Surface ozone measurements at urban coastal site Chennai, in India

The present study was carried out to gain knowledge of current surface ozone concentrations and the effects of meteorological parameters in the highly populated urban area of Chennai, in South India. We have reported measurement results of surface ozone (O3) and meteorological parameters from 17th March to 10th October 2005. A photometric ozone analyzer continuously recorded the ozone concentrations at this site. The present study deals with the statistical characteristics of daily and monthly mean ozone levels under different meteorological conditions. The highest ozone concentrations were recorded in ESE-SE sectors. The monthly mean concentrations were higher in May (23 ± 14 ppb) and lower in April at this site (10 ± 8 ppb). The maximum hourly ozone concentration reached 69 ppb on 21st April.