(Table 1) Age determination of sediment core MD04-2845@en

Terrestrial and marine proxies (pollen, planktic and benthic foraminiferal oxygen isotopes, alkenone- and foraminifer-derived sea-surface temperatures (SSTs), ice-rafted debris) from IMAGES deep-sea cores MD95-2042 and SU81-18 (37°N, 10°W), MD99-2331 and MD03-2697 (42°N, 9°W), and MD04-2845 (45°N, 5°W) show that western European and offshore environments were strongly affected by Dansgaard-Oeschger (D-O) and Heinrich (H) events. We concentrate here on latitudinal variability in the forest cover extent and composition of western Europe during the succession of D-O events, showing new pollen records for core MD04-2845 and for marine isotopic stages (MIS) 3 and 4 of core MD99-2331. In general, cold SSTs characteristic of Greenland stadials were contemporaneous with the expansion of semi-desert or steppic vegetation while Greenland interstadials were synchronous with the expansion of forest. Our data reveal that the amplitude of Atlantic and Mediterranean forest expansions differs for any given D-O warming during the glacial period (74-18 ka). In the western Mediterranean, D-O 16-17 and D-O 8 and 7 (corresponding to minima in precession) were associated with strong expansion of forest cover contrasting with weak expansion of forest cover during D-O 14 and 12; the opposite pattern is revealed at the Atlantic sites. Further north, the strongest Greenland warmings are recorded for D-O 19, 11 and 8. This contrasting latitudinal climatic scenario is compared with other northern hemisphere records, revealing similarities between the Mediterranean climate and the Asian monsoon regime, which may relate to a summer atmospheric teleconnection between the two regions comparable to the present-day situation. Parallels between Mediterranean climate enhancement and peaks in global methane (CH4) during the last glacial period suggest a significant role of monsoon activity in determining CH4 emission from wetlands.采自IMAGES深海岩芯MD95-2042、SU81-18（37°N，10°W）、MD99-2331、MD03-2697（42°N，9°W）以及MD04-2845（45°N，5°W）的陆地与海洋代用指标（包括孢粉、浮游及底栖有孔虫氧同位素、烯酮类与有孔虫衍生海表温度（SST）、冰筏碎屑）显示，西欧及近岸海域环境深受丹斯果-奥什格尔（Dansgaard-Oeschger，D-O）事件与赫里希（Heinrich，H）事件的强烈影响。本研究聚焦于D-O事件旋回期西欧森林覆盖范围与组成的纬度变化特征，首次公布岩芯MD04-2845以及岩芯MD99-2331的海洋同位素阶段（MIS）3和4的全新孢粉记录。总体而言，格陵兰冰期阶特征性的低温海表温度，与半荒漠或草原植被的扩张同步；而格陵兰间冰期阶则与森林扩张相伴随。我们的数据揭示，冰期（74~18 ka）内任意一次D-O升温事件中，大西洋与地中海区域的森林扩张幅度存在差异。在西地中海区域，D-O 16-17、D-O 8和7（对应岁差极小值）时期伴随森林覆盖的显著扩张，而D-O 14和12时期森林扩张幅度较弱；大西洋海域站点则呈现相反的变化模式。更北的区域中，格陵兰最显著的升温事件对应D-O 19、11和8。这种差异化的纬度气候格局与其他北半球记录进行对比后发现，地中海气候与亚洲季风系统存在相似性，这可能与两个区域间类似现代的夏季大气遥相关有关。冰期内地中海气候增强与全球甲烷（CH4）峰值的对应关系，表明季风活动在决定湿地甲烷排放方面发挥了重要作用。