Science Flight #11 - May 16

The weather situation was still not what we really wanted to have. But Necessity is the mother of invention.

With now low level clouds in close distance we aimed for a wide field of mid-level clouds which was predicted south of Inuvik. As these clouds were in the range of Polar 6 we decided to mirror our previous flight strategy. Polar 6 was still intended to fly into the clouds sampling microphysical properties but this time mostly at the cloud bottom, where precipitation was expected. Polar 5 now does remote sensing from below. Therefore the lidar was configured for zenith measurements. 

Take-off again was delayed. This time not due to weather or instrumental problems but because another aircraft arriving in Inuvik had to make an emergency landing. As we learned a sign in the cockpit for the landing gears did not work. So the pilots could not be 100% sure, that the landing gear is working properly. After flying a couple of circles to burn all the remaining fuel the aircraft fortunately could land without problem. Shortly after the safe landing, Polar 5&6 started south where a rectangular pattern was flow.

As this was also the first flight above land we got a very different view of the landscape. The still frozen Mackenzie was crossed several times. And also some mountains did show up. With Polar 5 flying in about 1000 ft above the surface we sometimes had to adjust the altitude to avoid a crash. Also scientifically the flight was much more successful than expected before. Polar 6 could penetrate the clouds from below and sampled a lot of different precipitation. At the same time, the lidar on Polar 5 did record the structure of the cloud bottom where nice fall streaks (virga) were visible. 



Unfortunately, the cloud base did decrease during the flight and also the altitudes with precipitation. When Polar 5 entered medium rain, we had to switch of the lidar to close the opening in the roof before water enters the optics of the instrument. Also Polar 6 had to fly lower and lower, so we decided to stop the measurements earlier and return to Inuvik. 





For details read here: http://www.uni-leipzig.de/~racepac/flights/flight_11.html