Mongolian Cyclone Intensification Reshapes Dust Activity in Northwest China

<jats:p>Abstract. Dust storms are a common hazardous weather phenomenon in arid regions. In recent years, dust storm intensity in northwest China has increased markedly under changing atmospheric circulation conditions, yet the underlying mechanisms remain debated. Previous studies have largely attributed dust variability to land-surface changes and broad-scale circulation anomalies, but the spatially divergent responses of different dust source regions to circulation changes remain poorly understood. Here, we investigate Mongolian cyclone variability during 2001–2025 and its impacts on dust activity in the Taklimakan Desert, Alxa Plateau, and Mu Us Sandy Land using multi-source observational data and a random forest regression model. Results showed that (1) Mongolian cyclone intensity increased from 94.84 × 10-5 s-1 to 97.76 × 10-5 s-1 and shifted southward by about 2.08° after 2019; (2) Strengthened Mongolian cyclone activity enhanced dust emissions in the Alxa Plateau (from 0.23 to 0.28 g·m-2 since 2019), whereas dust activity declined in the Taklimakan Desert, which is less affected by Mongolian cyclone forcing (from 0.63 to 0.57 g·m-2 since 2019); (3) Wind was the dominant driver of dust activity (contribution &gt;0.60), while precipitation and the Pressure Gradient Index (PGI) were important secondary contributors in the Alxa and Mu Us regions, and PGI partially modulated wind effects in surrounding cities; and (4) Regional spring mean PM10 concentrations are projected to increase substantially during 2026–2100 (229.98–824.31 μg·m-3) and show weak sensitivity to emission scenarios. These findings highlight the importance of explicitly considering cyclone-wind regime-topography interactions in future dust projections, as circulation-driven variability may play a larger role than previously recognized in regulating East Asian dust activity.</jats:p>