Analysis of the Severe Dust Process and Its Impact on Air Quality in Northern China

Abstract

Extreme meteorological events can influence air quality. In March 2021, northern China experienced a severe dust event, leading to widespread air quality deterioration. Using reanalysis datasets and station data, we investigate the synoptic weather patterns, dust transport characteristics, and associated impacts on air quality during this event. The results are as follows. (1) The dust event is closely linked to the Mongolian cyclone, providing favorable conditions for dust emission and long-distance transport. (2) The Gobi Desert in Mongolia is the primary source, with dust particles transported from Mongolia to northern China via the northwesterly flow. Dust transport exhibits a complex three-dimensional structure, with the most intense dust transport at approximately 2500 m altitude. (3) The impact of this dust event on air quality was characterized by its remarkable intensity, extensive spatial coverage, and prolonged duration. Additionally, 58.8% of the stations in northern China experienced pollution, 36.3% of them reached severe pollution levels or higher, and 35.9% of the sites experienced more than 12 h of pollution. (4) The visibility at the northern stations near the dust source rapidly decreases due to solid dust particles. In contrast, the southern stations, with higher moisture content, are primarily affected by liquid particles in terms of visibility. After the frontal passage, wet deposition from the precipitation process gradually improves visibility.

Long-Range Transport of a Dust Event and Impact on Marine Chlorophyll-a Concentration in April 2023

“…The 15-19 March 2021 process was the strongest sandstorm event in the past 10 years in China, with 75% of the sandstorms originating from Mongolia on 14 March [29]. This dust process affected an area of more than 2.9 million km 2 [32] in the northern provinces of China, and 36.3% of the monitoring stations in northern China reached a severe or higher pollution level [33]. Therefore, as a source of dust, Mongolia has increased its influence on the occurrence of dust.…”

Aerosol Types and Their Climatology over the Dust Belt Region

“…The primary origins of natural aerosols are the dust belt [7], an extensive region extending from the western coast of North Africa, traversing through the Middle East [8,9], Central and South Asia [10,11], and reaching all the way to China [12,13]. The Sahara, the world's largest dust source, comprises several major dust origins in North Africa, including Tunisia and Northeast Algeria, the coastal region in Western Sahara and Western Mauritania, the Western Flanks of the Ahaggar Mountains, the Libyan Desert, the Bodele Depression, and the Nubian Desert covering parts of Egypt and Sudan [7,14,15].…”