Prof. Dr. Klaus Dethloff (Alfred-Wegener-Institut, Sektion Physik der Atmosphäre, Potsdam)
Research vessel Polarstern will drift with the sea ice across the central Arctic. The drift starts in the Siberian sector of the Arctic in late summer and will be supported by the Russian ice breaker Fedorov to search for a suitable and stable enough sea ice floe. A distributed regional network of observational sites will be established in an area of up to 50 km distance from research vessel Polarstern, representing a grid cell of climate models. The ship and the surrounding network will drift with the natural sea ice drift across the Arctic cap towards the Atlantic.
The rapid changes in the Arctic lead to an urgent need for more reliable informations about the state and evolution of the Arctic climate system. This requires more accurate observations over various spatial and temporal scales and across a wide variety of disciplines. Observations of many critical and important parameters never were made in the central Arctic for a full annual cycle. The focus of MOSAiC lies on in-situ observations of climate- and weather processes that couple atmosphere, ocean, sea ice, biogeochemistry and ecosystem. These measurements will be supported by weather and sea ice predictions and remote sensing operations to make the expedition successful. The expedition includes aircraft operations and cruises by icebreakers from Russian, Chinese and Swedish MOSAiC partners.
All observations will be used for the main scientific goals of MOSAiC, enhancing the understanding of the regional and global consequences of Arctic sea ice loss and improve weather prediction models and climate models. The results are needed to advance the data assimilation for numerical weather prediction models, sea ice forecasts and climate models and ground truth for satellite remote sensing.
A unique hierarchy of local, regional and global models will be applied, to interpret the MOSAiC measurements and to improve the models performance in the Arctic. The understanding of energy budget and fluxes through interfaces, sources, sinks and cycles of chemical species, boundary layer processes, and primary biological productivity is another important topic during the expedition.