Atlantic inflow insights from sediment core reconstructions of the Norwegian Atlantic Current over the past 1000 years

The North Atlantic Current and its extensions, including the Norwegian Atlantic Current (NwAC), transport warm and saline upper ocean waters from the North Atlantic north-eastward into the Nordic Seas. The interaction between this saline inflow versus freshwater runoff into the Arctic is important in modulating the response of the Atlantic Meridional Overturning Circulation to climate change. To better understand variability in the strength and character of this inflow and the closely linked North Atlantic Subpolar Gyre, paleoceanographic reconstructions aim to extend the limited temporal scope of existing instrumental records. Here, we present high-resolution reconstructions of temperature and salinity from coupled d¹⁸O – Mg/Ca measurements on two species of planktonic foraminifera, as well as estimates of upper-ocean radiocarbon ages from a rapidly accumulating marine sediment core located under the NwAC (GS06-144-22; 62.5ºN, 4.1ºE, 921m). Using a novel, robust chronology for this core, we determine changes in the surface radiocarbon reservoir effect at the site, which - along with the seasonal temperature and salinity reconstructions - provide new insights into NwAC and Subpolar Gyre dynamics over the last millennium.