Enhanced ventilation of Eastern North Atlantic Oxygen Minimum Zone with deglacial slowdown of Meridional Overturning

The eastern Tropical North Atlantic Oxygen Minimum Zone (ETNA OMZ) plays a critical role in marine ecosystems off northwestern Africa. One of the key controls of the ETNA OMZ is ventilation driven by the subsurface ocean circulation of the Atlantic subtropical gyres. However, how this shallow circulation interacts with changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC) remains unclear. Here, we present a deglacial and high-resolution paleo-oxygenation record (combined bottom and pore water) from the margin of ETNA OMZ (GeoB9512-5, 793 m water depth), which registers more strongly oxygenated periods during the Last Glacial Maximum (LGM), two parts of the Heinrich Stadial 1 (HS1), and during the Younger Dryas (YD). We show that steeper meridional temperature gradients during HS1 and YD associated with AMOC slowdown intensified the subsurface subtropical cell circulation and increased the oxygen supply to the ETNA OMZ.