Modal structure of the fine urban aerosol in four European citiesModal structure of the fine urban aerosol in four European cities Περίληψη Δημοσίευσης σε Συνέδριο Conference Paper Abstract 2015-11-142006enThe 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.http://creativecommons.org/licenses/by/4.0/1786-1786International Aerosol Conference Lazaridis Michalis Λαζαριδης Μιχαλης Eleftheriadis, K Vratolis, S Housiadas, C Smolik, J Zdimal, V Schwarz, J Drossinos, Y Hussein, T Kephalopoulos, S Air--Pollution--Control Air contaminants Air pollutants Air pollution Air pollution control Air toxics Airborne pollutants Atmosphere--Pollution Contaminants, Air Control of air pollution Pollutants, Air Toxics, Air air pollution air pollution control air contaminants air pollutants air toxics airborne pollutants atmosphere pollution contaminants air control of air pollution pollutants air toxics air