Modal Structure of the Fine Urban Aerosol in four European Cities

The size distribution of the sub micrometer aerosol number concentration in the urban Environment appears to display a statistically significant modal structure (Van Dingenen et al., 2004). This depends on a number of factors such as local atmospheric conditions, density and type of emissions. The development of certain "universal" aerosol number distribution patterns can contribute towards the assessment of human exposure to fine particulate matter or facilitate the characterization of certain emission sources and their impact on air quality. Here, preliminary results from the analysis of measured number size distributions are presented for four European cities.JRC.H.4-Transport and air qualit