Response of extreme precipitation to dust aerosols in the Tarim Basin over the past 50 years

Abstract

Climate warming is simultaneously intensifying both dust activity and extreme precipitation (EP) in the arid and semi-arid regions. Meanwhile, dust aerosols further influence EP through complex cloud physical processes. However, significant uncertainties remain regarding the modulating role of dust aerosols within the aerosol-cloud-precipitation interaction system. There is a pressing need to quantitatively resolve this complex process to address disaster prevention challenges in arid regions. Based on long-term ground-based observations, satellite data, reanalysis data, and the Coupled Model Intercomparison Project Phase 6 (CMIP6) models, this study leverages a systematic analysis to investigate the impact of dust aerosols on EP in the Tarim Basin. Results reveal that dust-related extreme precipitation (D_EP) accounts for a relatively high proportion of EP (35.52 % for frequency and 34.34 % for precipitation amount) in the Tarim Basin. Dust weather provides the necessary lifting for precipitation, while water vapor acts as a limiting factor. Accordingly, dust aerosols enhance precipitation efficiency by increasing cloud particle radius and promoting cloud water path, ice water path, and cloud top height under conditions of sufficient moisture. Furthermore, the regional average contribution of dust aerosols to EP events is quantified as 6.6 % using long-term in situ observations. CMIP6 projections indicate that D_EP events will persist at relatively high values in the near term. These findings reveal that dust aerosols serve as a key regulator of the water cycle in arid regions, providing a new perspective for understanding the mechanisms driving EP.