1. Regional drought shifts (1710-2010) in East Central Asia and linkages with atmospheric circulation recorded in tree-ring δ18O.
- Author
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Xu, Guobao, Liu, Xiaohong, Trouet, Valerie, Treydte, Kerstin, Wu, Guoju, Chen, Tuo, Sun, Weizhen, An, Wenling, Wang, Wenzhi, Zeng, Xiaomin, and Qin, Dahe
- Subjects
DROUGHTS ,ATMOSPHERIC circulation ,TREE-rings ,MOISTURE ,METEOROLOGICAL precipitation - Abstract
Drought occurrence and duration in central Asia are of important socioeconomic, ecological, and geophysical significance and have received increasing research attention in recent years. Understanding long-term drought trends and their driving forces require reliable records of past drought variability with broad spatial representativeness. Here, we compiled four tree-ring δ
18 O records from eastern central Asia (ECA) and composited them into a drought-sensitive proxy to explore regional ECA moisture variations over the past 301 years (1710-2010 CE). A robust regional standardized precipitation-evapotranspiration index (SPEI) reconstruction was established based on the tree-ring cellulose δ18 O fractionation mechanism and statistically significant proxy-climate relationships. We identified prominent droughts in 1710-1770, 1810-1830, and the beginning of the twenty-first century, and a regime shift to a persistently wet period from the 1880s to 2000. Our reconstruction reveals the impact of drought and pluvial patterns on the decline of Zhungar Empire, and on historical agricultural and socio-economical activities, including increased migration into ECA during the 1770-1800 pluvial. Our findings also suggest that wet conditions in the twentieth century in ECA were related to a strengthening of the westerly circulation and thus shed light on large-scale atmospheric circulation dynamics in central Asia. [ABSTRACT FROM AUTHOR]- Published
- 2019
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