The Arctic Ocean is undergoing rapid climate change. As the region warms and sea ice retreats, previously inaccessible areas become accessible, paving the way for increased activity. The water column is changing in response to freshwater inputs, modulation of inflowing Atlantic water, and a reduced sea ice cover. Observing and understanding the changes occurring in the surface layer of the Arctic Ocean is critical for its appropriate management, as processes here influence primary productivity and ecosystem dynamics in the photic zone. Moreover, the changing sea ice regime directly affects the surface layer, with increasing light availability but also increased stratification and nutrient limitation expected as the sea ice retreats. The rapid pace of change means our current understanding of the Central Arctic Ocean is outdated and needs updation to enable effective management. Although the Arctic is warming, it remains an extreme environment-cold, dark and ice-covered for much of the year, making comprehensive studies extremely challenging. However, the retreating ice cover and availability of powerful new research vessels have allowed a new sustained observing system to be established in the Central Basins.
