was used to compile drafts of the next flight pattern and to prepare for the first meetings with Polarstern. 3. Flight Summary Polar 5 Date Subject Config Air time Flight time 10. May 2017 Test flight A

clouds at Polarstern. Tue, 06 June Due to a weather front passing Svalbard, no flight was scheduled and a day-off was announced. Wed, 07 June The weather front shifted towards the area of Polarstern and did [...] overpass and cloud measurements at Polarstern was planned. The cloud cover over the sea ice was predicted to decrease during the day. When P5/6 arrived at Polarstern, the clouds were very thin and patchy [...] This situation was used to take a day-off on Tuesday. The polar aircraft reached two times RV Polarstern where collocated measurements could be performed. In the second part of the week a high pressure

online and off-line instrumentation (high volume and size-resolved samplers), was installed on Polarstern on the upper deck to measure in-situ atmospheric aerosol physical-chemical properties.

Thursday flight plans to Polarstern were again cancelled due to bad weather. On all other days joint Polar 5 and 6 flights could be flown; including three more meetings with RV Polarstern. Unfortunately, the [...] to the campaign. Boundary layer profiles could be measured at 5 separate locations downwind of Polarstern which would not have been possible with a single polar aircraft. The extended duration of Polar [...] with a well-defined layer of low-level clouds and scattered clouds above dominated the area of Polarstern. This situation was used to extensively probe the boundary layer along the northerly flow at different

The MOSAiC Expedition
Two-and-a-half years from now, the research vessel Polarstern will depart on an adventurous expedition. For an entire year, the ship will drift through the Arctic, stuck in the

aircraft people at Polarstern and vice versa that of the PS-people at the airport had to be planned. We also organized a get-together for the evening of Wednesday of both the Polarstern and the aircraft [...] Sea ice extend, Polarstern position and measurement time - This year the sea ice extended more to the south than in the years before. Therefore, it was feasible for us to reach Polarstern with Polar 5 and [...] prevailing northerly winds. Collocation with Polarstern and Ny Ålesund - We actually succeeded ten times to perform collocated measurements with both aircraft, Polarstern, and partly with observations from an

nary physical, biological and biogeochemical partners, wales and seals occasionally approached Polarstern.

PS106/2 - Weekly Report No. 7 | 2 - 9 July 2017
During our northward transect, Polarstern bit its way through heavy sea ice, hard as concrete and covered with a thick layer of snow. This altogether

2017
After concluding our 4 th ice station at the northernmost location of this expedition, Polarstern set a south-westerly course, heading for the position of our well-known PASCAL ice floe of PS 106/1 [...] mostly gentle passage through the ice. Our journey was inter-spaced with stations where we set out Polarstern’s rubber boats Laura and Luisa to sample the surface microlayer, conducted CTD casts and performed

departed from Tromsø and enjoyed the marvellous weather. The sun was shining from a blue sky while POLARSTERN passed the fjords towards the North-Atlantic. Finally, we are let loose. In particular, the newbies