全新世金钉子型气候突变事件：我国季风区湖泊记录

随着全新世划分方案于去年8月获得国际地科联官方批准，全新世金钉子型气候突变事件（8.2和4.2 ka BP事件）成为全球变化研究的前沿热点。近20年，我国全新世气候突变研究取得丰硕成果，但关于8.2和4.2 ka BP事件的区域模态、空间分异及其行为差异仍知之甚少。本项目选择我国季风区三大单元的代表性湖泊岱海、湖光岩、云龙天池为研究对象，开展湖泊岩芯的多技术年龄测定和多学科指标分析，建立湖区高分辨率全新世气候变化序列，构建不同单元全新世气候变化集成序列；辨识我国季风区8.2和4.2 ka BP事件，揭示其性质、结构与空间表现，模拟其动力过程与驱动机制，阐明其成因以及在我国季风区的传输机理。此外，开展上述湖泊沉积的成分与结构研究，建立我国季风区全新世湖泊地层层型剖面。我国季风区8.2和4.2 ka BP事件的深入系统研究，将为构建地球系统科学框架奠定理论基础、为评估未来气候突变提供科学依据。

With the formal ratification of a subdivision of the Holocene Epoch by IUGS last Augsut, two GSSP-typical, abrupt climate events, i.e., 8.2 and 4.2 ka BP events, has become the frontier and hot issue in the field of global change research. During the last two decades, a great achievement has been acquired in the research of Holocene abrupt climate changes in China; however, the regional modes and spatial patterns of both 8.2 and 4.2 ka BP events as well as differences in the behavior of two events remain poorly understood. In this project, we select Daihai, Huguangyan and Yunlong Lakes respectively from three zones of the monsoon region of China for multi-technological age dating and multi-disciplinary proxy analysis of lakes' sediment cores to establish high-resolution time series of Holocene climate changes in the lake regions and further to generate integrated sequences of Holocene climate changes for three different zones. We aim at 1) identifying 8.2 and 4.2 ka BP events occurring in the monsoon region of China; 2) revealing the nature, structure and spatial expression of the events; and 3) modelling the dynamic process and forcing mechanism of the events and elucidating both's origin as well as transmission mechanism in the monsoon region of China. In addition, the lakes' sediment cores will be analyzed for composition and texture to set up a Holocene lacustrine stratotype section in the monsoon region of China. The intensive and systematic research on 8.2 and 4.2 ka BP events occurring in the monsoon region of China would lay the theoretical foundation for forming the framework of Earth system science and also provide the scientific evidence for evaluating abrupt climate changes.