The aim of the JRC-Ispra station for atmospheric research (45°49’N, 8°38’E) is to monitor atmospheric parameters (pollutant concentrations and fluxes, atmospheric particle chemical composition, number size distribution and optical properties) to contribute in assessing the impact of European policies on air pollution and climate change. The station has been operated continuously since November 1985, with a gap in gas phase data in 2003 and 2010 due to a breakdown of the data acquisition system and lack of man-power, respectively. The measurements performed in 2010 led to annual average of 21.8 and 18.4 µg m-3 for PM10 and PM2.5, respectively, well below the European annual limit values of 40 µg/m³ (the European directive 1999/30/EC for the year 2005 and onwards) and 25 µg/m³ (European directive 2008/50/EC for the year 2015 and onwards). Carbonaceous species (organic matter plus elemental carbon) are the main constituents of PM2.5 (~57 %, update) followed by (NH4)2SO4 (24 %, update) and NH4NO3 (12 %, update). The data from 2010 confirmed the seasonal variations observed over the previous years, mainly driven by meteorology rather than by changes in emissions, as revealed by the lidar measurements. Aerosol physical and optical properties were also measured in 2010 (update): The average particle number (from 10 nm to 10 µm) was about 7400 cm-3 and the mean geometric diameter was 70 nm. Their hygroscopic growth at 90% RH varies from <1.2 in December to 1.25 – 1.35 (size dependent) in June. The mean (close to dry) aerosol single scattering albedo at  = 550 nm was 0.76, i.e. low compared to the values generally observed in Europe, which means that the cooling effect of aerosols is reduced in our region compared to others. Long-term trends (over > 20 years) show consistent decreases in sulfur concentrations and deposition, PM mass concentration (about -0.9 µg m-3 yr-1), and from 2003 onwards also a slight decease in ozone concentrations too. The decreasing trends in ozone and oxidised/reduced nitrogen species are much less pronounced.

JENSEN Niels;  GRUENING Carsten;  ADAM Mariana;  CAVALLI Fabrizia;  GRASSI Fabrizio;  DELL'ACQUA Alessandro;  MARTINS DOS SANTOS Sebastiao;  SCHEEREN Hubertus;  DOUGLAS Kevin;  ROUX David;  PUTAUD Jean-Philippe; 

2012-02-22

Publication office of the European Union

JRC68181

978-92-79-23099-8 (print),    978-92-79-23100-1,   

1018-5593 (print),    1831-9424 (online),   

EUR 25219 EN,    OP LB-NA-25219-EN-C (print),    OP LB-NA-25219-EN-N (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC68181,   

10.2788/12254 (print),    10.2788/12259 (online),