Changes in the global ocean during the last deglaciation

MUGLIA, JUAN; MULITZA, STEFAN; REPSCHLÄGER, JANNE; SCHMITTNER, ANDREAS

Buenos Aires

Workshop; Summer Workshop: Iron supply in the Patagonian shelf-break front: Malvinas Current and the interaction with slope sediments and submarine canyons; 2024

Universidad de Buenos Aires

The early last deglaciation (~19-15 ky BP) was a period of rapid climate change. It is characterized by theonset of atmospheric CO2 rise and land ice reduction that eventually lead to the Holocene climate state.The ocean processes involved in deglacial climate change are still under debate, with freshwater fluxes indifferent basins, changes in winds, ocean circulation, and biogeochemistry, as possible drivers of carbontransfer from the deep ocean to the atmosphere. Carbon isotopes in benthic foraminifera samples fromsediment cores show variations during the early last deglaciation, that act as tracers of changes in deepwater mass structure, ventilation, and export production. Here we compare the global deglacial benthicforaminifera δ13C database from the Ocean Circulation and Carbon Cycling (OC3) project with differenttransient global, isotope enabled, ocean model simulations. The goal is to constrain the different oceanchanges that can explain variations in δ13C during the early last deglaciation. We use a novel approach,where a global synthesis of benthic foraminifera δ13C is compared one-to-one with modeled δ13C fromtransient simulations, with both spatial and time dimensions taken into account in a four-dimensionalanalysis.