Air quality modelling: an investigation of the merits of CMAQ in the analysis of trans-boundary air pollution from continents to small islands

The purpose of this study is to conduct an air quality modelling assessment of trans-boundary air pollutants from the Asian continent by applying an advanced modelling system – the Community Multi-scale Air Quality (CMAQ) – developed by the US Environmental Protection Agency (USEPA). The focus of the study is trans-boundary ozone, Particulate Matter (PM), and acid deposition, using selected episodes of both non-trans-boundary and trans-boundary scenarios in order to provide an understanding of the characteristics of air pollutants for decision- and policy-makers in Taiwan and its islands. The study demonstrates that the Models-3/CMAQ system is capable of simulating key criteria pollutants reasonably well during a typical day, and within an acceptable run time. The CMAQ system has been designed to simulate air quality, as a whole, by including state-of-the-science capabilities for tropospheric ozone, fine particles, toxics, acid deposition and visibility degradation. It provides additional profiles for decision- and policy-makers, and assists the Taiwan Environmental Protection Administration (TEPA) in developing control strategies to improve air quality in the Taiwan Islands. We conclude that the methods used in this paper are readily transferable to most air quality data sets, and that the CMAQ system can be applied to other small islands around the world.