Origin of δ13C minimum events in thermocline and intermediate waters of the western South Atlantic

Stable carbon isotopic (δ13C) minimum events have been widely described in marine archives recording the properties of thermocline and intermediate waters during glacial terminations. However, mechanisms associated with these remain ambiguous. Here we present three high temporal resolution deep-dwelling planktonic foraminifera δ13C records from main one benthic record modern core Antarctic Intermediate Water (AAIW). Our sediment cores are distributed along western South Atlantic equator to subtropics, longest spanning last ∼300 kyr. The results show that were pervasive features terminations Marine Isotope Stage 4/3 transition Atlantic. Two distinct responsible for minima at depths Atlantic, respectively. We suggest mostly driven by thermodynamic ocean-atmosphere equilibration, which is supported calculated dissolved inorganic subtropical as well previously published model simulations. On other hand, tropics likely caused slowdown meridional overturning circulation accumulation isotopically light mid Ocean.