Extreme heat and drought have amplified the adverse effects of dust events across Eurasia

Dust aerosols are critical in global climate change and air quality. In the context of global warming, dust emissions are projected to increase in certain dry areas. Utilizing a 40-year dataset of dust records and reanalysis data, along with satellite aerosol products, this study investigates the driving effects of extreme weather conditions on dust emissions and the magnification of their adverse impacts across Eurasia. Analysis reveals an overall upward trend (averaging 0.9 days decade⁻¹) in dust event frequency in Central East Asia over the past four decades, and a rapid increase (averaging 0.28 days yr⁻¹) in dust event occurrences in Mongolia. The study elucidates the influence of key meteorological factors—such as high temperatures, strong winds, low precipitation levels, reduced soil moisture, and diminished NDVI index—on the frequency of dust events across various regions. Particularly, temperature is identified as the dominant driver of the abrupt escalation in dust frequency observed in Middle East (R=0.30), Mongolia between 1994 and 2003 (R=0.62), and northern China (R=0.51). The analysis further indicates a substantial rise of dust events associated with extreme high temperatures accompanied by droughts over the past 40 years. It was also observed that the meteorological conditions, downwind air pollutants, and aerosol optical depth anomalies for dust events compounded by extreme high temperatures and droughts were considerably higher than those for typical dust events. Generalized additive machine learning models was employed to validate the driving impact of extreme weather on Eurasian dust events and the exacerbation of their adverse effects. These findings underscore that the increasing frequency of extreme weather events due to climate warming significantly amplifies the climate impacts and health risks posed by dust aerosols.粉尘气溶胶对全球气候变化和空气质量至关重要。在全球变暖的背景下，预计某些干旱地区的粉尘排放量将增加。利用40年的沙尘记录和再分析数据集，以及卫星气溶胶产品，本研究调查了极端天气条件对欧亚大陆沙尘排放的驱动作用及其不利影响的放大。分析表明，近40年来，中亚地区沙尘事件频次总体呈上升趋势（平均0.9 d /年 ⁻¹ ），蒙古地区沙尘事件频次快速增加（平均0.28 d /年 ⁻¹ ）。研究阐明了高温、强风、低降水、土壤水分减少、NDVI指数降低等关键气象因素对不同区域沙尘事件发生频率的影响。特别是，温度被认为是中东（R=0.30）、蒙古（R=0.62）和中国北方（R=0.51）沙尘频率急剧上升的主要驱动因素。分析进一步表明，在过去40年里，与极端高温和干旱相关的沙尘事件大幅增加。在极端高温和干旱条件下，沙尘事件的气象条件、顺风空气污染物和气溶胶光学深度异常明显高于典型沙尘事件。采用广义加性机器学习模型验证了极端天气对欧亚沙尘事件的驱动作用及其不利影响的加剧。这些发现强调，气候变暖导致的极端天气事件日益频繁，大大放大了沙尘气溶胶造成的气候影响和健康风险。