water masses from the North Atlantic into the European marginal seas of the Arctic Ocean plays a significant role in the marked decrease in sea-ice growth, especially in winter. Sea-ice physicists from the [...] growth in the Barents and Kara Seas for years. Furthermore, they demonstrate that the invasion of warm Atlantic water masses further east, at the northern edge of the Laptev Sea, can have such a long-term [...] thickness that the effects are evident a year later, when the ice has drifted towards Greenland via the North Pole and leaves the Arctic through Fram Strait. This study also includes data from the MOSAiC expedition