Home > Articles > Published articles > Trends of particulate matter (PM₂.₅) and chemical composition at a regional background site in the Western Mediterranean over the last nine years (2002-2010) |
Date: | 2012 |
Abstract: | The time variability and long term trends of PM₂. ₅ (particulate matter of diameter <2. 5 μm) at various regional background (RB) sites across Europe are studied and interpreted in this work. Data on mean annual levels of PM₂. ₅ measured at Montseny (MSY, North East Spain) and various RB sites in Spain and Europe are evaluated and compared, and subsequently analysed for statistically significant trends. The MSY site registered higher average PM₂. ₅ levels than those measured at a selection of other RB sites across Spain, Portugal, Germany and Scandinavia by percentage compared to the mean of all the stations in these countries, but lower than those measured in Switzerland, Italy and Austria. Reductions in PM₂. ₅ were observed across all stations in Spain and Europe to varying degrees (7-49%). MSY underwent a statistically significant reduction since measurements began, indicating a year-on-year gradual decrease (−3. 7 μgm¯³, calculated from the final year of data compared to the mean). Similar trends were observed in other RB sites across Spain (−1. 9 μgm¯³). Reductions recorded in PM₂. ₅ across Europe were varied, with many experiencing gradual, year-on-year decreases (−1. 8 μgm¯³). These reductions have been attributed to various causes: the introduction and implementation of pollution abatement strategies in EU member states, the effect of the current economic crisis on emissions of PM₂. ₅ and the influence of meteorology observed during the winters of 2009 and 2010. In addition, the North Atlantic Oscillation (NAO), a large scale meteorological phenomenon most prevalent during winter, was observed to influence the frequency of Saharan dust intrusions across the Iberian Peninsula. Chemical composition of PM₂. ₅ at MSY is characterised by high levels of organic matter (OM) and sulphate, followed by crustal material, nitrate and ammonia. Sea Spray and elemental carbon (EC) comprised a minor part of the total PM₂. ₅ mass. Statistical trend analysis was performed on the various chemical components of PM₂. ₅ recorded at MSY to determine which components were accountable for the decrease in PM₂. ₅ concentration. It is shown that OM underwent the largest decrease over the time period with a statistically significant trend (−1. 3 μgm¯³ compared to the mean), followed by sulphate (−0. 8 μgm¯³), ammonium (−0. 5 μgm¯³) and nitrate (−0. 4 μgm¯³). Conversely, sea spray, EC and crustal a material reductions were found to be negligible. |
Grants: | Ministerio de Ciencia e Innovación CGL2008-06294/CLI Ministerio de Ciencia e Innovación CGL2010-19464/CLI European Commission 262254 European Commission 026140 |
Rights: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. |
Language: | Anglès |
Document: | Article ; recerca ; Versió publicada |
Subject: | Western Mediterranean ; Atmospheric pollutants ; Particulate matter ₂.₅ |
Published in: | Atmospheric chemistry and physics, Vol. 12 No. 18 (September 2012) , p. 8341-8357, ISSN 1680-7324 |
17 p, 449.3 KB |