Potassium measurements and ages of sediment cores GeoB5546-2 and GeoB6007-2

The northward extent of the influence of the W African monsoon during humid periods of interglacials is subject to investigations highlighting feedback mechanisms, such as vegetation. To detect this regional variation and the climate system acting farther to the north will be the aim of this paper focussing on the Holocene. We present two very high-resolution Holocene sediment records off NW Africa located at 31°N and 27°N. The well-known mid-Holocene climate change from the "African Humid Period" to present arid conditions is well reflected by the terrigenous input in the southern core. In contrast, in the northern core spectral and wavelet analyses indicate a periodic oscillation of about 900 years of the terrigenous input throughout the last 9000 years B.P. We conclude that the W African monsoonal influence characterized by the abrupt climatic change at 5000 years B.P. can be separated from the influence of the N Atlantic climate system reflected by a periodic oscillation throughout the Holocene.间冰期湿润阶段西非季风影响的北界范围，是当前诸多旨在揭示植被等反馈机制的研究关注议题。本文以全新世（Holocene）为研究对象，旨在揭示这一区域气候变异及更北侧的气候系统活动特征。我们获取了西非近海两处全新世超高分辨率沉积岩芯记录，站位分别位于31°N与27°N。南部岩芯的陆源输入组分清晰记录了广为人知的全新世中期气候转变——从“非洲湿润期（African Humid Period）”过渡至现今的干旱环境。与之形成鲜明对比的是，对北部岩芯开展的频谱分析与小波分析结果显示，在距今9000年以来的时段内，陆源输入组分存在约900年的周期性振荡。综上，我们认为：以距今5000年气候突变为特征的西非季风影响，与全新世以来以周期性振荡为表征的北大西洋气候系统影响，二者可被明确区分。