Transport, mixing and feedback of dust, biomass burning and anthropogenic pollutants in eastern Asia: a case study

Abstract

Abstract. Anthropogenic fossil fuel (FF) combustion, biomass burning (BB) and desert dust are the main sources of air pollutants around the globe but are particularly intensive and important for air quality in Asia in spring. In this study, we investigate the vertical distribution, transport characteristics, source contribution and meteorological feedback of these aerosols in a unique pollution episode that occurred in eastern Asia based on various measurement data and modeling methods. In this episode, the Yangtze River Delta (YRD) in eastern China experienced persistent air pollution, dramatically changing from secondary fine particulate pollution to dust pollution in late March 2015. The Eulerian and Lagrangian models were conducted to investigate the vertical structure, transport characteristics and mechanisms of the multi-scale, multisource and multiday air pollution episode. The regional polluted continental aerosols mainly accumulated near the surface, mixed with dust aerosol downwash from the upper planetary boundary layer (PBL) and middle–lower troposphere (MLT), and further transported by large-scale cold fronts and warm conveyor belts. BB smoke from Southeast Asia was transported by westerlies around the altitude of 3 km from southern China, was further mixed with dust and FF aerosols in eastern China and experienced long-range transport over the Pacific. These pollutants could all be transported to the YRD region and cause a structure of multilayer pollution there. These pollutants could also cause significant feedback with MLT meteorology and then enhance local anthropogenic pollution. This study highlights the importance of intensive vertical measurement in eastern China and the downwind Pacific Ocean and raises the need for quantitative understanding of environmental and climate impacts of these pollution sources.

Aerosol‐Radiation Interactions of Dust Storm Deteriorate Particle and Ozone Pollution in East China

“…Besides, YRD also suffers from long-range transported mineral dust from inland source regions such as Gobi Desert, which is often mixed with anthropogenic pollutants (X. X. Zhang et al, 2018;Zhou et al, 2018). Such mixing can contribute to the deterioration of air quality in two ways.…”

El Niño–Southern Oscillation (ENSO) effect on interannual variability in spring aerosols over East Asia

“…For instance, the weakening of the East Asia winter monsoon (EAWM) has led to an increase in heavy fog haze over eastern China during recent years (Niu et al, 2010), while the East Asia summer monsoon (EASM) is negatively correlated with aerosol concentrations over eastern China (Zhang et al, 2010a). In addition, the East Asian aerosol variation can be modulated by climate anomalies due to other factors, including the Arctic sea ice (Wang et al, 2015;Zou et al, 2017), Eurasian snowpack (Yin and Wang, 2017), and sea surface temperature (SST) (e.g. Liu et al, 2013;Feng et al, 2016b;Sun et al, 2018).…”

Biomass-burning-induced surface darkening and its impact on regional meteorology in eastern China

“…Eastern China has been characterized by intensive straw burning every June, the harvest season for winter wheat (He et al, 2007;Huang et al, 2012aLi et al, 2016;Yang et al, 2013;Yin et al, 2019). After revolution in rural fuel structure, farmers, who are eager to deal with tons of wheat straw, always resort to burning on site rather than taking it as fuel (Lu et al, 2011;Yan et al, 2006;Zhu et al, 2019). Hence, the wheat straw burning is exceedingly dense in both time and space (Huang et al, 2012b;Yang et al, 2008).…”