Coupled atmosphere-ice-ocean dynamics during Heinrich Stadial 2

• Main Authors: Dong, Xiyu, Kathayat, Gayatri, Rasmussen, Sune O., Svensson, Anders, Severinghaus, Jeffrey P., Li, Hanying, Sinha, Ashish, Xu, Yao, Zhang, Haiwei, Shi, Zhengguo, Cai, Yanjun, Pérez-Mejías, Carlos, Baker, Jonathan, Zhao, Jingyao, Spötl, Christoph, Columbu, Andrea, Ning, Youfeng, Stríkis, Nicolás M., Chen, Shitao, Wang, Xianfeng, Gupta, Anil K., Dutt, Som, Zhang, Fan, Cruz, Francisco W., An, Zhisheng, Edwards, R. Lawrence, Cheng, Hai
• Other Authors: Asian School of the Environment
• Format: Article
• Language: English
• Published: 2023
• Subjects: Social sciences::Geography::Environmental sciences; Heinrich Event; Oxygen Isotope
• Online Access: https://hdl.handle.net/10356/170825
• Institution: Nanyang Technological University

Our understanding of climate dynamics during millennial-scale events is incomplete, partially due to the lack of their precise phase analyses under various boundary conditions. Here we present nine speleothem oxygen-isotope records from mid-to-low-latitude monsoon regimes with sub-centennial age precision and multi-annual resolution, spanning the Heinrich Stadial 2 (HS2) - a millennial-scale event that occurred at the Last Glacial Maximum. Our data suggests that the Greenland and Antarctic ice-core chronologies require +320- and +400-year adjustments, respectively, supported by extant volcanic evidence and radiocarbon ages. Our chronological framework shows a synchronous HS2 onset globally. Our records precisely characterize a centennial-scale abrupt "tropical atmospheric seesaw" superimposed on the conventional "bipolar seesaw" at the beginning of HS2, implying a unique response/feedback from low-latitude hydroclimate. Together with our observation of an early South American monsoon shift at the HS2 termination, we suggest a more active role of low-latitude hydroclimate dynamics underlying millennial events than previously thought.