The Penultimate Glacial Termination and Variability of the Pacific Intertropical Convergence Zone
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2019. American Geophysical Union. All Rights Reserved. Understanding how the Intertropical Convergence Zone (ITCZ) responds to abrupt climate change is essential for reconstructing large-scale atmospheric circulation across climate transitions. However, key differences between dynamical models and observational constraints on ITCZ movement remain unresolved. Here, we examine the Pb and Nd radiogenic isotope signatures of dust deposited in the central equatorial Pacific (CEP) from 160 to 105kyr. We quantified the relative contributions of Northern Hemisphere- and Southern Hemisphere-sourced dust to the CEP. In contrast with previous model estimates, we demonstrate that South America is an important source of dust to the CEP during glacial periods. Our new observations provide a critical data set for verifying dynamical arguments about tropical hydroclimate. We infer that the southernmost position of the ITCZ precipitation centroid occurs between 136 and 131kyr, coincident with the timing of North Atlantic Heinrich Stadial Event 11 (136 to129 kyr).