The New Siberian Islands were the birthplace of the MOSAiC floe: the sea ice in which the research vessel Polarstern is now drifting through the Arctic was formed off the coast of the archipelago, which separates the East Siberian Sea and the Laptev Sea to the north of Siberia, in December 2018. Sediments, and even small pebbles and bivalves, were incorporated into the ice during the freezing process, which the on-going melting process has brought to light on the surface of the MOSAiC floe. This is an increasingly rare phenomenon as nowadays most of the “dirty ice” melts before it even arrives in the Central Arctic. These are among the main findings of a study that MOSAiC experts have published now in the journal The Cryosphere, and which will provide the basis for numerous upcoming scientific assessments.
At first glance, it looks like a group of people with dirty shoes had left tracks all over the snow. But in reality, they are sediments, and even small pebbles and bivalves, which the on-going melting process has brought to light on the surface of the MOSAiC floe. When the sea ice formed, they were frozen inside; accordingly, they hail from the nursery of sea ice along the Siberian Shelf, which the experts have now used a combination of model simulations and satellite data to describe in detail.
The MOSAiC floe had already drifted over 1200 nautical miles in a meandering course when the research icebreaker Polarstern moored to it on 4 October 2019, at the coordinates 85° North and 137° East, and began to drift with it through the Arctic Ocean. While the current expedition team is busy taking readings in the Arctic, their colleagues back at home are analysing the data gathered. The precise analysis confirms the first impressions from the beginning of the expedition: "Our assessment shows that the entire region in which the two ships looked for suitable floes was characterised by unusually thin ice," reports Dr Thomas Krumpen, a sea-ice physicist at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). Last autumn, the first author of The Cryosphere study coordinated research activities on the Russian icebreaker Akademik Fedorov, which accompanied the flagship of the MOSAiC expedition, the Polarstern, for the first few weeks. The Akademik Fedorov was also instrumental in deploying monitoring stations at various locations across the MOSAiC floe - collectively referred to as the 'Distributed Network'.
Read more at Alfred Wegener Institute for Polar and Marine Research
Photo: With the support of the Russian research vessel Akademik Fedorov and Russian helicopters, a Distributed Network of autonomous buoys was installed in a 40-km radius around the MOSAiC floe on 55 additional residual ice floes of similar age. CREDIT: Mario Hoppmann