Application of multiple wind-roses to improve the modelling of ground-level ozone in the UK

The Edinburgh Lancaster Model for Ozone (ELMO) has been previously used to predict ground-level ozone concentrations in the UK. Here we make significant improvements to its modelling performance by the application of more representative meteorology. We find that when ELMO is used with a series of distance weighted (DW) wind-roses, distributed across the whole of the UK, it closely predicts the 98th percentile of the annual hourly ozone concentration typical of summertime ozone episodes as validated against observations at 15 rural monitoring sites. There is, however, still some over-prediction of this metric in urban and sub-urban areas impacted by large emissions of NOx. We use ELMO with DW wind-roses to predict the effects of reductions of precursor emissions on ozone concentrations and demonstrate the extent to which the UK Air Quality Standard (AQS) for ozone is likely to be exceeded across the country in 2010.