May 04, 1996

Mission Summary

DC-8 SUCCESS flight #214 [960214] (scientists: Brian Toon and Eric Jensen)

SUMMARY: The basic flight went very well (less people got sick). Contrails were more persistent with than the day before. Combined contrail and radiation mission, which included the DOE Egret and Otter. NOAA satellite overpass.

Mission Objective

• sample the near field exhaust behind the 757 with DC-8 and T-39
• photograph (T-39) differences in contrails with different sulfur levels (the T-39 will remain within 2 miles of the 757, and will offset periodically to lower altitude)
• study (DC-8) the in situ chemistry and microphysics of the 757 contrail (the DC-8 will be 5-10 miles behind the 757 and several hundred feet below it - the lidar will be used only in forward or downward scanning mode when more than 8 miles behind the 757 and cannot be used in the vertical mode due to the ER-2)
• investigate (ER-2, DC-8, T-39) the radiative properties of the contrails created by the 757 during

Flight Track

Flight Log

OPERATIONS
FLIGHT PLAN:
The flights should take about 5 hours. Take off is planned for 17.00 UT (local noon). We will stager the takeoff with the ER-2 going first, followed by the 757 and the DC-8, the T-39 will follow about 1.5 hours later.. All the aircraft will proceed to the CART site to an altitude of 39kft or as high as possible. The DC-8 will fly three oval tracks, each one hour in duration, at as high an altitude as possible. Then it will pass directly over the CART site.
The DC-8 will be 5-10 miles behind the 757 and about 300 ft.

• L-L: 757 burns low sulfur fuel in left engine and low sulfur fuel in right engine
• H-L: 757 burns high sulfur fuel in left engine and low sulfur fuel in right engine
• H-H: 757 burns high sulfur fuel in left engine and high sulfur fuel in right engine

TAKEOFF/LANDING
The DC-8 left Salina at 17.25 UTC (12.25 noon time) and returned to Salina at 22.15 UTC

FLIGHT REPORT
We flew the planned pattern over the CART site.

METEOROLOGY-REPORT
OBSERVATIONS: We were not able to make persistent contrails, but we could make some contrails in excess of 10 miles (especially during the middle of the mission). Low level fair weather cumulus was present for most of flight.

INSTRUMENT STATUS
The Hudson CCN counter failed before takeoff.
Probe selection: FSSP 300, MASP, replicator and cloud scope.

• BALLENTHIN: No data.
• BAUMGARDNER: Worked fine.
• BRUNE: Worked fine.
• CHAN: Worked fine.
• COGGIOLA: Worked fine.
• COOPER: Worked fine.
• DADS: Worked fine.
• FERRY: Worked fine.
• GARY: Worked fine.
• GERBER: Failed.
• HAGEN: Worked fine.
• HALLET: Worked fine.
• HEYMSFIELD: Worked fine.
• HUDSON: Failed before take off, may not be able to fix.
• LAWSON: Worked fine.
• RODGERS: Worked fine.
• SACHSE: Worked fine.
• TALBOT: Worked fine.
• TWOHY: Worked fine.
• UTHE: Worked fine.
• VALERO: Worked fine.
• WEINHEIMER: Worked fine.

Mission Highlights

• anti-correlation was found beween OH and HO2 in contrails
• contrail particles were small and did not have an obvious crystal habit
• contrail particles seemed more thermally stable than ice (slower evaporation)
• ice crystals seemed to be growing between 5 and 10 miles behind the 757
• the CART site lidar sampled the embarking DC-8 contrail four times (1.5m vertical resolution
• different contrail colors for T-39 (shade of brown) and 757 (shade of blue) were observed from the ground. The 757 burned low sulfur fuel at that time. (This indicates that contrail particles from high sulfur fuel burn are - initially - smaller and more numerous).