Скачать или смотреть Interannual Variability and Precursors to Sea Ice Conditions at the Start of MOSAiC Expedition

Interannual Variability and Precursors to Sea Ice Conditions at the Start of MOSAiC Expedition in 2019 - 2021

Vasily Smolyanitsky, Arctic and Antarctic Research Institute

Sea ice conditions that have occurred at the start of MOSAiC expedition in 2019 and have arisen in Eurasian Arctic due to precursors in atmosphere and polar ocean during summer 2019 defined background for setting the Distributed Network (DN) and many of ice properties recorded during the expedition. Sea ice conditions within the area in 2019 due to record surface air temperatures (SAT) and high upper ocean heat content (HC) led to highly deteriorated residual ice with thicknesses 50-70 cm. That complicated search of the floes and defined fast Polarstern poleward drift with observations on a weakened fast-growing first-year and second-year ice. By summer 2020 sea ice conditions in this region were characterized by even weaker ice due to both greater SAT and HC anomalies including that to 2019. Located at a typical distance of ~50100 km from the ice edge (200250 km in 2019) the area was absolutely inapplicable for MOSAiC goals. However, the sea ice conditions in 2021 appeared strikingly different due to zero or negative SAT and HC anomalies (relative both to 1991-2020 period and 2019-2020). Ice cover in the region following shipborne and CryoSAT-2 observations was at a distance of 300400 km from ice edge in a form of vast floes 100150 cm thick and was experiencing much slower drift following information from YOPP buoys. Start of MOSAiC expedition in 2021 as well as in next 2022 would lead to other DN setting and longer expedition drift with ice observations on mostly second-year ice.