MODIS Airborne Simulator (MAS)

Objective and Summary:

• Overfly the ARM site in coordination with University of Washington CV-580 aircraft for remote sensing validation and cloud masking.
• Continue Northward without the CV-580 to fly several legs over the SHEBA ice camp (76°48'N, 167°31'W).

Coordinations:

• University of Washington CV-580 aircraft
• NOAA-14 satellite (2242 UTC)
• F-14 satellite (2341 UTC)

Key Flight Legs:

• The ER-2 flew three flight legs of about 260km in length, oriented with the solar azimuth (about 164° at mean time of overpasses), while the CV-580 attempted above and below-cloud bidirectional reflectance measurements and in situ profiles through the cloud.
• After overflying the ARM site, the ER-2 flew a NW flight line coordinated with NOAA-14 (318° heading). Because of a slightly earlier than scheduled takeoff, the pilot had to make two circular turns en route to the start of the SHEBA legs to match the timing of the satellite overpass.
• At the SHEBA ice station, the ER-2 made two-and-one-half North-South legs of about 260km in length. Because of a late turn-on for AirMISR during the Southbound leg over the ice station (point 6 to point 4), the pilot turned back to repeat the start of the leg (at point 6).
• The AirMISR was turned on for 6 acquisitions: three times over the ARM site, twice over SHEBA ice station, and once on the return over the ARM site. The AirMISR operated at the following times with notes of observed clouds as seen by the instrument:
  • 2043-2055 UTC (ARM - first 5 of 9 angles gathered; broken clouds)
  • 2111-2123 UTC (ARM - complete run of 9 angles; broken clouds)
  • 2139-2151 UTC (ARM - complete run; broken clouds)
  • 2249-2301 UTC (SHEBA - complete run; overcast with thin cloud)
  • 2332-2344 UTC (SHEBA - complete run; overcast with thin cloud)
  • 0101-0113 UTC (ARM - complete run; clear)

Pilot Report:

• reported cloud cover just North of Barrow during the flight legs over the ARM site, with clear sky to the South. Some cirrus was seen en route to SHEBA. The ice station was at the Northern end of an extensive solid cloud sheet with clear sky just to the North. Barrow was clear on the return leg.

Meteorology:

• Multilevel clouds, including cirrus, were expected throughout the region.
• SHEBA: Morning report of fog and clouds at all levels, including cirrus. Morning radar reported clouds from 3.1-3.8km; surface winds Southeasterly at 5kts. Near the time of the ER-2 overpass (2100 UTC) the ice station radar reported multiple cloud layers between 0.3-1.5km and 1.5-3.7km; lidar reported liquid stratocumulus at 3.5km; surface observations were clear to the NE, solid cover to the South, clearer to the West, surface winds from the Northeast at 5kts.

Instrument Status:

• AirMISR (Airborne Multi-angle Imaging Spectroradiometer): Partial first run, last five runs worked well
• AMPR (Advanced Microwave Precipitation Radiometer): Worked well
• CLS (Cloud Lidar System): Worked well
• HIS (High-resolution Interferometer Sounder): Worked well (had correctable time clock offset)
• MAS (MODIS Airborne Simulator): Worked well
• MIR (Millimeter-wave Imaging Radiometer): Worked well
• SSFR (Solar Spectral Flux Radiometer): Worked well