Séminaire
Regional-wide air pollutions of tropospheric O3 and fine particle (PM2.5) are concerned with respect to their health and climate impact in East Asia, experiencing rapid economic growth. Adequate policy measures are necessary to be implemented based on reasonable understanding of physical and chemical processes related to evolution of the pollution events. For this, we have taken a strategy to improve regional chemical-transport models through comparisons with key observations and then to perform sensitivity studies using the improved model systems to assess the effectiveness of the potential measures. From the observations of significant air pollution at the top of Mt. Tai in China in June 2006, we found that open crop residues burning significantly increased concentration levels of O3 and aerosols and implemented the relevant emissions in the model. Potential impact of the co-existing aerosols on reducing ozone formation rates was studied. From observations in Japan since 2009, including those at Fukue Island located in western Japan, we tested the model’s capability to describe O3 and PM2.5 pollution and then estimated that transboundary pollution from China contributed by >50% (or ~12%) for PM2.5 annually (or O3 in spring). We also found that ~20% (or >30%) reductions in emission rates of precursors are necessary to reduce health risks by PM2.5 (or O3), and that emission reductions in the power and industry sectors in China are effective to reduce PM2.5 pollution events.
Juan Cuesta, LISA/IPSL, cuesta@lisa.u-pec.fr