SUCCESS 04/21/96 Mission Daily Schedule

The DC-8 and ER-2 flew a coordinated mission over the CART site to measure radiation and to profile optically thick cirrus, and over Texas to measure convective cloud inflow and outflow. For the radiation part, both the ER-2 and DC-8 flew up and down wind legs over the CART site ending with the DC-8 near the cirrus base in position to ascend in altitude for cirrus profiling. Although, the DC-8 made numerous passes through its own contrails it was unable to remain in any of them due to the low visibility provided by the cirrus. The ER-2 reported seeing many contrails including those of the DC-8. Flying south to Texas, the DC-8 flew around an isolated convective cell to compare the chemistry and aerosols of the convective inflow and outflow, at high altitudes, to that in the boundary layer. The ER-2 reported turbulence over the convective cloud tops.

Highlights

Flight Reports

ER-2 Flight: 96106

Date: April 21, 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 Summary

Take-off time was 1655 UTC and landing 2350 UTC. ER-2 flew 240 and 60 degree oriented lines (approximately 110 n mi long) over the ARM CART site (36 36.3'N 97 29.1'W) in coordination with the DC-8. ER-2 was at the CART site at 1815 UTC and the cirrus was moderate. On the 1823 to 1840 UTC the cirrus had thickened (could barely see the ground) and was extensive. During the later part of the cooridnated flight with the DC-8 the clouds over the ARM site began to break-up. DC-8 made vertical profiles of the clouds.

ER-2 ended coordinated pattern with the DC-8 at 2138 to overfly convection in vicinity of the ARM site. Convective overflights were of mature storms except the last leg when he flew over a storm that was just beginning to have cirrus blow-off. Location and times of thunderstorm runs were 36:09N 97:46W (2138 UTC) to 38:00N 94:19W (2207 UTC); 38:0N 94:10W (2213 UTC) to 37:55 N 90:45 (2225 UTC) to 36:42N 96:13W (2237 UTC) to 36:00N 97:27W (2248 UTC) to 35:48N 98:17W (2253 UTC) to 37:37N 97:00W.

Highlights

Lots of cirrus and contrails (including that of the DC-8) reported by ground observes at the ARM CART site. Overflew extended contrail toward end of coordinated runs with the DC-8. Overflew cold convective tops with the HIS and MIR. Many passes over the ARM CART.

CLS observed a pileus cloud during ER-2 runs over convection.

Instrument Status

  • MODIS Airborne Simulator (MAS): Operated. Good data collected on first tape. At 2124 MAS stopped recording data on second tape.
  • Cloud Aerosol Lidar System (CALS): Operated. Good data collected on first tape, problems recording on 2nd tape.
  • High-Resolution Interferometer Sounder (HIS): Operated. Good data collected.
  • Millimeter-wave Imaging Radiometer(MIR): Operated. Good data collected.
  • Tilt Scan CCD Camera (TSCC): Operated. Camera shutter problems.
  • Radiation Measuring System (RAMS): Operated. Good data collected.
  • RC-10 Camera: Operated (black and white visible film- 6 inch lens) ran out of film at 2118.

Additional Pilot Notes: ER-2 made a contrail on ascent.Commercial aircraft contrail at 1812 UTC. During legs between 2045-2103 and 2109-2129 the ER-2 flew over the DC-8 traveling in the opposite direction. Followed a long contrail (50-100 n. mi) during the 2109-2129 UTC leg. Circle rings of DC-8 spiral run near the end of the coordinated segment were visible from the ER-2. While over mature storms did have an "elevator ride" but not too much deviation in altitude. Reports of thunderstorm tops near 57K feet were consistent with pilot's observations. Growing cell had about 45 K feet.

 

 

Mission Summary

DC-8 SUCCESS flight #207 [960221] (scientists:Brian Toon, Danielle Jacob)

Objective: Our first objective is to profile a multilayer cloud structure over the CART site to provide ground truth for the radar. Our second objective is to make persistent contrails with the DC-8 for the ER-2 to observe and for us to sample. Our third objective is to sample the outflow of air from a convective cloud and compare that with boundary layer air so that we can see how aerosols in the upper troposphere, processed by cloud, compare with those in the boundary layer.

Instruments: All of the instruments are functional.

Meteorology expected: We expect high, middle and low clouds over the CART site. We also expect a line of convection near the Texas, Oklahoma border with isolated cells possible near us.

Flight plan: The plan is to pick a point about 15 min. upwind of the CART site and to fly constant altitude legs between that point and the CART site. First we will fly a leg near 20kft below cloud deck for the radiation instruments. Then we will fly a leg near 25kft for maximum radar return. Then we will fly a leg near 30kft at cloud top. Then we will fly multiple legs near the trop to make contrails. Over the CART site we will fly 3 360 degree turns so that we can sample the contrail. At the downwind point we will turn and try to fly up the contrail. After about three hours we will look for an isolated thunderhead, and fly around it at the altitude of the anvil. Next we will circle about 20kft. Finally we will fly a leg in the boundary layer.

Report on meteorology observed: The meteorology was close to predicted. There were low level clouds below 10kft over the CART site. Then a middle level cirrus from about 18-30 kft. Next a thin cirrus near the trop at about 35 kft. There were clear gaps between the cloud layers. The middle level cirrus was fairly uniform. In the afternoon a line of convection developed near the CART site and eventually moved over the CART site. We did find an isolated developing cell with an anvil about 30 miles long. The cloud top was near 40kft and the anvil tip near 29kft

Report on flight plan as flown: We flew the fight as planned. We flew legs near 16, 24, and 31kft based on CART reports on cloud base, max. radar return and cloud top. Then we made contrails near 35 and 36kft. Although we did make many passes through our contrail we were not able to see it well enough to remain within it. We also did a flight around the cumulus. We circled the top which did not allow long enough to sample the outflow air with the slowest sensors. However, we did not detect much air flowing out. Evidently the cloud was still spreading. So we may not be able to sample the processed aerosol this way.

Report on instrument performance:

  • BALLENTHIN: Operational
  • BAUMGARDNER: worked fine.
  • BRUNE: Fine.
  • CHAN: Good performance
  • COGGIOLA: Good
  • COOPER: Worked fine. Still having problem with low temperatures.
  • DADS: fine
  • FERRY: Worked fine.
  • GARY: Instrument performed well.
  • GERBER: Looks great.
  • HAGEN: fine
  • HALLET: Fine.
  • HEYMSFIELD: Looked fine.
  • HUDSON: Worked fine.
  • LAWSON: Worked fine.
  • RODGERS: Everything okay. Possible minor air leak in CN and IN.
  • SACHSE: Worked fine.
  • TALBOT: Worked fine.
  • TWOHY: Performed well.
  • UTHE: Worked fine
  • VALERO:
  • WEINHEIMER: Worked great

 

96/04/21 CART site activity

 

Meteorology at the Central Facility

Weather Conditions from Site Operators Log
Extensive altocumulus mid-morning gave way to variable cirrus fibratus cloud conditions ranging from dense fallstreaks occasionally down to 5.5 km to thin (bluish) detached cirrostratus layer at 11.0 km. Low level convection with local rain developed rapidly mid-pm.

 

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
  • E12: SIROS
  • E16: ECOR
  •  

 

Key Comments/Observations related to flights

The upper cirrus layer at 11.0 km appeared to contain contrails: we reported this layer height to Salina to set up a contrail mission following cirrus profiling. (Only short contrail segments were noted from the DC-8 in the lower cirrus.) The initial DC-8 pass was directly over the CART site and flown accurately into the layer wind, such that the persisting contrail remained overhead as it advected and spread for several minutes. Persisting contrail loops were then made to the NW of the site, but these were poorly targeted and did not drift over the site. Local convection began at this point. Later on upon exiting the area, DC-8 contrails were noted again over the site and to the NW, but developing showers and poor targeting prevented ground-based sampling.> At end of DC-8 mission, a long contrail was laid down into the wind but this was blocked from ground-based remote cloud sensing (gbrcs) by developing low clouds.