NOAA/WDS Paleoclimatology - Huangyuan Cave, North China d18O Data from 8370-7980 Years BP

The 8.2 ka event has been extensively studied, whereas its structure is ambiguous in North China. Here we present a high-resolution (~1 year) d18O record from annual laminated speleothem from Beijing to characterize the detailed variability across this event in North China. Our record indicates a dry 8.2 ka event spanning 8.254-8.107 ka BP with a two-stage structure superimposed by three prominent high d18O excursions. The identical structure of speleothem d18O records between North and central China during the event suggests a common forcing/response in East China, whereas the progressively increased offset between their average values may reflect changes in moisture source or rainout effect. A close comparison with the Greenland ice core records suggests a strong linear response of the Asian summer monsoon to the North Atlantic climate changes across the early and middle stages of the event, but a different mechanism in the termination process.

8.2千年事件（8.2 ka event）已得到广泛研究，但其在华北地区的结构特征仍存在歧义。本研究基于北京地区年纹层状洞穴沉积（speleothem）的高分辨率（~1年）δ¹⁸O记录，揭示了该事件在华北地区的详细变化特征。我们的记录显示，距今（Before Present，BP）8254~8107年的8.2千年事件整体偏干旱，且呈现两阶段结构，叠加了三次显著的δ¹⁸O正偏移。事件期间华北与华中地区洞穴沉积δ¹⁸O记录的结构一致性，指示中国东部存在共同的气候强迫与响应机制；而两者平均值之间的差值逐渐增大，则可能反映了水汽源区或降水洗脱效应的变化。与格陵兰冰芯（Greenland ice core）记录的对比分析显示，亚洲夏季风（Asian summer monsoon）在该事件的早、中期阶段对北大西洋气候（North Atlantic climate）变化呈现强烈的线性响应，但在终止阶段的作用机制存在差异。