Over the night a ridge of high pressure with cloud free area passed Inuvik. The cloudless sky remained during the morning with some higher clouds moving slowly in. An early clear sky flight was scheduled to again sample aerosol and trace gas profiles in the same air mass sampled the day before. The flight track was chosen to go straight to the south and sample four times on the same leg between C1 and C2, the only area identified as cloud free on the latest satellite images.

The configuration of AMALi on Polar 5 was not changed due to the limited time before take-off. Therefore aerosol sampling of AMALi, still in nadir configuration, had to be performed flying in high altitude again. Unfortunately, during preparation for take-off the conditions for clear sky radiation measurements already got worse. After departure the high and also midlevel clouds moved faster than expected. Polar 5 tried to stay below the cloud bottom and continue sampling the cloud free atmosphere below. But decreasing cloud ceiling made Polar 5 descend further and further until no useful lidar measurements could be performed anymore. Also flying above the midlevel cloud did not work out. Consequently Polar 5 returned to Inuvik already after the first two legs and releasing two drop sondes at the waypoints C1 and C2.

Polar 6 intended to fly two profiles along the leg between the two waypoints C1 and C2. During the ferry and the first two legs Polar 6 climbed in steps from 1,500 ft to 10,000 ft. At the highest level the midlevel clouds have already reached the measurement area so that Polar 6 did enter the cloud. Due to the risk of icing the 10,000 ft leg was shorten. Climbing down at 8,000 ft still the cloud bottom was scratched providing some data for the cloud particle instruments. The second downward profile was flown over the same track and again down to 1,500 ft. This altitude was kept until landing in Inuvik.