The Asian Summer Monsoon: Teleconnections and Forcing Mechanisms—A Review from Chinese Speleothem δ 18 O Records

• Published in: Quaternary
• Main Authors: Haiwei Zhang, Yassine Ait Brahim, Hanying Li, Jingyao Zhao, Gayatri Kathayat, Ye Tian, Jonathan Baker, Jian Wang, Fan Zhang, Youfeng Ning, R. Lawrence Edwards, Hai Cheng
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2019
• Subjects: ASM; SISAL; speleothem; oxygen isotope; paleoclimate; China; Human evolution; GN281-289; Stratigraphy; QE640-699; North Atlantic
• Online Access: https://doi.org/10.3390/quat2030026; https://doaj.org/article/b16445daa3c74f399a48dba10a12ab6e

Asian summer monsoon (ASM) variability significantly affects hydro-climate, and thus socio-economics, in the East Asian region, where nearly one-third of the global population resides. Over the last two decades, speleothem δ 18 O records from China have been utilized to reconstruct ASM variability and its underlying forcing mechanisms on orbital to seasonal timescales. Here, we use the Speleothem Isotopes Synthesis and Analysis database (SISAL_v1) to present an overview of hydro-climate variability related to the ASM during three periods: the late Pleistocene, the Holocene, and the last two millennia. We highlight the possible global teleconnections and forcing mechanisms of the ASM on different timescales. The longest composite stalagmite δ 18 O record over the past 640 kyr BP from the region demonstrates that ASM variability on orbital timescales is dominated by the 23 kyr precessional cycles, which are in phase with Northern Hemisphere summer insolation (NHSI). During the last glacial, millennial changes in the intensity of the ASM appear to be controlled by North Atlantic climate and oceanic feedbacks. During the Holocene, changes in ASM intensity were primarily controlled by NHSI. However, the spatio-temporal distribution of monsoon rain belts may vary with changes in ASM intensity on decadal to millennial timescales.