Tan Liangcheng, Cheng Hai, Li Dong, Orozbaev Rustam, Li Yanzhen, Xu Hai, Edwards R Lawrence, Song Yougui, Ma Le, Lin Fangyuan, Sinha Ashish, An Zhisheng
State Key Laboratory of Loess, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China.
Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710054, China.
Proc Natl Acad Sci U S A. 2024 Apr 2;121(14):e2321645121. doi: 10.1073/pnas.2321645121. Epub 2024 Mar 25.
Central Asia (CA) is one of the world's most significant arid regions, which is markedly impacted by global warming. A better understanding of the dynamical processes governing its Holocene climate variability is critical for a better understanding of possible future impacts of climate change in the region. To date, most of the existing CA paleoclimate records are from the summer precipitation-dominated eastern CA (ECA), with few records from the winter precipitation-dominated western CA (WCA). Here, we present a precisely dated (~6‰) and highly resolved (<4-y) record of hydroclimatic variations from the WCA covering the period between 7,774 and 656 y BP. Utilizing multiple proxies (δO, δC, and Sr/Ca) derived from a stalagmite from the Fergana Valley, Kyrgyzstan, we reveal a long-term drying trend in WCA, which is in contrast with the wetting trend in ECA. We propose that different responses of winter and summer westerly jets to seasonal solar insolation over the past 8,000 y may have resulted in an antiphased precipitation relationship between the WCA and ECA. Our data contain dominant quasiperiodicities of 1,400, 50 to 70, and 20 to 30 y, indicating close connections between the WCA climate and the North Atlantic. We further identified a series of droughts and pluvials on centennial-to-decadal timescales, which may have influenced regional societies and trans-Eurasian culture exchanges during historical and prehistorical times.
中亚是世界上最重要的干旱地区之一，受到全球变暖的显著影响。更好地理解控制其全新世气候变化的动力过程，对于更好地理解该地区未来气候变化可能产生的影响至关重要。迄今为止，现有的大多数中亚古气候记录都来自以夏季降水为主的中亚东部（ECA），而来自以冬季降水为主的中亚西部（WCA）的记录很少。在此，我们展示了一份来自WCA的精确测年（约6‰）且高分辨率（<4年）的水文气候变化记录，涵盖了公元前7774年至656年的时间段。利用从吉尔吉斯斯坦费尔干纳谷地的一根石笋中获得的多种代理指标（δO、δC和Sr/Ca），我们揭示了WCA长期的干旱趋势，这与ECA的湿润趋势形成对比。我们认为，过去8000年中冬季和夏季西风急流对季节性太阳辐射的不同响应，可能导致了WCA和ECA之间降水关系的反相位。我们的数据包含1400年、50至70年和20至30年的主导准周期，表明WCA气候与北大西洋之间存在密切联系。我们还确定了一系列百年至十年时间尺度上的干旱和多雨期，这些可能在历史和史前时期影响了区域社会和跨欧亚文化交流。
