1998-05-20 (Flight #1751)
Aircraft Flight Summary
Flight Track Map
Observed both the top and bottom of a stratus layer, using the CAR instrument to either scan upward through the zenith, or downward through the nadir while viewing the cloud. Also scanned the inside of the stratus layer within the diffusion domain with the CAR in the starboard viewing mode. Conducted BRDF measurements over pack ice with a few dispersed leads. (A lead is a small section of open ocean that occurs as the pack ice melts and breaks in the summer time.). Total of 22864 scan data was collected between 19:55:55 - 23:45:04 UTC.
During this flight, we encountered a nice thick stratus layer. The base of the cloud layer was located at 900 ft MSL and its top at 2402 ft MSL.
19:56: the filterwheel channel for the CAR for the entire flight was locked on 1.725 µm. Leaving Barrow, the CV-580 flew just under a stratus layer over a surface that was mostly pack ice .
20:00 the CAR was locked on nadir viewing mode to scan the icy surface.
20:37 the CV-580 entered the lower third of the stratus layer.
20:42 the CV-580 passed over the ARM site, where the CAR was able to scan lower broken stratus over broken pack ice and leads .
20:42 the CV-580 entered the middle of the stratus layer and the CAR was put in the starboard scanning mode to observe the sinusoidal pattern of the radiation in the diffusion domain. As the CV-580 climbed to the upper third of the stratus layer, the CAR was returned to nadir scanning.
20:50 the CV-580 exited the stratus layer at the top.
20:54 the CAR was put into zenith viewing mode while flying above the stratus cloud .
21:19 the CAR was put in nadir viewing mode to view the uniform cloud deck below .
21:30 while still over the stratus cloud tops, the CAR was put in zenith viewing position. Once again the CV-580 turned around and dropped back into the diffusion domain, where the CAR was put back into starboard scanning mode.
22:00 BRDF measurements over mostly pack ice and some leads, with clear skies above. We did about 5 circles with a bank of 20 degrees to the right.
22:20 we returned to level flight and the CAR was put back in nadir scanning mode, where it remained for the rest of the flight.
22:27 we flew out below the cloud deck over mainly open ocean with occasional ice.
22:29 we returned to the the ARM site and began climbing through the cloud layer again. We continued circling and climbing above the cloud deck to check cabin pressure.
22:54 we reached 20,000 MSL and began descent.
23:32 we re-entered the cloud layer above the ARM site
23:35 we exited the base of the cloud deck, and began our return to Barrow.