Holocene dust storm variations across northern monsoonal Asia and arid central Asia: Contrasting impacts of climate change

Abstract

Arid inner Asia, encompassing northern monsoonal Asia (NMA) and arid central Asia (ACA), is the world's second largest dust source region, emitting large quantities of dust particles that travel vast distances around the globe. Previous studies have revealed that the precipitation/moisture variations between NMA and ACA show an out-of-phase or anti-phase relationship on a multi-millennial timescale during the Holocene. However, considering the profound impact of precipitation and related vegetation changes on dust storms, it is unclear whether disparities exist in the variations and mechanisms governing Holocene dust storms between these two regions. Here we use a compilation of Holocene dust storm records from both NMA and ACA, combined with proxy–model comparisons, to demonstrate a consistent temporal pattern of dust storm activity between these regions, with an overall increasing trend on a multi-millennial timescale during the Holocene. Comparison of these dust storm records with regional climate records reveals that surface landscape dominated by the summer monsoon precipitation were the dominant controls on dust storm activity in NMA during the Holocene. In contrast, given the Holocene wetting trend observed for ACA, we propose that precipitation had only a limited influence on modulating the regional dust storms in this region; furthermore, the increasing frequency of dust storms cannot be attributed to decreasing winter monsoon intensity. Instead, we argue that the intensified dust storms in ACA during the late Holocene were triggered by the increased strength and northward (southward) movement of the spring (summer) westerly jet. By revealing the differences in the mechanisms of dust storms across arid inner Asia, our findings provide a scientific basis for implementing policies for dust storm management that can be adapted to meet specific local conditions.