High resolution, multi-proxy analysis of the Younger Dryas Stadial section of Lake Suigetsu sediments@en

The Younger Dryas Stadial (YDS) was an episode of northern hemispheric cooling which occurred within the Last Glacial Interglacial Transition (LGIT). A major driver for the YDS climate was a weakening of the Atlantic Meridional Overturning Circulation (AMOC). It has been inferred that the AMOC began to strengthen mid-YDS, producing a bipartite structure of the YDS in records from continental Europe. These records imply that the polar front and westerlies shifted northward, producing a warmer second phase of the YDS in Europe. Here we present multi-proxy data from the sediments of Lake Suigetsu (Japan), as evidence that a related bi-partition of the YDS also occurred in East Asia. Besides showing for the first time that the bi-partition was not limited to the North Atlantic/European region, the data also imply a climatic dipole between Europe and East Asia since the cold-warm characteristics are reversed at Lake Suigetsu. We suggest that changes in eastward moisture transport from the North Atlantic are the primary mechanism by which the teleconnection can be explained.新仙女木冷期（Younger Dryas Stadial, YDS）是发生于末次冰期向间冰期过渡时段（Last Glacial Interglacial Transition, LGIT）内的一次北半球降温事件。其气候演化的核心驱动因素为大西洋经向翻转环流（Atlantic Meridional Overturning Circulation, AMOC）的减弱。已有研究推断，AMOC在YDS中期开始增强，使得欧洲大陆的气候记录呈现出YDS的二分结构特征。相关记录表明，极锋与西风带向北迁移，致使欧洲地区YDS的第二阶段气候相对温暖。本文报道了采自日本水月湖（Lake Suigetsu）沉积物的多代用指标数据，以此证实东亚地区同样存在YDS的二分结构。本研究首次证明，YDS二分现象并非仅局限于北大西洋/欧洲区域；同时，数据还揭示了欧洲与东亚之间存在气候偶极子特征——两地在YDS冷暖特征上恰好相反，该差异在水月湖的沉积记录中得以体现。我们认为，源自北大西洋的东向水汽输送变化是解释这一遥相关现象的核心机制。