Reconstruction of decadal to orbital-scale climate variability during Marine Isotope Stage 9 using precisely dated multi-proxy speleothem records from Central Europe – Part II

重建以往间冰期的气候变率以及精确确定间冰期的时间和持续时间，为我们的气候系统提供了重要的信息。海洋同位素阶段（MIS） 9 （340,000-280,000 BP）在这一背景下是一个特别重要的间冰期，因为它显示了过去80万年来工业前大气CO2和CH4浓度最高的时期。在原始项目的框架内，我们精确地确定了来自德臣洞穴（德国西部）的五只石笋的年代。由于德辰洞位于冰川时期的永久冻土层，洞穴内的洞穴生长对温暖潮湿的气候条件非常敏感。因此，对洞穴主题生长阶段的精确年代测定可以精确确定MIS 9及其子阶段的时间和持续时间。此外，我们生成了高分辨率的δ13C和δ18O值以及微量元素记录，这将产生一个完全覆盖MIS 9的复制的、精确日期的多代理记录。不幸的是，由于几个原因（清洁实验室的施工工作，新安装的MC-ICPMS的几个问题，特别是全球COVID-19大流行），原项目严重推迟。结果，原提案中概述的分析不能按预期进行，至少推迟了一年。因此，洞穴主题的定年和代理分析都无法在预定的时间框架内完成，而根据过去气候变率对数据集的解释迄今为止是不可能的。

Reconstruction of climate variability during previous interglacials as well as precise determination of their timing and duration provides important information about our climate system. Marine Isotope Stage (MIS) 9 (340,000-280,000 years BP) is a particularly important interglacial in this context because it shows the highest preindustrial atmospheric CO2 and CH4 concentrations of the last 800,000 years.In the framework of the original project, we precisely date five stalagmites from Dechen Cave (western Germany). Since Dechen Cave is located in a region with permafrost during glacial times, speleothem growth within the cave is very sensitive to warmer and wetter climate conditions. Precise dating of the growth phases of the speleothems thus enables precise determination of the timing and duration of MIS 9 and its sub-stages. In addition, we generate high-resolution δ13C and δ18O values as well as trace element records, which will result in a replicated, precisely dated multi-proxy record completely covering MIS 9.Unfortunately, the original project was severely delayed due to several reasons (construction work in the clean laboratory, several problems with the newly installed MC-ICPMS, and in particular the global COVID-19 pandemic). As a result, the analyses outlined in the original proposal could not be conducted as intended and were delayed by at least one year. Therefore, both the dating and the proxy analyses of the speleothems could not be finished in the scheduled time frame, and the interpretation of the dataset in terms of past climate variability has so far been impossible.