Science Flight #9 - May 13

Today only Polar 6 was in the air while the Polar 5 crew still could get some rest. Stable high pressure conditions did bring no low clouds in the area but a very thick cirrus field which did not allow reasonable good radiation measurements for a second clear sky mission. Polar 6 instead repeated the flight pattern from May 11 profiling the atmosphere at two locations with a ''curtain'' of horizontal legs in different altitudes.

The first profile was flown somewhat further north compared to the last flight above sea ice while the second profile again was located close to Tuk. However, there was a closed unstructured, diffuse cloud deck (low altostratus) around 20000 ft altitude, probably with 8/8 coverage present throughout the entire flight. It was optically fairly thick although the sun could be seen through at times. Outbound North the approaching frontal system can be seen to the West like a cloud wall.

During the profiling legs at 10000 ft, 8000 ft, 6000 ft, 4000 ft, 3000 ft, 2000 ft, 1500 ft, 1000 ft and 500 ft, were flown. In general higher aerosol concentrations were found compared to May 11. The highest concentrations were not measured at ground level but in the higher legs of the profile.



For details read here: http://www.uni-leipzig.de/~racepac/flights/flight_09.html