Science Flight #8 - May 11

Clear sky conditions were forecasted for wide areas around Inuvik. This was the first chance to perform the clear sky mission as proposed for RACEPAC. Although the satellite images showed a little smaller cloud free area, we found perfect conditions over the beaufort sea. As some clouds might appear in the area all PMS probes were operated during the flight. In Polar 5 the configuration of the AMALi lidar was changed for zenith view for this flight. Take-off was scheduled for early afternoon as the cloud free area was forecasted to increase during the day.

For the clear sky mission, Polar 5 and Polar 6 operated individually. The aim of Polar 5 was to measure as much different surface albedo as possible while Polar 6 flight was intended to characterize aerosol and trace gas in different altitudes. For this purpose, two "curtains" with nine different altitudes were flown by Polar 6. One above the ocean, one above the ground station in Tuk. The results were interesting. Different to mid-latitudes enhanced aerosol was found in the uppermost atmospheric layers. This is common as there are just no big aerosol sources in the arctic and transport of aerosol happens in higher altitudes. 

Polar 5 could cover a wide area with different sea ice conditions. Although no completely closed sea ice was found anymore. Therefore, melting did just progress to fast the last days. However the measurements will be very useful. Above one 50 miles leg, Polar 5 flow in four different altitudes which allows to investigate the impact of surface heterogeneity. 

In general Polar 5 was flying very low today. This is required for the albedo measurements but also for the lidar system, which was turned into zenith view for this mission. In the quicklooks of AMALi no significant aerosol layer could be observed. The atmosphere was rather well mixed. The low flight level also has another advantage. The flight is very scenic. Flying over the ice flows with all the big ridges is very impressive. Even wildlife could be observed. Mostly birds, we (especially the pilots) saw also a moose, seals and a polar bear. 

For details read here: http://www.uni-leipzig.de/~racepac/flights/flight_08.html