
contrails to investigate their radiative properties, and we passed through the
contrails many times to investigate their microphysics. These contrails
contained large (100 um) ice crystals. Active precipitation was observed from
the contrails. These were the most persistent contrails observed during
SUCCESS. We did complete the MMS calibration manuevers.
METEOROLOGY-REPORT
OBSERVATIONS:
Less favorable conditions for the major objective at the target region - with
most of the coastal waters covered by stratus.
INSTRUMENT STATUS
The impactors are not present on the nose so that a calibration of MMS can be
done without them.
Otherwise all instruments are functioning.