SUCCESS 04/18/96 Mission Daily Schedule

The DC-8 sampled the T-39 exhaust plume without contrails. The DC-8 also detected a weak tropopause fold. The T-39 provided emissions for the DC-8 to sample and also sampled the DC-8 emissions. The T-39 was able to fly at a fixed position (20-50 meters behind the DC-8) and sample the exhaust of the individual inboard engines.

Highlights

Flight Reports

Mission Summary

DC-8 SUCCESS flight #205 [960205] (scientist: Eric Jensen)

SUMMARY: The basic flight went very well. All of the instruments are functioning, with some small problems left to be worked out. We sampled the T-39 exhaust plume under conditions with no contrails, which was one of our major objectives. We also sampled the tops of some mid-level cirrus and the tops of generating cells near the limit for water drop homogeneous freezing.

Mission Objective

The climbout portion of the flight (Part 1) will allow the T-39 to sample the DC-8 exhaust. The transient contrail sampling should provide data on exhaust microphysical properties and chemical composition and young contrail microphysical properties. This flight should also clarify the dependence of transient contrail lifetime on environmental conditions. Finally, we will investigate the impact of contrail processing on plume chemistry and microphysical composition.

Flight Track

Flight Log

FLIGHT PLAN:
Part 1: Formation flying to target
After rendezvous at 20kft, T-39 follows DC-8 to the cart site. The aircraft will fly level stairstep legs at 20, 25, and 35kft, with the T-39 sampling the DC-8 exhaust.
Part 2: Sampling Transient Contrails and Exhaust
Once on station, the aircraft will ascend to 31kft and the DC-8 will drop behind the T-39. The DC-8 will follow the T-39 in a racetrack pattern with 15 min. legs (100 mi.) aligned with the wind at 31kft. 2 circuits will be flown at each of 2 altitudes: 31 and 35kft. The second circuit at each altitude will be offset 12 miles to avoid sampling of old plume from the first circuit. The 4 legs will be flown with different separation between the aircraft:
Leg 1: As close as possible
Leg 2: 2 mi.
Leg 3: 4 mi.
Leg 4: 6 mi.
The separation on leg 4 should be large enough such that the contrail has dissipated before the DC-8 reaches it. The DC-8 will need to pitch and roll slightly to make sure entire contrail/plume is sampled by all instruments.
The ER-2 will fly a similar racetrack pattern above the DC-8/T-39 track with two important difference: First, the ER-2 heading will be reverse relative to the DC-8/T-39; second, the ER-2 racetrack will be inclined about 10 deg. to the DC-8/T-39 track. The 3 aircraft should coordinate to reach intersection waypoints such that the ER-2 crosses between the two lower aircraft, thus sampling the TR-9 contrail before the DC-8 flies through it. This will require precise timing of waypoint crossings (within 1 min.). The reverse-heading flight path of the ER-2 gives the MAS a better chance of hitting contrail. The coordinated overpasses will occur at the CART site on legs 2 and 4 of each circuit.

TAKEOFF/LANDING
The DC-8 left Salina at 17.01 UTC (12.01 am local time) and returned to Salina around 21.00 UTC

FLIGHT REPORT:
Flew first flight leg at 20kft with T-39 on our tail. Did legs at 20. 25, and 31kft. Haze layer apparent at about 31kft. Sampled T-39 exhaust in racetrack pattern. pattern. First couple of legs were at 4-6 mi. and not very well coordinated (lots of manuevers). Got very close in subsequent legs. NO and DACOM indicated exhaust crossings periodically. NO got much larger plume concentrations than seen in DC-8 circle maneuvers. We couldn't align with the wind due to an instrument problem on the T-39. We were about 10-15 deg. off the wind.
After T-39 headed home, we flew for about 15 min. at 37kft to get a stratospheric sample. Then we descended to 29kft and sampled cirrus. Lidar had had a computer failure just before we entered the cirrus. Ice crystals were relatively large (< 200 microns). At around -40C Water clouds were apparent. After these legs, we headed home.

METEOROLOGY-REPORT
FORECAST: Warm tropopause, small chance of cirrus over CART site. Wind direction forcast to be 260 deg.
OBSERVATIONS: Lots of haze below about 30kft. Cirrus off to west with tops at about 25kft (consistent with GOES water vapor images, and west coast sounding indicating moisture at 400 mb). Low tropopause, warm upper trop., no conning during entire flight.

INSTRUMENTS: Forecast: All instruments are functioning. Lawson probe not on board.

  • BALLENTHIN: Operational, but still having problems with too much hydration
  • BAUMGARDNER: No problems
  • BRUNE: Sensitivity improved, still some problems
  • CHAN: Worked OK, may have heater problem
  • COGGIOLA: No problems
  • COOPER: Worked OK, but still couldn't operate below -20 C
  • DADS: Worked OK, hygrometers were giving invalid numbers
  • FERRY: Instrument worked well, but need to be warned about turns
  • GARY: No problems
  • GERBER: Operated well
  • HAGEN: Performed OK, one CN counter is down
  • HALLET: No problems
  • HEYMSFIELD: Worked well
  • HUDSON: No problems
  • LAWSON: Not on flight
  • RODGERS: No problems
  • SACHSE: No problems
  • TALBOT: No problems
  • TWOHY: No problems
  • UTHE: OK. only on minor computer glich during rapid altitude change.
  • VALERO: Only problem was one channel of TDDR failed late in flight
  • WEINHEIMER: No problems

Mission Highlights

  • T-39 exhaust aerosols were almost entirely nonvolatile. CCN in T-39 exhaust were enhanced by a factor of 2 or 3 over background values.
  • T-39 exhaust was easily detected by the chemistry package (high concentrations of NO and CO2 levels reached 360ppm)
  • Background aerosols on this flight were 90% volatile (an unusually large fraction).
  • A weak tropopause fold was detected near the jet in the southern region of the flight (180ppb ozone at 35000ft).
  • Even at the tops of the cirrus at 29000ft the ice crystals were very large (< 100 microns on the cloudscope and upward of 2mm on the replicator)

Mission Objective

T-39 Flight 04

  • To conduct near field sampling of the DC-8 exhaust plume.
  • To provide emissions for the DC-8 to sample.

Flight Log

TAKEOFF/LANDING:
The T-39 separted SLN at 1705UTC and returned at 1953UTC

FLIGHT REPORT:
The T-39 accomplished a rendezvous with the DC-8 at 5kft approximately 3min. after takeoff. The aircraft then ascended together to 30kft, with the T-39 sampling the emissions of the DC-8 20 to 100 meters downstream. After the aircraft reached the CART site, the T-39 took the lead position to allow the DC-8 to obtain in situ measurements of its emissions.

METEOROLOGY-REPORT:

INSTRUMENT STATUS:

  • CIMS - Not yet operational
  • MS - Met/Nav system - WORKED
  • AMS - Air Motion Sensor - WORKED
  • NDIR - CO2 - WORKED
  • 3760 - fine CN - WORKED
  • 3025 - ultra fine CN - WORKED
  • FSSP - 0.3-20um aerosols - WORKED
  • PCASP - 0.1-3um aerosols - WORKED

Highlights

  • The T-39 was able to fly at a fixed position only 20-50 meters behind the DC-8 and sample the exhaust of the individual inboard engines.
  • Large concentrations of volatile ultrafine particles were observed in plumes < 0.5 second old.

96/04/18 CART site activity

Meteorology at the Central Facility

Weather Conditions from Site Operators Log

Visiting Instruments at Central Facilities

 

CART Instrument Operations at Central Facilities

Key: O = operational, X = down or degraded

  • RASS, 50 MHz, (hourly): X
  • RASS, 915 MHz, (hourly): O
  • BSRN: O
  • SIROS: O
  • SMOS, (24 hrs): O
  • SWATS (24 hrs): O
  • EBBR, (24 hrs): O
  • WSI, (every 10 min.) X
  • MWR, (24 hrs): O
  • IRT: X
  • MPL, (24 hrs): X
  • BLC, (24 hrs): O
  • AERI, (24 hrs): O
  • SORTI, (daytime, sunny): O
  • Raman Lidar (daytime): X
  • 60M Temperature and Humidity: O
  • 25M Temperature and Humidity: O
  • 25M IRT: X
  • 25M MultiFilter Radiometer: X
  • 25M Upwelling IR: X
  • 25M Upwelling Solar: X
  • 10M IRT: O
  • 10M MultiFilter Radiometer: O
  • Aerosol System: X
  • Radiosondes, (Every 3 hrs, from 1:30 UTC): O

CART Instrument Operations at Boundary Facilities

There are four staffed Boundary Facilities, each having Balloon Borne Sounding Systems (BBSS) and MicroWave Radiometers (MWR). During the IOP period, sondes are launched every three hours round the clock, starting at 5:30 GMT (12:30 CST). The sites are listed below. Times listed following a site indicate questionable data or failed sonde launches. Weather conditions are recorded in the Boundary Facilities Site Operator's Log.

  • Hillsboro, KS (BF-1): Okay
  • Vici, OK (BF-4): Okay
  • Morris, OK (BF-5): Okay
  • Purcell, OK (BF-6): Okay

CART Instrumentation at Extended Facilities

There are numerous unstaffed Extended Facilities. The specific instrumentation at the extended facilities varies from site to site, but generally includes a flux station (either an Energy Balance Bowen Ration (EBBR) system or an Eddy Correlation (ECOR) system), a Solar and InfraRed Observing System (SIROS), and a Standard Meteorology Observing Station (SMOS). For the locations of the Extended Facilities, and their suite of instrumentation, see the table and map of the Extended CART site. The comments below indicate specific data streams with identified problems.

  • Problem at Extended Facility:
  • E1: SMOS, SIROS, ECOR
  • E3: SMOS, SIROS
  • E4: EBBR, SIROS
  • E7: SIROS
  • E10: SIROS
  • E16: ECOR

Key Comments/Observations related to flights

No persistent contrails. While not optimal for SUCCESS, these conditions were optimal for ARM UAV satellite calibration missions and for Bi- Directional Reflectance Function (BDRF) measurements.