The DC-8 and T-39 flew a coordinated mission over the CART site to profile stratus clouds and aerosols, and to provide data (FSSP) which will be useful for CART site radar systems calibration. The T-39 sampled the DC-8 exhaust at various altitudes, penetrating the stratosphere.
Flight Reports
Mission Summary
DC-8 SUCCESS flight #210 [960210] (scientists: Brian Toon and Eric Jensen)
SUMMARY: The basic flight went very well. Today's flight should provide a good dataset for calibration of the radar at the CART site. We also profiled the aerosols and our (DC-8) exhaust was sampled by the T-39 in the stratosphere.
Mission Objective
DC-8 TEST-FLIGHT
- profile a stratus cloud in the boundary layer over the CART site to help in calibration of the radar, and interpretation of ER-2 spectra
- profile the aerosols in the troposphere and lower stratosphere
- study the DC-8 exhaust with the T-39
Flight Track
Flight Log
OPERATIONS
FLIGHT PLAN:
Take off is planned for 1600 UT, 1100 am LT. We will proceed to the CART site and make two low level 15 minutes runs in the boundary layer near 3000 ft, centered on the CART site, along the wind. Then we will make 15 minute runs over the CART site at 10, 15, 20, 25, 30, 35, 37, and 41 K'. The T-39 will join us at 20 K'.
TAKEOFF/LANDING
The DC-8 left Salina at 16.03 UTC (11.03 am local time) and returned to Salina at 20.40 UTC
FLIGHT REPORT
Two legs were flown in the boundary layer stratocumulous over the CART site. The altitude varied from about 3500 to 5500 feet on these legs, as we attempted to stay in the clouds. The first leg was about 25 min. long, and the second leg was shortened to 15 min. (just past the CART site). We then flew 15 min. legs at 10, 15, 20, 25, 31, and 41 K'. The tropopause appeared to be very low (about 25 K'), but the temperature structure was very complicated. At the end of the 41 K' leg, three Lagrangian circles were flown, dropping about 80' per circle. CN and gas concentration measurements indicated several plume crossings.
METEOROLOGY-REPORT
FORECAST: We expect that a stratocumulus deck (possibly broken) will be present in boundary layer, and that it will be clear above. We expect the tropopause near 35 kft. Winds are forecast at 20-50 knots, 350 deg.
OBSERVATIONS: Stratocumulous was present over the CART site. The clouds were broken most of the time, and one relatively strong cell was penetrated on the second leg. Above the stratus, a few wispy cirrus were present at 15-20 K'. No contrails were observed all day.
INSTRUMENT STATUS
All instruments are functioning.
- BALLENTHIN: No problems
- BAUMGARDNER: No problems
- BRUNE: No problems, except for missing NO.
- CHAN: No problems
- COGGIOLA: Possible failure of main data aquisition board.
- COOPER: CCN/IN instrument failed.
- DADS: Minor problems with 2-stage hygrometer early in flight.
- FERRY: No problems
- GARY: No problems
- GERBER: No problems
- HAGEN: No problems
- HALLET: No problems
- HEYMSFIELD: No problems
- HUDSON: No problems
- LAWSON: Failure due to cable problem.
- RODGERS: No problems with CN. IN appeared to have a leak.
- SACHSE: No problems
- TALBOT: No problems
- TWOHY: No problems
- UTHE: Had one temporary computer failure
- VALERO: No problems
- WEINHEIMER: No problems
Mission Highlights
- FSSP measurements in the stratus clouds should provide a good dataset for calibration of the radar at the CART site - most particles were smaller than 20 microns
- substantial amounts of particulate NOy were observed in the stratocumulus with a peak near the cloud tops
- a complicated tropopause structure was observed
- the DC-8 exhaust plume was sampled in the clean stratospheric environment
Mission Objective
T-39 Flight 10
- To conduct sampling of the DC-8 emissions at a variety of atmospheric conditions.
Flight Log
TAKEOFF/LANDING:
The T-39 departed SLN at 1727UTC and returned at 2000UTC
FLIGHT REPORT:
The T-39 accomplished a rendezvous with the DC-8 over the CART site at 20kft. The T-39 flew a racetrack course up and down wind with the DC-8 leading at altitudes of 20, 25, 31 and 41 kft.
METEOROLOGY-REPORT:
INSTRUMENT STATUS:
- CIMS - mass spec - WORKED
- MS - Met/Nav system - WORKED (No GPS)
- AMS - Air Motion Sensor - WORKED
- NDIR - CO2 - WORKED
- 3760 - fine CN - WORKED
- 3025 - ultra fine CN - WORKED
- FSSP - 0.3-20um aerosols - Software problem
- PCASP - 0.1-3um aerosols - WORKED
Highlights
- performed several plume crossings at aircraft separations varying from 0.05 to 4 km.
- Recorded outstanding video of DC-8 and T-39 flight dynamics in wake crossings.
96/04/29 CART site activity
Meteorology at the Central Facility
Weather Conditions from Site Operators Log
Low stratus and some scattered cumulus predominated. Some virga present, light mist or rain was felt around 20:00. Moderate winds of 15-20 mph were from the north and northwest. A light haze persisted throughout the day.
Visiting Instruments at Central Facilities
Active Measurement Instruments
- ETL - CO2 doppler lidar: 14:00-21:00
- UoU - Polarization Diversity Lidar (PDL): 16:00-18:00
- UoU - 95 GHz scanning cloud radar: X
- PSU - 94 GHz vertical cloud radar: 13:00-20:00
- UMa - 95 GHz scanning cloud radar: 14:00-22:00
Passive Measurement Instruments
- SCR - solar radiometers: 15:00-20:00
- ARC - SPectral Flux Radiometer (SPFR): 15:00-21:00
- ARC - Digital Array Scanning Interferometer (DASI): X
- ASD - FieldSpec FR full range radiometer: X
- DeU - Absolute Solar Trans. Interferometer: X
- CSI - IR Radiometer: X
- UoU - IR Radiometer in PDL trailer: 16:00-18:00
- GSF - triple MWR system: All day
- PNL - wide-view camera and time-lapse VCR: X
- UoU wide-view video camera: 16:00-18:00
- BNL - CSPOT, Cimel Sun/sky PhOTometer: All day
CART Instrument Operations at Central Facilities
Key: O = operational, X = down or degraded
- RASS, 50 MHz, (hourly): O
- 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.) O
- MWR, (24 hrs): O
- IRT: X
- MPL, (24 hrs): O
- 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: O
- 25M MultiFilter Radiometer: O
- 25M Upwelling IR: O
- 25M Upwelling Solar: O
- 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: ECOR
- E2: SIROS
- E3: SIROS
- E4: SIROS
- E6: SIROS
- E7: SIROS
- E10: SIROS
- E16: ECOR
- E20: SMOS, EBBR, SIROS
- E24: SIROS
Key Comments/Observations related to flights
Two low altitude passes were made by the DC-8 through the early stratus clouds. The MPL reported these stratus between 1-2 km. Later higher altitude flights with the DC-8 and T-39 were difficult to observe from the ground due to low clouds.