Hydroclimatic variations of arid central Asia (ACA) significantly impact regional ecosystems and human civilizations. Here we present a lake water salinity record of the last 3,000 years from Lake Sayram in the core area of ACA using a new alkenone isomer-based RIK37 index. Our record shows an abrupt decrease in salinity by more than 5‰ since the “early” Little Ice Age (LIA) (about CE 1150), which can be attributed to the combined effect of regional wetting, cooling, and topographic features. Combined with other moisture records in the region, we find two periods of relatively wet conditions during CE 1150–1550 and 1850 to present, which may be linked to Arctic sea ice expansion due to natural variability and, from CE 1950, anthropogenically induced warming. The wet conditions during CE 1206–1260 may have favored the spread of the Mongol Empire across the entire core area of ACA.
Bibliographical noteFunding Information:
This work was supported by the National Natural Science Foundation of China (Nos. 41702187; 41888101), the Fundamental Research Funds for the Central Universities, the Strategic Priority Research Program of Chinese Academy of Sciences (XDB40010300), and the 2nd Tibetan Plateau Scientific Expedition and Research (2019QZKK0101). We thank J. Jing for assistance during sample pretreatment and M. Ran and H. Xie for providing the A/C data in Lake Aibi and δC data of bulk organic matter in Lujiaowan loess. We are also grateful for the comments from two anonymous reviewers that helped to improve the manuscript. 13
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- Group I Isochrysidales
- alkenone isomer
- arid central Asia
- early Little Ice Age