comfortable at four degrees Celsius. It has mi- grated from the increasingly warmer North Sea and North Atlantic to the north in the past years and now Clear signs: The Kongsfjord on Spitsbergen displays a [...] most clearly in the constantly declining sea ice cover. Scientists presume that the North Pole could be ice-free in summer in less than 40 years. The melting sea ice opens up new opportunities for some [...] than the Atlantic sea butterfly. It, too, came to the Fram Strait with the warmer Atlantic water. In contrast to the sea butterfly, however, it has now managed to reproduce in the far north, too, as AWI biologists

transect, Polarstern bit its way through heavy sea ice, hard as concrete and covered with a thick layer of snow. This altogether slowed down our progress into the north significantly. During our journey in the

we started in the marginal sea ice zone east of Svalbard, and then set course north into the central Arctic Ocean.The marginal sea ice zone was mostly covered with decaying sea ice and some larger ice-free

field and conditions turned out to be ideal for a boundary layer mission north of Svalbard. It turned out to be a typical day with sea ice melt due to strong warm air advection by southerly winds. Atmospheric [...] List of general, very preliminary conclusions from the campaign Sea ice extend, Polarstern position and measurement time - This year the sea ice extended more to the south than in the years before. Therefore [...] campaign objective was to collect data of surface reflectivity in cloudless conditions in different sea ice situations. 2. Summary of daily activities Mon, 19 June This day was used for downloading and checking

Svalbard. Subsidence in a high pressure system was supposed to spread the cloud free area towards north over the sea ice, where the position of the Polarstern position was predicted. During both satellite overpasses [...] and P6. The purpose was to investigate cloud properties developing over sea ice, and to follow their transition to the open sea. The cloud situation was such that we had to fly high above the observed [...] Meeting #8: Double A-Train overpass A 5.2 5.3 17 June 2017 Clouds above sea ice and open water A 5.5 5.6 18 June 2017 PS #9: Clouds above sea ice and water A 5.6 5.7 Total campaign flight hours this week: 24

week a high pressure system was located exactly over Svalbard and transported warm and moist air north-eastward. In this air mass, low level clouds and sometimes fog were present over a wide area. This [...] A-Train satellite 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 [...] very thin and patchy. Therefore, the Polarstern was left earlier and clouds southwards close to the sea ice edge were investigated by Polar 6. Polar 5 passed Ny Alesund on the way home. Fri, 09 June The general

expected to arrive the sea ice north-west of Svalbard during the day. Cloud cover was predicted to be low in this area providing the chance to measure the surface properties of the sea ice with Polar 5 and [...] Polarstern could not move fast in the thick sea ice, this gave us the opportunity to meet Polarstern in relative close distance to Longyearbyen, but already over sea ice. Coordination with Polarstern worked [...] Config Air time Flight time 29. May 2017 Thin low level clouds over sea ice A 2.9 3.0 31. May 2017 PS Meeting: Thin low clouds over sea ice B 3.8 4.5 02. June 2017 PS Meeting and CloudSat overpass A 5.5

million square kilometres, the Arctic Ocean also includes large shallow shelf seas, such as the Laptev Sea and Barents Sea north of Russia. Large parts of the Arctic Ocean are fully or seasonally ice covered [...] Ocean. The extremely low sea ice extent in September 2012 is shown as a white/blue area. The pink line indicates the mean sea ice extent in February, the yellow line the mean sea ice extent in September [...] years has been shrinking at unexpected rates. The sea ice is transported from the shelves via transpolar drift into the Fram Strait, the only deep-sea connection between Arctic and Atlantic Ocean. Photo:

the ecosystem The North Sea in the fast lane of change 24 Photo: S. Zankl 25 North Sea in the fast lane of change? Long-term investigations off Helgoland provide proof: the North Sea has become warmer [...] visitors first-hand insights into the habitat of the Wadden Sea. AWI’s North Sea office develops strategies for sustainable use of the North Sea in conjunction with the political needs and interests of [...] the future of the North Sea habitat? Transparent and fairy-like, Mnemiopsis leidyi, also known as the “sea walnut”, looks harmless. When this comb jellyfish appeared in the North Sea for the first time

2017
4 January 2017, 2 weeks and 5 days at sea. The morning finds Polarstern alongside the ice shelf edge, or, more precisely, at the north-eastern berth of Atka Sea Port.