data throughout all seasons from the very remote regions in the Arctic and Antarctic. Our autonomous platforms, or more generally speaking ‘ice tethered platforms’, are installed on sea ice and in general [...] to continue monitoring the atmosphere, snow, sea ice, and upper ocean. Often, we simply call them ‘buoys’ although most of these systems are not able to float and depend on solid ice. We are using [...] used in various ways for many similar types of sensors utilized in ocean sciences, including a drogue to make the surface unit drift with the ocean currents and less with the wind. Our main application is

marine ecosystems must always keep the polar regions in mind. The Arctic and Antarctic, for example, play a central role in the system of global ocean currents, and the large but shrinking ice sheets are

heterogeneity and temporal evolution of surface properties of the Arctic Ocean influence the radiative energy transfer through the coupled compartments (atmosphere, sea ice, open ocean) of the Arctic [...] heat release in most parts of the Arctic. Recent observations indicate, however, that in some regions major changes are taking place in the upper layers of the Arctic Ocean [...] ocean-sea ice model (North Atlantic Arctic Ocean Sea Ice Model, NAOSIM) show a destabilisation of the halocline due to increased freezing

area into the Eurasian shelf seas. Ocean waters with salinities below the average salinity of the Arctic Ocean also contribute positively to the fresh water balance of the Arctic Ocean. Such waters flow in from the Nordic Seas. An interchange of waters between the Arctic and the Nordic seas results in in sea [...] : Alfred-Wegener-Institut) Figure 1: Surface circulation of the Arctic Ocean (Graphic: Alfred-Wegener-Institut) Figure 2: Mid-depth circulation in the Arctic Ocean, which is fed from the Atlantic. 129

. However, this approach neglects all feedbacks of the sea ice-ocean system on the atmosphere. Since 2015 the initial state of the sea ice-ocean model is constrained by sea ice observations (data [...] und Gerdes, R., 2019a: Simultaneous Parameter Optimization of an Arctic Sea Ice–Ocean Model by a Genetic Algorithm, doi.org/10.1175/MWR-D-18-0360.1 Sumata, H., Kauker, F., Karcher, M. und Gerdes, R., 2019b: Covariance of Optimal Parameters of an Arctic Sea Ice–Ocean Model, doi.org/10.1175/MWR-D-18-0375.1

Gradient in the Early Eocene in the Subsurface Rather than Surface Ocean Layering of surface snow and firn at Kohnen Station, Antarctica - noise or seasonal signal? Assessing performance and seasonal bias [...] TEXH86 and UK’37 Long-term winter warming trend in the Siberian Arctic during the mid- to late Holocene Back from Antarctica Ocean surface temperature variability: Large model–data differences at decadal

up the research camp for their one-year-long drift through the Arctic Ocean. Consequently, one of the most important milestones in the expedition has been reached ahead of schedule, and before the Polar

Marine Pollution
Working in the Arctic Fram Strait, scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have found microplastic [...] findings, the two main ocean currents in Fram Strait transport the microscopically small plastic particles into the region between Greenland and Spitsbergen from both the Arctic and the North Atlantic. While passing through the Strait, many particles eventually drift to the seafloor, where they accumulate.

the one-year-long MOSAiC expedition and its research on the ocean, ice and atmosphere in the Arctic. Earlier this week, their predecessors from Leg 3 returned to Bremerhaven on board the research

Anniversary
40 years of research in the Arctic, Antarctic and in coastal regions: on 15 July, the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) [...] for climate research in the two polar regions and the world’s oceans.