MODIS Airborne Simulator (MAS)

Objective and Summary:

• Overfly surface sites at Barrow (71°19.37'N, 156°34.9'W) and the SHEBA ice station (76°18.7'N, 166°7.1'W), then to fly a repeated E-W and N-S cross pattern over SHEBA.
• The mission was coordinated with the C-130Q at 2300 (solar noon), with the ER-2 flying North over the SHEBA ice station while the C-130Q was within the mid-tropospheric cloud layer for 50km on a Southbound leg.

Coordinations:

• C-130Q aircraft (2300 UTC)
• F-14 satellite (2145 and 2326 UTC)
• NOAA-14 satellite (2207 UTC)
• Solar noon (2300 UTC)

Key Flight Legs:

• The ER-2 overflew the SHEBA ice station (point 1) during an E-W grid from point 2 (76°18.7'N, 167°45'W) to/from point 3 (76°10'N, 157°W) that consisted of 2 flight legs 284km in length, followed by a N-S grid from point 4 (74°18.7'N, 166°7.1'W) to/from point 5 (77°12.7'N, 166°7.1'W) that consisted of 2.4 flight legs 285km in length. These flight tracks passed over the SHEBA ice station at 2137, 2222, 2234.5, 2259, and 2322 UTC.
• The AirMISR was turned on for 5 acquisitions: twice over the Barrow ARM site (enroute and return) and 3 acquisitions over the SHEBA ice station. The AirMISR operated at the following times with notes of observed clouds as seen by the instrument:
  • 2042.5-2057 UTC (ARM)
  • 2216.5-2230 UTC (SHEBA)
  • 2253.5-2306.5 UTC (SHEBA)
  • 2316.25-2331.25 UTC (SHEBA)
  • 0009.75-0026 UTC (ARM)

Pilot Report:

• The ER-2 pilot reported 98% low cloud cover (undercast) starting approximately 200nm North of Fairbanks. Very few breaks in the clouds were observed.

Meteorology:

• A multilayer cloud system consisting of low stratus, mid-level altocumulus (3-4.5km) and upper level cirrus (7.25-8km) reported at the SHEBA ice station.
• A dry layer was seen in the sounding from the ice station between 900 - 650mb.
• The satellite imagery showed a low level cloud to the South of SHEBA and a multi-layer cloud at SHEBA at 1415 UTC, with temperature inversions at 0.5, 3.2, and 4.2km. Winds were from 65° (ENE) at a speed of 21kts.

Instrument Status:

• AirMISR (Airborne Multi-angle Imaging Spectroradiometer): No aft camera viewing (C and D camera positions) and log files not written
• AMPR (Advanced Microwave Precipitation Radiometer): Worked well
• CLS (Cloud Lidar System): Lidar worked properly, but navigation data not recorded
• HIS (High-resolution Interferometer Sounder): Worked from take-off to near SHEBA the first overpass (~1.5 hr) and then failed; cause not determined
• MAS (MODIS Airborne Simulator): Port 4 bands (8.3-14.0 µm) noisy and unsatisfactory; will be taken off MAS for next 5 days to purge with nitrogen evaporate ice
• MIR (Millimeter-wave Imaging Radiometer): Worked well
• SSFR (Solar Spectral Flux Radiometer): Worked well