Dust storm simulation over the Sahara Desert (Moroccan and Mauritanian regions) using HYSPLIT

Abstract Saharan dust storms are major events that occur normally in the summer and affect the air quality in various regions of the world. In particular, Saharan regions in Morocco and Mauritania actively contribute to dust storms. The Saharan outbreak that took place between 14 and 19 of June 2020 was one of the most severe Saharan dust storms in recent years. This paper investigates the PM10 emissions and concentrations during the 4 days of the dust storm in the region of Western Sahara of Morocco and Mauritania and the transport of the PM10 from the area of study to the Caribbean Sea and the Gulf of Mexico using Hybrid Single‐Particle Lagrangian Integrated Trajectory Model (HYSPLIT) software with PM10 emission model and cluster analysis. We also analyse the effect of the transported PM10 particles on the concentration level in the Southern parts of the United States and the Martinique islands. The results showed that the average PM10 concentration below the altitude of 100 m during the dust storm was higher than 100 μg/m 3 in most of the regions such as Dakhla in Morocco, Nouakchott, Adrar and Tiris Zemmour in Mauritania. This is confirmed by Aerosol Optical Depth (AOD) values between 0.7 and 1 retrieved by MODIS‐Aqua for those areas. Furthermore, PM10 particles transported across the Atlantic Ocean affected the concentrations observed in the Caribbean Basin, where hourly PM10 reached 372 μg/m 3 and the dust top layer was found between 4 and 4.5 km above ground level. In addition, HYSPLIT cluster analysis results revealed several PM10 particle source areas in Western Sahara such as Bir Anzerane in Morocco, Nouakchott and Tichit in Mauritania that contributed to the increase of PM10 concentrations to an Unhealthy level in the Texas and Florida States in the United States.