A descriptive study of dust storms and air quality in a semi-arid region of Mexico

Dust storms are a common phenomenon in arid and semi-arid regions of the world. The erosion in the desert, agricultural, urban, and rural areas contributes to atmospheric mineral dust. Low vegetation cover drives intense dust storms in arid regions like northern Mexico and the southwestern USA. The seasonality associated with winter cold fronts from October to June regulates dust storms. The impact of dust storms is considerable, from massive soil deterioration to health problems caused by policies of changing land use from grasslands and forests to rainfed agriculture. This process has increased notably in recent decades. To identify potential dust storm events, we applied the criterion of a threshold wind speed of 9 m/s in all meteorological stations and data from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. The analysis of wind data allowed identifying 245 cases of potential dust storms occurring between 2006 and 2018, but only 15 were chosen to be analyzed by numerical modeling. The WRF-Chem model version 3.6 was applied. Numerical experiments allowed calculating the fraction of PM10 emitted during each simulated event, where the concentration varied from 34 to 350 μg/m 3 . From the CALIPSO profiles, the atmospheric dust from the outputs of the numerical simulations was verified. Extensive distribution of dust revealed high contributions of PM10 that affect the air quality. The analysis of 13 years of wind data yielded 9 extreme wind events each year exceeding the speed threshold for dust removal.