Xingxing Wang1, Yue Wang1, Kelsey A. Dyez2, A. Christina Ravelo3, Chunxiao Sun1, Fenghao Liu1, Xiaoying Jiang1, Zhimin Jian1
1State Key Laboratory of Marine Geology, Tongji University, Shanghai, China,
2Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA,
3Department of Ocean Sciences, University of California, Santa Cruz, CA, USA
Abstract：The Hadley Circulation and associated westerlies strengthened and moved equatorward across the mid-Pleistocene transition (MPT). However, the evolution of the intertropical convergence zone (ITCZ) is still elusive due to the scarcity of long-term hydrological records from regions sensitive to the ITCZ change. Here, high-resolution sea surface salinity estimates derived from surface-dwelling planktic foraminiferal δ 18O and Mg/Ca in Ocean Drilling Program Site 871 reveal a long-term freshening trend in the central equatorial Pacific across the MPT. We attribute this secular reorganization of the precipitation-evaporation balance to the gradual southward migration and intensification of ITCZ in the North Pacific. It is inferred that the long-term evolution of the ITCZ was modulated by the increased meridional sea surface temperature gradients and the enhancements of trade winds across the MPT.
Full Article：https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL105983
