CORRELATIONS BETWEEN CO, NOY, O-3, AND NONMETHANE HYDROCARBONS AND THEIR RELATIONSHIPS WITH METEOROLOGY DURING WINTER 1993 ON THE NORTH NORFOLK COAST, UK

Measurements of carbon monoxide and other pollutants were performed in a study of polluted air masses during winter at a time when atmospher ic reactivity is low. Data collected during the Weybourne atmospheric observatory winter experiment in 1993 on the North Norfolk Coast, U.K. showed that CO is correlated with other atmospheric species and these correlations are influenced by both chemical and dynamical processes in the lower troposphere. A high pollution event occurred at the begin ning of the campaign with freshly polluted air masses high in CO and n itrogen oxides coming from continental Europe via London. Very low con centrations were experienced towards the end of the period when mariti me Atlantic air was reaching the site. CO showed strong positive corre lation with NOy and non-methane hydrocarbons (NMHCs) as a result of co mmon sources. Correlations between CO and ozone were strong and consis tently negative due to titration of ozone by NO. CO in the background atmosphere in winter was estimated to be 122 ppbv, at a corresponding O-3 concentration of 33 ppbv. Detailed analysis of the pollution event revealed that the polluted airmass originated in London some 9 h befo re reaching Weybourne. Differential decomposition of specific hydrocar bons en route is indicative of daytime hydroxyl radical concentrations of the order of 3 x 10(5) cm(-3). (C) 1998 Elsevier Science Ltd. All rights reserved.