SUCCESS 04/20/96 Mission Daily Schedule

The DC-8 and ER-2 flew a coordinated cirrus cloud profiling mission over the CART site, where only patchy, optically thin cirrus (and halos) were observed during the entire day. Both ER-2 and DC-8 flew up/down-wind legs over the CART site. Only the first leg was coordinated for a radiation measurement time-series, with the DC-8 below the cirrus deck. For the cirrus profiling the DC-8 ascended in an up/down-wind flight-leg racetrack pattern and descended in slow spirals near the CART-site. The ER-2 observed lots of cirrus and contrails over the CART site. One of the contrails extended over 37km. The DC-8 observed cirrus over CART site. Ground observations indicated that the DC-8 made persistent contrails in temperatures as high as -38C in patchy cirrus. The T39 flew a test flight to test the chemical ionization mass spectrometer system.

Highlights

Flight Reports

ER-2 Flight: 96105

Date: April 20, 1996

Mission: Cirrus and persistent contrails over ARM CART site.

Mission Objectives

Observe cirrus clouds of various ages and contrails in the presence of cirrus. In situ cloud sampling with the DC-8 with ground-based uplooking and ER-2 based downlooking characterization of cirrus and contrails. Investigate differences in the radiative signature of contrails and natural cirrus. Flight plans support combined ER-2 remote sensing and DC-8 in situ cloud microphysics studies.

Flight Track

Flight Summary

ER-2 ENE-WSW oriented lines over the ARM CART site. First two legs are approximately 115 nm long with the ARM CART (36 36.3'N 97 29.1'W) site near the WSW end of the leg. This first leg was coordinated with the DC-8 starting at 37 32.6 N 95 23.7W (060 at 115 from ARM site) with the second point at the ARM site. After two legs the ER-2 heading was adjusted to approximately 80 and 100 degrees with straight line patterns centered on the ARM site. Flight path of the ER-2 was again adjusted around 1925 (during the ninth horizontal flight leg) to align with the DC-8 (headings of approximately 60 and 240 degrees).

Cirrus in westerly flow aloft of varying thickness over ARM CART site and along ER-2 flight line. DC-8 made vertical profiles of the clouds.

Highlights

Lots of cirrus and contrails reported by the ARM CART site during this mission. Twelve overpasses of ARM CART site (approximately 1604, 1618, 1657, 1721, 1745, 1808, 1833, 1856, 1921, 1945, 2009 and 2033 UTC).

At approximately 1556 UTC the MAS observed a large contrail extending across the entire swath (37 km).

Instrument Status

  • MODIS Airborne Simulator (MAS): Operated. Good data collected. Stopped recording at 1942.
  • 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. Good data collected, data disk filled before end of flight.
  • Radiation Measuring System (RAMS): Operated. Good data collected.
  • RC-10 Camera: Operated (black and white visible film- 6 inch lens).

Additional Pilot Notes:. During first two legs that were coordinated with the DC-8, conditions were mostly clear--the DC-8 was making broken contrails that were visible from the ER-2. At the end of flight ARM site was mostly overcast, though breaks in the cloud did exist. Contrails were visible during mission. Circle rings of DC-8 spiral run near the end of the mission were visible from the ER-2.

 

DC-8 Mission Summary

The basic flight went very well. All of the instruments are functioning, with mainly small problems left to be worked out. After, the two initial (with the ER-2 coordinated) radiation flight legs, with the DC-8 below the cirrus cloud deck, the DC-8 twice profiled the cirrus - stepwise ascending via horizontal up-/down wind flightlegs with CART-site overpasses and descending in Lagrangian loops near the CART-site. As there were no mid-level and low-level clouds this flight promises to be a great case (1) for the validation of microphysical properties predicted by from remote sensing measurements and (2) for an improved understanding between cirrus microphysic and radiative transfer. The DC-8 layed contrails above 27000ft and temperatures as high as -38 C. These contrails were frequently persistent in or near areas of patchy cirrus. We had a difficult time to find our own contrail during loops or during return legs as the contrail remnants were frequently obscured by older cirrus.
DC-8 SUCCESS flight #206 [960206] (scientists: Brian Toon and Eric Jensen)

 

Mission Objective

The objective of this flight is to thoroughly investigate a cirrus cloud system over the CART site. Ice crystals in the cirrus will be sampled at several levels. Coordinated legs with the ER-2 above the DC-8 will be used to study the radiative properties of the cirrus. In addition, we will evaluate the impact of the DC-8 exhaust/contrails on the cirrus.

 

Flight Track

Flight Log

FLIGHT PLAN:
For the duration of the flight, 100 mi. legs will be flown along the wind (predicted to be 240 deg.) over the CART site. The upwind end of the legs will be at the CART site. The ER-2 will rendezvous with the DC-8 at the downwind waypoint, and the first two legs will be flown with the two planes stacked. Subsequently, the ER-2 will be flying uncoordinated 130 mile legs over the DC-8 flight track.
The first two DC-8 flight legs will be at cloud-base (predicted to be 20 K'). Then we will step up in altitude to cloud top (nominally in 2 K' increments assuming a cloud-top at 30 K'). The top leg should be just above cloud top to see if persistent contrails form there. Next, we will spiral down over the CART site and repeat the pattern. During the second pattern, we may fly each leg twice to see whether we are laying a persistent contrail in the cloud or otherwise altering the cirrus.
At the end of this pattern, if time permits, we will fly two 15 minute legs in the stratosphere.
At some point, we will do a box pattern for MMS calibration.

TAKEOFF/LANDING
The DC-8 left Salina at 15.23 UTC (10.23 am local time) and returned to Salina around 21.30 UTC

FLIGHT REPORT: For the first stairstep pattern, legs were flown at 20, 24, 26, 29, and 32 K'. On the leg at 32 K', we suspected that we were laying a persistent contrail, so we flew back on the same leg. The contrail was persistent and clearly visible from the cockpit, but we missed it in the turn.
For the second leg, time ran short, so we did legs at 22, 27, and 33 K'. The leg at 33 K' was repeated to attempt to find contrail. No contrail was visible from the cockpit, but we were near the tops of the clouds, so it was difficult to detect.
At the end of the last 33 K' leg, we circled a few times, sampling our contrail a few times. Then we spiraled down to 23 K' and headed home.
METEOROLOGY-REPORT
FORECAST: Meteorology expected: Cirrus are expected throughout the flight over the CART site with tops ranging from 30-35 K'. The upper troposphere should be cold enough to form contrails.
OBSERVATIONS: Cirrus over the CART site thickened throughout the day over the CART site. Early in the flight, cirrus were only present at the west end of our leg. Later in the flight cirrus were present on nearly the entire leg from about 24 - 33 K'.

INSTRUMENTS: Forecast: All instruments are functioning except: CIMS (Ballenthin, Viggiano, & Miller) will not be operated.

  • BALLENTHIN: Not on plane
  • BAUMGARDNER: Worked well
  • BRUNE: Heaters improved the laser stability. HO2 still not working
  • CHAN: No problems
  • COGGIOLA: Instrument worked, but sensitivity was low. Need parts
  • COOPER: O.K. Still had low T problems
  • DADS: O.K. Some hygrometer problems
  • FERRY: Worked well
  • GARY: Worked fine
  • GERBER: Worked well
  • HAGEN: Worked well
  • HALLET: Worked O.K.
  • HEYMSFIELD: No problems
  • HUDSON: Worked well
  • LAWSON: Worked well most of flight. Had problems later
  • RODGERS: Worked well. IN down to -33 C
  • SACHSE: Worked well
  • TALBOT: OK
  • TWOHY: Worked fine
  • UTHE: O.K. Still having computer gliches
  • VALERO: Everything worked
  • WEINHEIMER: Worked fine

 

Mission Highlights

 

  • Cirrus observed over CART site should provide good case study for cirrus radiative properties and remote sensing validation.
  • Reports from ground observers indicate that we were making persistent contrails at temperatures as high as -38 C in patchy cirrus.

 

Mission Objective

T-39 Flight 05

  • To check the newly installed chemical ionization mass spect system.

 

Flight Log

TAKEOFF/LANDING:
The T-39 departed SLN at 1800UTC and returned at 2000UTC

FLIGHT REPORT:
The T-39 flew to 41kft to observe the performance characterstics of the CIMS instruments.

METEOROLOGY-REPORT:

INSTRUMENT STATUS:

  • CIMS - mass spec - WORKED
  • 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 - Software probelem
  • PCASP - 0.1-3um aerosols - WORKED

 

Highlights

 

  • The T-39 was able to perform needed instrument checks.

96/04/21 CART site activity

 

Meteorology at the Central Facility

Weather Conditions from Site Operators Log
Variable mostly thin cirrostratus and fibratus, in several layers between 6.6 to 11.0 km, nice 22 degree halo at times

 

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): O
  • BLC, (24 hrs): O
  • AERI, (24 hrs): O
  • SORTI, (daytime, sunny): O
  • Raman Lidar (daytime): O
  • 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
  • E3: SIROS
  • E10: SIROS
  • E11: SIROS
  • E16: ECOR
  •  

 

Key Comments/Observations related to flights

Several contrails from DC-8 and Egrett briefly sampled. Excellent day. High cirrus and abundant persistent contrails, especially embedded in established cirrus.

UAV flight with Egrett and Otter was well coordinated with this flight day.

CART-site observations (04/20):

warm day, calm surface winds
cirrus cloud during the entire day, no mid-level and low-level clouds
cirrus was patchy, especially in the morning, cirrus (cells) thickened during day and gave a less broken cloud appearance
lots of cloud structure visually - supported by lidar observations: many cloud layers, initially between 25000ft and 30000ft; later spreading to altitudes between 19000ft and 33000ft.
cirrus cloud-field moved in SW to NE direction over the site
22deg halos was observed almost during the entire day

observed DC-8 overpassed (generally approaching from the NE, turning just SW of the CART-site and disappearing towards the NE; times in UTC)
16.10 DC-8 turning underneath a halo and under the contrail of the ascending Egrett
16.58 DC-8 overhead and turning back
17.13 DC-8 contrail created during the turn passes over the CART-site lidar thickness about 300m
17.30 continued broken cirrus cloud field: temporary thickening of cirrus, loss of halo, vertical structure seen to the N
17.45 DC-8 passed to the S (no contrail at 27000ft)
17.50 DC-8 passed directly over CART-site, weak contrail only more persistent in cloudy areas
18.05 strong cell, almost loosing the sun-disk
18.18 direct sun-light yet clouds overhead: cloud-street type cirrus structure with cloud bands oriented in wind-direction (necessity for cross-wind profiling)
18.28 DC-8 passing over the site laying a long contrail and looping over the CART-site (first loop completed at 18.33, though drifting away to the north of the CART-sitei; second loop completed at 18.38 NE of CART site; visual contact lost after the 2.5 loops when DC-8 probably stopped making contrails)
xx.xx missed DC-8 overpass and loop
19.40 DC-8 passing overhead (laying a contrail that is persistent in the cloud)
19.45 DC-8 cossing its own contrail on the downwind (out) leg at 33000ft
20.21 DC-8 overhead and laying persistent contrails which created dark shadows on the lower cirrus cloud deck
20.22 DC-8 started loops north of the CART site (loop1: 20.27, loop2: 20.37, completed (making contrails), later visually lost - as Lagrangian Loops moved the aircraft away from the CART-site