SUCCESS 04/16/96 Mission Daily Schedule

The T-39, DC-8 and ER-2 flew a coordinated mission over the CART site, under patchy cirrus clouds. The T-39 created contrails (by flying circles) upwind of the CART site. At the same altitude, but downwind of the CART site, the DC-8 flew perpendicular to the wind-direction to sample the remnants of the T-39 contrails, which were not too persistent to be easily identified, and to profile the patchy cirrus cloud-field. The ER-2, while flying an wind pattern, observed the other aircraft from above them. After the T39 exhausted its fuel and returned to Salina, the DC-8 continued to fly under, and with the same pattern as the ER-2. At 2006 UTC measurements were coordinated with the NOAA-14 satellite overpass.

Highlights

Flight Reports

ER-2 Flight: 96104

Date: April 16, 1996

Mission: Persistent contrails/cirrus over ARM CART Site.

Mission Objectives

Observe T-39 and DC-8 generated persistent contrails of various age. Contrail advection over CART site will be overflown by ER-2 for combined ground-based uplooking and ER-2 based downlooking characterization of contrails/cirrus. Characterize ambient radiometric conditions of atmosphere by flying upwind of T-39/DC-8 contrail generation region.

Flight Track

Flight Summary

ER-2 launch at 1700 UTC; ER-2 recovery at 2335 UTC. ER-2 flew 12 legs of an east-west oriented line (headings 90 and 270 degrees true north; 130 nm length) with ARM CART site (36 36.3'N 97 29.1'W) positioned 50 nm from western end of nadir flight line. Final 2 legs extended to 180nm for additional downwind coverage of old contrails. Total of 12 overpasses of ARM CART site. T-39 flying 10 nm diameter circles positioned 10, 20, and 30 nm upwind (west) of ARM CART site. DC-8 flying north-south oriented legs centered at 0, 10, 20, and 30 nm downwind of ARM CART site and then flying racetrack (oriented about 15 degrees off ER-2 heading). No time-dependent positioning coordination between ER-2 and DC-8 or T-39.

Cirrus in westerly flow aloft of varying thickness over ARM CART site and all along ER-2 flight line. T-39 contrails were not persistent. DC-8 contrails more persistent than T-39. ER-2 pilot had 2 visual observations of DC-8 contrail (1802 and 2009:30 UTC).

ARM CART site Central Facility coordinates verified for DC-8 and ER-2 flight plans.

Highlights

Lots of cirrus of varying thickness observed by ER-2. DC-8 with contrail apparent in MAS data at 1802 and 2009 UTC. ARM CART site uplooking lidar operatining during mission. Twelve overpasses of ARM CART site (approximately 1758, 1828, 1849, 1918, 1939, 2009, 2030, 2100, 2121, 2150, 2211, and 2154 UTC).

Instrument Status

  • Modis Airborne Simulator (MAS): Operated. Good data collected.
  • Cloud Aerosol Lidar System (CALS): Operated. Good data collected
  • High-Resolution Interferometer Sounder (HIS): Operated. Good data collected.
  • Millimeter-wave Imaging Radiometer(MIR): Operated. Good data collected.
  • Tilt Scan CCD Camera (TSCC): Operated in non-data collection mode.
  • Radiation Measuring System (RAMS): Operated. Good data collected.
  • RC-10 Camera: Operated on all but first flight leg (black and white visible film- 6 inch lens).

Additional Pilot Notes:. DC-8 contrail short-lived at 1802 UTC encounter. No visual of T-39 aircraft or contrails.

 

Mission Summary

DC-8 SUCCESS flight #204 [960204] (scientist: Eric Jensen)

SUMMARY: This flight turned out to primarily be a cirrus profiling mission. Reports from the ER-2 and the ground indicated that the T-39 did not generate persistent contrails. There were occasional indications of contrail crossings. It was a very successful cirrus sampling flight. Patchy cirrostratus were present most of the time during our crosswind pattern south of the CART site.

Mission Objective

DC-8 FLIGHT 204

  • get a complete picture of persistent contrail properties, evolution, and environmental conditions. Persistent contrails generated by the T-39 will be sampled in situ by the DC-8, and remotely from the ER-2 and from the ground as they advect over the CART site.
  • use the DC-8 to sample its own contrail and generate a contrail aligned with the wind upwind of the CART site.
  • profile the cirrus layer

Flight Track

 

Flight Log

OPERATIONS
FLIGHT PLAN:
Planned takeoff: 17.00 UTC (12.00 local time) for a six hour flight.
Part 1: The T-39 will first fly a set of 4 10-mile-diameter circles centered 10 mi. upwind of the CART site. Next, the T-39 will fly 4 10-mile-diameter circles centered 20 mi. upwind of the CART site. Finally, 4 more circles 30 mi. upwind of the CART site.
Assuming a 60 knot wind speed, it will take about 30 min. for the contrails to advect 30 mi. downwind of the CART site where the DC-8 will begin sampling them. During this time, the DC-8 should profile any cirrus in the area while staying at least 30 mi. downwind of the CART site. Once the T-39 contrails have advected 30 mi. downwind of the CART site, the DC-8 will fly 4 10-min. flight legs normal to the wind, crossing the T-39 contrails. Each flight leg will be 10 mi. closer to the CART site such that the 4th leg will go over the CART site. After the 4th leg, the DC-8 will fly downwind to 30 mi. downwind of CART site and again fly 10 min. legs normal to the wind. The first 3 legs should all be at 30 mi. downwind of CART site so that old DC-8 contrails can advect out of the way. The 4th, 5th, and 6th legs will then be at 20, 10, and 0 mi. downwind, respectively.
The ER-2 will fly tracks over the CART site, aligned with the wind for the duration of the mission. The track should extend 20 mi. upwind of T-39 circle and 60 mi. downwind of CART site (maximum 110 mi. flight track).
Part 2: After the T-39 heads home, the DC-8 will fly straight legs inclined 10-20 deg. to the wind. The legs will be about 20 min. long. The objective will be to fly back up the contrail from the previous leg. The upwind leg will cross several miles upwind of the CART site such that the contrail advects over the CART site before the DC-8 flies back up its contrail.About 4 legs will be flown. The ER-2 will continue flying upwind and downwind over the CART site extending just upwind and downwind of the DC-8 contrails.
After the last contrail-sampling leg, the DC-8 will fly directly upwind over the CART site and continue upwind 60 miles. The ER-2 will fly a few hundred mi. downwind from the CART site to image old contrails.

TAKEOFF/LANDING
The DC-8 left Salina at 17.05 UTC (12.05 am local time) and returned to Salina at 22.50 UTC

FLIGHT REPORT
The CART site relayed cirrus altitudes at 27000, 33000 and 35000ft.
The Sabre-liner left Salina at 17.00 UTC to make circle contrails about 10 miles upwind of the CART-site at 35000ft.
The DC-8 left Salina at 17.05 UTC. The DC-8 headed downwind of the CART-site for cross-wind cirrus profiling (up and dn 10 minute flight-legs) at first at 27000ft (2 legs), then at 31000ft (2 legs) and finally at 35000ft (4 legs) - at that altitude also to sample aged T-39 contrails.
At 27000ft 'tons of particles' were detected in patchy cirrus by the Lawson probe and by the 2DC-probe. On the second leg there was a short power failure. (Converter 1 died at 17.30 UTC and it took a few minutes to bring back up.)
At 31000ft cirrus streaks were seen above and below and in the vicinity, though it also appeared cloud-free locally. Persistent contrails were seen above.
At 35000ft the DC-8 layed a contrail (started to do so at 32000ft - 18.00 UTC, which was detected by the ER-2 pilot from above). Commercial aircraft crossed above and layed contrails, that lasted about 20 km, but they were not persistent. The DC-8 was skimming along the top of patchy cirrus, with nice fallstreaks to lower elevations.
Cirrus was observed at all three altitudes (no low and mid level clouds), fallstreaks were mainly below 30000ft. Cirrus was more frequent and optically thicker towards the northern sections of the north-south flight legs. Cirrus was patchy and often it appeared that the aircraft was flying in cloud-free air with cirrus all around. With increasing altitude there were less particle counts on the 2DC probe, though many small crystals (10um size and smaller) were detected by the replicator (Hallet) and by the VIPS (Heymsfield).
The CART site indicated that the DC-8 was generating a persistent contrail at about 18:25 UTC.
The temperature was about -62C. MTP reported that the tropopause was at about 39000ft most of the flight. For most of the pattern, the lidar was restricted to scanning below 0 degree.
On the fourth leg at 35000ft the DC-8 passed over the CART site. We noticed (possible T-39) contrail left-overs below us (18.50 UTC).
The ER-2 reports seeing T-39 and DC-8 contrails, however, these contrails are non-persistent. It was decided to climb to 37000ft. The T-39 (on request) climbed to 37000 ft, while the DC-8 made four more flight legs at 35000ft to catch remnants of T-39 contrails.
On these legs the DC-8 - at least once - crossed our own contrail: VIPS showed many sub-10um crystals and relative humidity is above 100% (to ice).
At 37000ft the DC-8 was still creating contrails, though not persistent. We passed several contrail remnants (T-39), though, there were difficult to identify visually, due to cirrus break-off and smoke from fires at the surface.
The T-39 returned, and as the DC-8 were unable to create persistent contrails it was decided to profile the cirrus/contrail cloud deck.
The DC-8 descended to 29000ft and flew east-west flight legs at over the CART site.
At 29000ft DC-8 did not produce any contrails. The CART site was obscured by a thicker cirrus patch.
At 32000ft, DC-8 started to produce a slight contrail, but lost that ability towards the end of the flight-leg (winds 70kn/ 266deg).
At 35000ft (above 33000ft) the DC-8 made contrails again. The DC-8 passed several aged contrails (slightly below) indicated also by chemistry measurements. The relative humidity (DADS) is shown to be consistently above 115%. The DC-8 altitude at 37000ft was cancelled and instead the DC-8 returned into its own contrail: great data! (NO, NOy, CN, VIPS). We measured in the DC-8 contrail for several miles. Early on, the contrail was embedded in the cirrus top, then in clear air. The aircraft was maneuvered such that both wingtips could sample the contrail.
Finally, the DC-8 climbed into the stratosphere (tropopause at 39000ft).
At 41000ft (-64C, 140% (?)) the DC-8 laid long (though not persistent) contrails. Contrails were clearly visible during a slow wide turn.
The DC-8 then descended (at 22.00) in an Eulerian spiral (not exceeding 1000ft descent per minute) over the CART site in optically thin cirrus, as the ground was visible during the spiral. Some wiggling MMS maneuvers were flown on the return to Salina. Landing (in strong southerly winds) occurred at 22.50 UTC.

METEOROLOGY REPORT
Forecast: Thin cirrus (possibly thick). High humidities in upper troposphere. Tropopause height of about 12 km.
Observations: As expected, tropopause was high and cold near 12 km and about -65 C. No mid-level or low-level clouds, though cirrus. Cirrus was freqently patchy and thickend up as the day progressed. Many contrails were oberserved though not always very persistent (passing planes). The DC-8 preduced contrail above 32000ft well into the stratosphere.

INSTRUMENT STATUS
The Gerber probe was not on the plane. The three stage hygrometer pump was broken and was replaced by a two stage pump. The Lawson probe was back on.

  • BALLENTHIN: worked well
  • BAUMGARDNER: worked well
  • BRUNE: ATHOS worked for about 2 hours before laser dye died
  • CHAN: worked well
  • COGGIOLA: worked well
  • COOPER: problems with CN counter, should be fixed by tomorrow
  • DADS: worked well except for 3 minutes down due to converter 1 power outage
  • FERRY: 2-D worked. MASP had problems. One impactor bent.
  • GARY: worked well. No problems
  • GERBER: not on plane. May be ready tomorrow
  • HAGEN: worked well.
  • HALLET: worked OK. Had problems at high altitudes. Replicator worked well
  • HEYMSFIELD: worked well
  • HUDSON: worked OK
  • LAWSON: probe is working but needs some tweaking
  • RODGERS: problems with IN instrument early in flight, corrected later.
  • SACHSE: everything worked well. Need to change reference CO2 instrument
  • TALBOT: no problems
  • TWOHY: got good data. Need to fix minor leak sometime.
  • UTHE: had several power failures. Scanning operation was limited by ATC
  • VALERO: OK. except for one dn-TDDR channel.
  • WEINHEIMER: worked well.

 

Mission Highlights

 

  • DC-8 measuring its own persistent contrail on a return leg at 35000 ft altitude near the CART site
  • detection of many small ice-crystals in upper tropospheric cirrus
  • occasional intersection with aged contrails
  • laying persistent contrails in the lower stratosphere (41000ft, -64C)

 

Mission Objective

T-39 Flight 03

  • Produce contrails for in situ sampling by the DC-8

 

Flight Log

TAKEOFF/LANDING:
The T-39 separted SLN at 16:59UTC and returned at 20:06UTC

FLIGHT REPORT:
The T-39 flew to a position 10mi. west of the CART site and executed a series of 10mi. diameter circles at 35, 37, and 39kft.

METEOROLOGY-REPORT:
Fairly dense cirrus at 29-30kft. Patchy cirrus at 32-36kft. Contrails were persistent only in regions of cirrus.

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

 

  • Accomplished low altitude rendezvous with the DC-8 and satisfactory formation flight.
  • Made several dozen crossings of the DC-8 plume at separations of 0.8 to 8 miles.
  • Observed large concentrations of volatile ultra fine particles at all distances behind the DC-8.

96/04/16 CART site activity

 

Meteorology at the Central Facility

Weather Conditions from Site Operators Log
Near overcast of variable thin (bluish-colored) fibratus, frequent contrail segments, cirrus tops up to 11.5 km MSL, bases down to 7.0 km. Mild winds of 8-15 mph from the west and northwest.

 

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.) O
  • 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: O
  • 25M Upwelling IR: O
  • 25M Upwelling Solar: O
  • 10M IRT: O
  • 10M MultiFilter Radiometer: O
  • Aerosol System: O
  • 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
  • E4, SIROS
  • E6, SMOS, SIROS
  • E10, SIROS
  • E11, SMOS, SIROS, ECOR
  • E16, ECOR
  •  

 

Key Comments/Observations related to flights

Upwind T-39 contrail loops tended to generate only incomplete contrail segments at the height of the existing cirrus, typically only in association with the patchy natural cirrus present. Moreover, although several were sampled from the ground, most of the contrail bits were poorly targeted by the T-39 and passed just to the S of the CART site.