Particulate Pollution in Southeast Asia: Its Impacts on Air Quality and Regional Climate

Particulate pollution has become a serious environmental and societal issue in many Southeast Asian countries in recent decades, threatening human health, interrupting transportation as well as work and outdoor activities, and damaging tourism. By exploiting surface as well as remote sensing observations and state-of-the-science numerical models, we have facilitated studies of the attribution and climatology of these particulate pollutants along with their impacts on regional air quality, weather, and climate in Southeast Asia. The frequent while largely human-initiated biomass burning activities, motivated by various economic reasons, have attracted public attention in causing severe haze or particulate pollution events. However, we find that these smoke aerosols are only responsible for a limited number of pollution events, mostly occurring during the burning seasons. Whereas, for causing the degrading of air quality all year round, aerosols emitted from fossil fuel combustion as well as land use change play a more important role than smoke. In addition, the impacts of particulate pollutants on regional weather and climate have also been identified. These impacts can be implemented through particles’ direct effects on solar radiation and, more effectively, through providing additional cloud condensation nuclei to affect cloud and precipitation formation and development, and eventually river streamflow and hence agriculture in the region.