Atlantification at the Gateway of the Arctic Ocean over the Last Thousand Years

Atlantification is a major process driving rapid changes in the Arctic Ocean, e.g., sea-ice loss, warming andsalinification of the near-surface, enhanced mixing and changes in the ecosystem structure. The recentscientific literature highlights the importance of the transport of Atlantic water as a cause of Atlantification,but fundamental climatic processes driving this phenomenon are far from being fully understood.Moreover, most studies focused on the analysis of recent observational data covering the last decades,while recent studies showed that Atlantification had started in the 19th century. In this contribution, we illustrate scope and progress of the Italian funded project “ATTRACTION: Atlantification dRiven by polAr-subpolar ConnecTIONs in a changing climate”. The project aims to provide a historical perspective on Atlantification by integrating observational evidence over the last decades, paleo-reconstructions and numerical paleoclimate simulations covering the past several centuries. We assess the capability of available tools to robustly describe coupled dynamics at the gateway of the Arctic Ocean (Fram Strait and Barents Sea), and their variations over multi-centennial periods. Furthermore, we provide a solid past reference for attribution of the ongoing Atlantification and discuss how paleoclimate simulations could support the identification of key locations for proxy-based reconstruction of the Atlantification. Toward a mechanistic understanding of Atlantification-like events over the last millennium, our assessment focus on the role of heat and salt redistribution by sub-polar dynamics by its major controls, including the Atlantic Multidecadal Overturning Circulation, the Sub-Polar Gyre and the Greenland Sea Gyre.