Meteorological feedback and eco-environmental impact of Asian dust: A simulation study

Abstract

Wind-blown dust plays a crucial role in air quality, biogeochemical cycles, and climate change. In East Asia, one of the main dust source regions in the world, dust storms frequently engulf eastern China, with a substantial negative effect on air pollution and the ecological environment. By integrating multiple observations and the online coupled meteorology-chemistry model WRF-Chem, a severe dust storm event originating from the Gobi Desert in early May 2017 is comprehensively analyzed from the perspective of emission estimation, meteorological feedback, and the possible impact on the ecological environment. We optimize the size distribution of dust aerosol by applying local observations to better represent dust emission and regional transport in the model. Both the observations and simulations indicate that the dust storm broke out with PM10 concentrations exceeding 1500 μg/m3 in the source region of the Gobi Desert, and was quickly transported downwind, deteriorating the air quality of cities in northern and eastern China. Moreover, we find that the dust storm significantly perturbed the temperature stratification, since mineral dust is a radiatively active aerosol and can absorb both short- and long-wave radiation. The upper dust layer at an altitude of around 2–3 km became warmer by 1–2 °C while the surface temperature decreased by about 2 °C, making the planetary boundary layer more stable and indirectly aggravating local air pollution near the ground in eastern China. Furthermore, during this event, a large amount of dust deposition increased ocean primary productivity, with the maximum Chlorophyll-a concentration rising from 4 to 14 mg/m3 in the central area of the Yellow Sea. This study highlights the critical impact of Asian dust pollution on air quality and marine ecosystems in downwind areas.