Air Mass Back Trajectories And Particulate Matter Concentration At A Site On The South Coast Of England
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A. R. Deacon & K. L. Smallbone
Air mass back trajectories and particulate matter concentration at a site on the south coast of England A. R. Deacon & K. L. Smallbone Division of Geography, School of the Environment, The University of Brighton, UK, Abstract Recent concern over the health effects of PM10 (Hajat et al , Greenbaum et al ) combined with the legislative drive towards long-term air quality objectives has led to the need for better understanding of the nature and characteristics of particulate matter (PM) less than 10pm. This study has highlighted a number of issues relating to monitoring PM2.5.and PM10. Monitoring of PM10 and PM2.5 particulate matter was carried out at an urban background site in Eastbourne, East Sussex, UK for nine months between March and December 2001. These data have been analysed alongside on-site meteorological data and atmospheric back trajectories (calculated using the British Atmospheric Data Centre back trajectory system). Overall, PM2.5 represented 69.5% of the PM10 concentration at the site, with marked differences in this proportion between summer and winter months but not between weekdays and weekends. Analysis of back trajectories during periods when PM2.5 contributes more than 85% of PM10 has shown that there were differences between summer and winter events. Under summer anticyclonic conditions, airmasses have travelled shorter distances and are more mixed, whilst winter events show back trajectories arriving at the site from Continental and Eastern Europe. Pollution rose plots for the site also show an increased proportion of PM2.5 when winds are from North- West to North-East and from the South-East to South. Comparison with previous work has highlighted the importance of the regional component of PM2.5 as well as PM10.