Al/Si record of sediment core GeoB6211-2@en

Detrending natural and anthropogenic components of climate variability is arguably an issue of utmost importance to society. To accomplish this issue, one must rely on a comprehensive understanding of the natural variability of the climate system on a regional level. Here we explore how different proxies (e.g., stalagmite oxygen isotopic composition, pollen percentages, bulk sediment elemental ratios) record Holocene precipitation variability over southeastern South America. We found a general good agreement between the different records both on orbital and centennial time-scales. Dry mid Holocene, and wet late Holocene, Younger Dryas and a period between ~9.4 and 8.12 cal kyr BP seem to be pervasive features. Moreover, we show that proxy-specific sensitivity can greatly improve past precipitation reconstructions.去除气候变率中的自然与人为组分，无疑是关乎社会发展的核心议题。要攻克这一难题，需建立对区域尺度气候系统自然变率的全面认知。本研究探讨了不同代用指标（proxy）——如石笋氧同位素组成、花粉百分比、全沉积物元素比值——如何记录南美洲东南部的全新世（Holocene）降水变率。研究发现，各类代用记录在轨道尺度与百年尺度上均呈现出总体良好的一致性。全新世中期干旱、全新世晚期湿润、新仙女木事件（Younger Dryas）以及约9.4至8.12校准千年BP（cal kyr BP）之间的时段，均为广泛存在的区域性气候特征。此外，本研究证实，针对代用指标的特异性敏感度分析，可显著优化古降水重建结果。