The impact of regional atmospheric pollutants (i.e. acid substances, dust, haze, ozone, etc.) via long-range transport on local air quality in Taiwan is significant in particular seasons. Through critical scientific evaluation on contribution of long-transported pollution, we can assess the effectiveness of air pollution control policies, and further predict the short-term and mid-range variabilities of regional atmospheric pollutants. In this project, main tasks are to study the short-term climatic variability in East Asia, establish regional atmospheric air quality forecast system, and further assess the impact of regional air pollution on Taiwan’s air quality, as well as to progressively participate international activities for gaining more technologies for elevating our capability on model prediction. Till January 2017, the major achievements of this project are summarized below:  By analyzing meteorological data for East Asia and Taiwan EPA air quality data in 2006-2015, 12 categories of PM2.5 and O3 episodes are identified, including 8 categories primarily due to the leeside effect of Central Mountain Range (CMR), 1 category of long-range transport, and 3 others of accumulation of local pollutants.  According to AGAGE method and cluster analysis of backward trajectories, the background PM2.5 is about 6 micro-gram m^-3 for Wanli air quality station during fall season which is frequently influenced by Chinese haze.  A preliminary version of atmospheric and air quality modeling forecast system has been constructed using WRF and CMAQ models. The model simulation is made daily. Results are further analyzed and illustrated for 3-day forecast.  Project members have participated conferences such as MICS-Asia, AOGS, CMAS for learning the progress of emission inventory of East Asia and development of models. Besides, we have visited Japan National Institute of Environment (NIES) and Japan Agency for Marine-Earth Science and Technology (JAMSTEC) for learning the operational forecast of air quality and seeking for future collaborations.  The process of pre-warning regional pollution transport and events of subsidence of pollutants induced by typhoon circulations has been established by integrating model and subjective forecast. Case study has been demonstrated for EPA’s timely air quality analysis.

Long-range transport, Regional air quality background values, Air quality forecast