Presently, Central Asia stands as one of the most pronounced arid regions globally. Particularly with the acceleration of global climate change, the region faces daunting challenges such as accelerated glacier melting, shrinking lakes, and water scarcity.
To investigate hydroclimate variations in Central Asia since the mid-Holocene and predict future precipitation trends along with their potential impacts on societal development, the "Extreme Climate Events and Impacts" team (EXCEIS) from the Institute of Earth Environment, Chinese Academy of Sciences, led by Tan Liangcheng, in collaboration with colleagues from both domestic and international institutions, conducted an in-depth study on stalagmite samples collected from the Fergana Basin in Kyrgyzstan. By integrating stalagmite oxygen and carbon isotopes with Sr/Ca ratios, they successfully reconstructed a high-precision (with an error of less than 6‰) and high-resolution (approximately 4 years) hydroclimate record spanning the past 7800 years in Central West Asia.
The findings of this study indicate a gradual drying trend in Central West Asia since the mid-Holocene. Further analysis attributes this trend to decreased summer insolation in the Northern Hemisphere since the mid-Holocene, strengthening and southward shift of the summer westerlies over Central Asia, leading to increased summer precipitation in the eastern part of Central Asia, where summer precipitation predominates. Conversely, in the western part where winter precipitation prevails, the increased winter insolation in the Northern Hemisphere results in a northward shift of the winter westerlies accompanied by temperature rise, reducing Mediterranean storm activity and consequently decreasing moisture transport to Central Asia during winter, resulting in reduced winter precipitation and snow accumulation in the region.
Researchers on a scientific expedition in Central Asia. Photo provided by Tan Liangcheng.
Furthermore, the research findings also indicate that century- to decadal-scale drought events have had profound impacts on the historical societies and even trans-Eurasian cultural exchanges in the region.
The above-mentioned findings were recently published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). Researcher Tan Liangcheng is the first and corresponding author of the article, and Academician An Zhisheng is the co-corresponding author.
Article information: https://doi.org/10.1073/pnas.2321645121
