Modeling the transport of PM10, PM2.5, and O3 from South Asia to the Tibetan Plateau

South Asian air pollutants exert substantial effect on the climate and environment change over the Tibetan Plateau (TP). This paper investigates the trans-boundary transport of PM10, PM2.5, and O-3 from South Asia to the TP via WRF-Chem sensitive analysis. It is found that PM10, PM2.5, and O-3 over South Asia are mainly sourced from anthropogenic sources. South Asian emissions contribute up to 54% of PM10 (PM2.5) in the TP in the premonsoon season. For O-3, the highest contribution of 18.13% is in the monsoon season, while the lowest contribution of 8.67% is in the winter season. To evaluate the respective contributions of anthropogenic and biomass burning emissions in South Asia to PM10, PM2.5, and O-3 in the TP, anthropogenic and biomass burning emissions in South Asia are considered separately. The results show that the largest percentage contribution of PM10 (PM2.5) from South Asian anthropogenic emissions to PM10 (PM2.5) in the TP with value of 35.86% (37.77%) occurs in winter, while the lowest percentage contribution of 16.52% (16.77%) appears in the monsoon season. For O-3, the largest contribution of 17.74% from South Asian anthropogenic emissions appears in the monsoon season, whereas the lowest contribution of 8.59% occurs in winter. Compared to the anthropogenic emissions, the biomass burning emissions in South Asia have a relative less contribution to PM10, PM2.5, and O-3 in the TP. The largest contribution of PM10 (PM2.5) from South Asian biomass burning emissions to PM10 (PM2.5) in the TP is 20.04% (18.37%) in the pre-monsoon season. Conversely, the lowest contribution of 0.58% (0.53) appears in the monsoon season. O-3 from South Asian biomass burning emissions contributes <1% to O-3 in the TP in each season, implying that the biomass burning emissions in South Asia have little effect on O-3 in the TP. This study is of great significance to the ecological environment protection for the TP.