Western boundary current in relation to Atlantic Subtropical Gyre dynamics during abrupt glacial climate fluctuations

摘要: Abstract Ocean-atmosphere simulations corroborate the relationship between tropical Atlantic subsurface heat and salt storage driven by Salinity Maximum Water (SMW) deglacial perturbations of Meridional Overturning Circulation (AMOC). Whether AMOC variability last glacial cycle affected SMW export into West remained yet elusive. In order to assess sensitivity hydrography during abrupt rapid climatic oceanic perturbations, we present century-resolving foraminifera-based (~200 m water depth) temperature salinity reconstructions from Tobago Basin core M78/1–235-1. The proxy records were interpreted in terms closely related development North Brazil Current (NBC) Subtropical Gyre (STG) ~37 30 ka BP, relation their developments. Prior ~32.8 ka cyclic variations conditions attributed NBC, which acted line with a recurrent intensification relaxation trade winds, subtle migrations Intertropical Convergence Zone, moisture transport across Central America. Major re-organizations upper ocean-atmosphere system took place at BP and ~ 21.8 ka unmirrored major changes. Thresholds for sufficient accumulation STG allow formation intensified dispersal not achieved before late HS1, when weakening, according backlog surface warming maximum Northern Hemisphere insolation together.