Examining the Global Impact of Local/regional Air Pollution: the Role of Global Chemical Transport Models

The environmental impact of chemically reactive air pollutants on both local air quality (smog) and the regional ecosystem (acid rain) is well established. The chemical and meteorological models used to study these problems are well known to most at this conference. On a larger scale are the potential impacts of air pollution on the global environment, both direct (air quality, sulfur and nitrogen budgets) and indirect (atmospheric reactivity, climate). Pollution sources of 502, NOx and CO form a major component of the respective global budgets (e.g. Logan et al., 1981; Logan, 1983). Moreover, NOx concentrations, in both the polluted cities and the remote troposphere, play the dominant role in tropospheric ozone production (e.g. Isaksen, 1988), and indirectly control the oxidative power of the troposphere, i.e. its ability to cleanse itself of greenhouse gases such asmethane. Gaseous sulfur levels over the ocean may have a major impact, via CCN levels, on global cloudiness and climate (Charlson et al., 1988).