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

重建前几次间冰期的气候变异性，以及准确确定它们的时间和持续时间，提供了关于我们气候系统的重要信息。海洋同位素第9阶段(34万-28万年BP)是一个特别重要的间冰期，因为它显示了过去80万年来工业化前大气中二氧化碳和甲烷的最高浓度。在原始项目的框架内，我们准确地测定了来自德国西部德兴洞穴的五个石笋的年代。由于德辰洞位于冰川时代的永久冻土区，洞穴内洞穴内的洞穴生长对更温暖、更潮湿的气候条件非常敏感。因此，通过对洞穴组的生长阶段进行精确的测年，能够准确地确定MIS9及其子阶段的时间和持续时间。此外，我们生成高分辨率的δ13C和δ18O值以及微量元素记录，这将导致一个完全覆盖MIS9的重复的、精确日期的多代理记录。不幸的是，由于几个原因(清洁实验室中的施工工作、新安装的MC-ICPM的几个问题，特别是全球新冠肺炎大流行)，最初的项目被严重延误。因此，原提案中概述的分析无法按预期进行，因此至少推迟了一年。因此，无法在预定的时间框架内完成对洞穴问题的年代测定和替代分析，而且迄今不可能根据过去的气候变化对数据集进行解释。

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.