A Study on Dust Storm Pollution and Source Identification in Northwestern China

Area of Science:

• Atmospheric Science
• Environmental Science
• Air Quality Research

Background:

• Lanzhou experienced a significant dust storm in April 2023, drawing public attention.
• Dust storms pose substantial risks to regional air quality and public health.

Purpose of the Study:

• To comprehensively analyze the causes, progression, and sources of the April 2023 Lanzhou dust storm.
• To identify key meteorological factors and geographical origins contributing to the event.
• To propose mitigation strategies for future dust storm events.

Main Methods:

• Utilized HYSPLIT model for backward trajectory analysis to determine dust origins.
• Employed FY-2H satellite data for high-resolution dust distribution mapping.
• Analyzed Aerosol Optical Depth (AOD) using MAIAC AOD product and identified source regions via concentration-weighted trajectory (CWT) analysis.

Main Results:

• PM10 was the dominant pollutant, with significantly elevated AOD values in Lanzhou compared to the annual average.
• Key meteorological factors included a high-pressure ridge, diurnal convection, and conditions favoring dust generation (high temperature, low humidity).
• Dust sources were identified in Central Asia, western Mongolia, Xinjiang, and Gansu, with increased nighttime to daytime concentrations due to atmospheric mixing.

Conclusions:

• The study provides critical insights into the dynamics of Lanzhou dust storms, aiding in prediction and management.
• Effective mitigation requires enhanced monitoring, public advisories, vegetation restoration in source regions, and strengthened regional/international cooperation.
• Understanding transboundary dust transport is crucial for sustainable environmental management in Northwestern China.