Abstract

Ozone is an important air pollutant, harmful to human health, agricultural crops and vegetation; the main precursor to the atmospheric oxidants which initiate the degradation of most reactive gases emitted to the atmosphere, and is an important greenhouse gas in its own right. The capacity to understand, predict and so to manage tropospheric ozone levels is a key goal for atmospheric science research. This goal is hard to achieve, as ozone is a secondary pollutant, formed in the atmosphere from the complex oxidation of VOCs in the presence of NOx and sunlight, and a combination of in situ chemical processes, deposition and transport govern ozone levels. Uncertainties in all of these factors affect the accuracy of numerical models used to predict current and future ozone levels. This talk presents results from two complementary experimental approaches (large atmospheric simulation chambers, and field process studies) which aim to provide new understanding of ozone formation in complex atmospheric systems, through an integrated process view : (a) The atmospheric degradation of a new biogenic VOC , Methyl Chavicol, whose emissions are growing exponentially with the expansion of Oil Palm plantations (b) A new approach for the direct measurement of local chemical ozone production rates in the ambient atmospheric boundary layer.