Holocene dust storms and their driving mechanisms on the northeastern Tibetan Plateau

Abstract

The Tibetan Plateau (TP) is an important dust source region, where frequent dust storms substantially impact the regional ecological environment and even the global climate system. However, the driving mechanisms of dust storms on the northeastern TP during the Holocene are unclear due to the scarcity of geological archives. In this study, a sediment core from Koucha Lake on the northeastern TP was analyzed for grain size, geochemical elements, along with total organic carbon (TOC) and total nitrogen (TN), to infer the Holocene dust storm history and explore the likely driving mechanisms. Our findings indicate that during the late Holocene, especially after 6.9 cal ka BP, dust storm activity intensified with significant fluctuations, reaching a peak after 5 cal ka BP. Notably, our comparison with other climatic environmental records reveals that the pattern of dust storm enhancement during the Holocene diverges from the prevailing trend of increasing moisture availability and vegetation cover, suggesting that these factors may play a limited role in modulating dust storms on the northeastern TP. Instead, the enhancement of dust storms on the northeastern TP during the late Holocene is closely associated with the southward shift of the westerly jet. By revealing dust storm evolution and its mechanisms on the northeastern TP, our study provides a scientific basis for forecasting the future dust storm changes and developing regionally targeted dust mitigation strategies.