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FIRE-ACE ER-2 FLIGHT LOG |
| Author (Mission Scientist): Platnick, Steve Date: 1998060615 Submitted at: Sun Jun 6 19:07:09 UT 1998 |
Mission 11 ER-2 Sortie 98-076 Saturday, June 6, 1998 Steve Platnick: Flight Scientist |
Objectives: Overfly several flight legs over the NSA ARM site where relatively uniform stratus clouds are expected. Flight pattern coordinated with the University of Washington CV-580 aircraft for cloud remote sensing and cloud masking validation, cloud bidirectional reflectance measurements, and sea ice retrievals.
NOTE: The cloud lidar is down for the remainder of the mission making flights over multilevel clouds and cirrus more difficult for other ER-2 instruments to analyze. Therefore, the present flight, as well as tomorrow's remaining potential flight (Sunday 6 June 1998), will be planned for areas with well defined cloud layers or clear sky.
Coordinations included:
The ER-2 flew a NW flight line toward the ARM site to begin a cross pattern with legs of about 280 km in length. One-and-a-half flight legs were flown in a NW-SE orientation such that the imaging instruments scanned perpendicular to the solar azimuth, followed by a total of two flight legs in a direction chosen such that imaging instruments scanned into the solar plane.
The CV-580 flew above the ARM site in coordination with the ER-2, making above and below-cloud bidirectional reflectance measurements and in situ profiles through the cloud. The CV-580 reported a stratocumulus deck with a top at about 2500 ft. and about 1000 ft. thick, with a little stratus below. They reported clear skies above the stratocumulus deck during ER-2 overpasses.
The AirMISR was turned on for 5 acquisitions: twice over the Brooks range enroute to and from Barrow, and three times over the ARM site. The AirMISR operated at the following times with notes of observed clouds as seen by the instrument:
Pilot report: The ER-2 pilot reported solid low-level stratus deck over the entire flight operations area.
At 1500 UTC, the ice station reported stratus overcast clouds with surface winds at 4 kts, 310° and a ceilometer cloud base of about 0.5 km. Radar showing two cloud layers: lower one at 0.2-0.8 km and a higher layer at 3.9-4.5 km. The 1113 UTC sounding showed moisture increasing in a broad layer centered about 9 km. Satellite imagery showed broken high-to-midlevel clouds moving in from the northwest. Cloud cover at all levels expected to be over the ship by the time of an ER-2 flight.
The Barrow sounding showed two cloud layers, the upper one with cloud tops at about 3-3.5 km. Imagery was showing a rather uniform stratus deck across the Barrow region with a possible breaking up of the upper level cloud layer.
Due to lack of a working lidar on the ER-2, it was decided to focus a mission on Barrow where cloud layers were likely to be the most spatially uniform.
