The Frequency and Intensity of Extreme Dust Events and Related Driving Factors in Major Dust Sources Based on MERRA-2 Aerosol Reanalysis

Abstract Extreme dust events (EDEs) have become intensified in recent years, causing serious environmental issues. Current EDE-related research mainly focused on case studies, leading to a limited understanding of long-term EDE frequency and intensity. Moreover, aerosol reanalysis products are increasingly used in dust-related studies, while their performance on EDEs remains unclear. Accordingly, based on MODIS satellite observations and MERRA-2 aerosol reanalysis, this study analyzes the frequency, intensity, and driving factors of spring EDEs during 2000–23. Due to the regional disparities in assimilation data, the applicability of MERRA-2 has significant regional differences, with favorable performance in the Middle East (ME) and North Africa (NA), while underperforming in the Taklamakan Desert. The EDE frequency increases and then decreases in ME and NA, with higher EDE intensity in NA. Spring EDEs in NA and ME are both driven by the East Atlantic/West Russia teleconnection which can cause anomalous high pressure over the Mediterranean Sea and anomalous low pressure over the Eurasian continent, rather than by the North Atlantic Oscillation. The propagation of the corresponding Rossby wave results in EDEs occurring successively in NA and ME. Furthermore, it should be noted that DOD during EDEs is an independent mode, rather than an extreme feature of spring-averaged DOD. Our study highlights regional differences in the applicability of MERRA-2 and the independence of EDEs as well as indicates that the driving effect of the East Atlantic/West Russia teleconnection on EDEs should be given attention in the prediction of EDEs in NA and ME.