Drought in the Asian summer monsoon region is linked to a weakened inter-hemispheric temperature gradient

Understanding the causes of abrupt hydrologic declines in the Asian summer monsoon region is crucial. This study provides a high-resolution record of hydrological evolution in the East Asian monsoon margin since the last deglaciation. It reveals that northern and southern China experienced distinct wet and dry periods, with significant droughts in northern China linked to Northern Hemisphere ice sheets. A "southern drought-northern floods" pattern emerged in the middle Holocene, driven by the southward withdrawal of the Intertropical Convergence Zone (ITCZ) and enhanced East Asian monsoon suppression by the Hadley Circulation. The study highlights synchronous extreme droughts in the mid-to-late Holocene, emphasizing the importance of the inter-hemispheric temperature gradient in regulating these events.

Lin Chen, Jie Chen, Zhongwei Shen, Jiaju Zhao, Mengjing Li, Xianyu Huang, Jianbao Liu, Aifeng Zhou