Home > Articles > Published articles > Volatile organic compounds in the western mediterranean basin : |
Date: | 2013 |
Abstract: | Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, but little is known about the daily VOC mixing ratios in Mediterranean urban and natural environments. We measured VOC mixing ratios concurrently at an urban and a rural site during the winter DAURE campaign in the northeastern Iberian Peninsula, by means of PTR-MS at both locations: a PTR-Quad-MS at the urban site and a PTR-ToF-MS at the rural site. All VOC mixing ratios measured were higher at the urban site (e. g. acetaldehyde, isoprene, benzene, and toluene with averages up to 1. 68, 0. 31, 0. 58 and 2. 71 ppbv, respectively), with the exception of some short-chain oxygenated VOCs such as acetone (with similar averages of 0. 7-1. 6 ppbv at both sites). The average diurnal pattern also differed between the sites. Most of the VOCs at the urban location showed their highest mixing ratios in the morning and evening. These peaks coincided with traffic during rush hour, the main origin of most of the VOCs analyzed. Between these two peaks, the sea breeze transported the urban air inland, thus helping to lower the VOC loading at the urban site. At the rural site, most of the measured VOCs were advected by the midday sea breeze, yielding the highest daily VOC mixing ratios (e. g. acetaldehyde, isoprene, benzene, and toluene with averages up to 0. 65, 0. 07, 0. 19, and 0. 41 ppbv, respectively). Only biogenic monoterpenes showed a clear local origin at this site. In addition, the concentrations of fine particulate matter observed at both sites, together with the synoptic meteorological conditions and radio-sounding data, allowed the identification of different atmospheric scenarios that had a clear influence on the measured VOC mixing ratios. These results highlight thea differences and relationships in VOC mixing ratios between nearby urban and rural areas in Mediterranean regions. Further research in other urban-rural areas is warranted to better understand the urban-rural influence on atmospheric VOC mixing ratios under different atmospheric conditions. |
Grants: | European Commission 215072 Ministerio de Economía y Competitividad CGL2010-17172 Ministerio de Economía y Competitividad CGL2006-04025/BOS Ministerio de Economía y Competitividad FPI-BES-2005-6989 Ministerio de Ciencia e Innovación CSD2008-00040 Ministerio de Ciencia e Innovación CGL2007-30502-E/CLI Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-458 |
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 |
Published in: | Atmospheric chemistry and physics, Vol. 13, issue 8 (April 2013) , p. 4291-4306, ISSN 1680-7324 |
16 p, 5.3 MB |