Impact of millennial-scale fluctuations of the Siberian High on Holocene aeolian activity: Insights from Lake Ailike in arid Central Asia

Abstract

Arid Central Asia (ACA) is a major dust source region in the Northern Hemisphere, owing to the prevalence of aeolian activity that substantially impacts the ecological environment and human wellbeing in this region. However, the driving mechanisms of aeolian activity in ACA during the Holocene are unclear, making it difficult to predict possible future aeolian activity. We used AMS 14C dating, combined with grain-size analysis, high-resolution X-ray fluorescence scanning, and scanning electron microscopy of a sediment core from Lake Ailike, in the Junggar Basin, to reconstruct the history of aeolian activity in ACA during the Holocene. We found that periods of increased aeolian activity on the millennial-scale are correlated with the strengthening of the Siberian High, and that there is a consistency between aeolian activity and climatic fluctuations in the mid-latitudes of Europe. These findings support a close relationship between climate fluctuations in mid- and high-latitude regions of the Northern Hemisphere. Lower/higher temperatures in high latitudes result in the expansion/contraction of polar air masses, leading to the strengthening/weakening of the Siberian High. Additionally, more/less frequent aeolian activity in ACA corresponded to cooling/warming trends in the mid-latitudes of Europe during the Holocene. While ongoing global warming may lead to a long-term decrease in aeolian activity in ACA, the weakening of the polar vortex has resulted in more frequent cold waves affecting the mid-latitudes of Eurasia during winter in recent years.