Rapid Climate Links Between High Northern Latitudes and Tropical Southeast Asia Over the Last 40 ka

• Published in: Geophysical research letters Vol. 50; no. 24
• Main Authors: Huang, Jie, Wan, Shiming, Chang, Fengming, Liu, Jianxing, Yang, Zaibao, Sun, Hanjie, Ma, Xiaochuan, Li, Anchun, Li, Tiegang
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 28.12.2023; Wiley
• Subjects: Climate change; Climate feedback; Climatic extremes; Composition; Continental shelves; Convergence; Convergence zones; Deposition; East Asian monsoon; East Asian winter monsoon; Environmental risk; Flood risk; Floods; Global climate; Global warming; Gravity; high northern latitudes; Intertropical convergence zone; Latitude; Marine sediments; Monsoons; New records; Northern Hemisphere; Oscillations; Rivers; Sea level; sea level change; Sea level changes; Sea level rise; Sediment; Sediments; Terrigenous sediments; tropical Southeast Asia; Wind; Winter; Winter monsoon; Southeast Asia; Borneo
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL107171

The climate response of tropical Southeast Asia to abrupt climate change originating from high northern latitudes remains poorly understood. Here, marine sediments recovered from the Northwest Borneo Trough are analyzed to trace variations in terrigenous material composition associated with sea level and palaeoflood activities over the past 40 ka. We describe for the first time the influence of sea level change on terrigenous deposition from a tropical island with small mountainous rivers surrounded by narrow continental shelves and the coupling between North Atlantic dynamics and climate feedbacks in tropical Southeast Asia during the Dansgaard‐Oeschger stadials. This study demonstrates that climate oscillations occurring at high northern latitudes can be transmitted to tropical Southeast Asia through the functions of sea level, the East Asian winter monsoon and the Intertropical Convergence Zone. Such information is fundamental to correctly assessing future sea level rise and flood risks in tropical Southeast Asia. Plain Language Summary Sea level rise and extreme climate events are two global climate issues currently faced by humanity under the background of global warming. However, the climate feedbacks in tropical Southeast Asia remain unknown, although portions of this region are now densely populated. Here, a gravity core retrieved from the Northwest (NW) Borneo Trough is employed to reveal variations in terrigenous material composition and their controlling factors over the past 40 ka. We found that the terrigenous sediments delivered to the NW Borneo Trough are primarily sourced from NW Borneo, and their deposition is mainly controlled by sea level change and flooding. Further in‐depth analysis reveals that northern high‐latitude cooling could cause floods in NW Borneo both in the modern and during the past by influencing the East Asian winter monsoon (EAWM) and/or the Intertropical Convergence Zone (ITCZ). Furthermore, our new records suggest that a stronger EAWM during cold stadials could have transported high levels of northerly moisture to NW Borneo, resulting in relatively higher speleothem δ18O values in NW Borneo. In short, abrupt climate changes in the high‐latitude Northern Hemisphere can be transmitted to tropical Southeast Asia through the functions of sea level, the EAWM and the ITCZ. Key Points Sea level change and flooding are the main controlling factors for terrigenous deposition from tropical Southeast Asia Northern high‐latitude cooling could lead to the outbreak of floods in Northwest Borneo via atmospheric teleconnection Climate oscillations occurring at high northern latitudes can be transmitted to tropical Southeast Asia