赛里木湖与可鲁克湖长链烯酮数据集（过去12 ka）

通过分析新疆赛里木湖沉积岩芯中12000年以来的长链烯酮，结合此前发表并更新的青海可鲁克湖长链烯酮记录，揭示了全新世以来中国西北陆地温度及水文环境的变化历史。赛里木湖长链烯酮不饱和度温标（UK’37）显示，在全新世夏季温度逐渐下降的整体趋势下，距今约4200-2800年期间出现异常温暖时期，最高升温可达约6℃，可鲁克湖温度记录也显示此阶段内存在异常高值。长链烯酮盐度指标（%C37:4）则指示全新世以来，赛里木湖湖水逐渐变淡，在异常温暖时期湖水偏咸。同样位于西风区的可鲁克湖也展现了暖/干，冷/湿的典型西风区温湿模态。距今4200-2800年期间中国西北地区出现异常暖期，其他地区也在该时段出现气候异常记录，这或许与当时较强的太阳活动以及大规模气候系统重组相关。

By analyzing long-chain alkenones in sediment cores from Lake Sayram, Xinjiang, spanning the past 12,000 years, combined with previously published and updated long-chain alkenone records from Lake Kuhai, Qinghai, this study reconstructs the Holocene changes in terrestrial temperature and hydrological environment in northwest China. The UK'37 index, a temperature proxy based on the unsaturation degree of long-chain alkenones in Lake Sayram, shows that under the overall trend of gradual cooling of Holocene summer temperatures, an abnormally warm period occurred between approximately 4200 and 2800 years ago, with a maximum temperature increase of up to ~6°C. Temperature records from Lake Kuhai also display abnormally high values during this period. The long-chain alkenone salinity proxy (%C37:4) indicates that Lake Sayram's lake water has gradually freshened since the Holocene, and was relatively saline during the abnormally warm period. Lake Kuhai, also located in the westerly-dominated region, exhibits the typical westerly climate mode characterized by warm/dry and cold/wet conditions. The abnormally warm period in northwest China during 4200–2800 years ago coincided with climate anomaly records in other regions, which may be linked to enhanced solar activity and large-scale climatic system reorganization at that time.