|
Document Type |
: |
Article In Journal |
|
Document Title |
: |
Comparison of Temporal Features of Sulphate and Nitrate at Urban and Rural Sites in Spain and the UK مقارنة الخصائص الزمنية للكبريتات والنترات في المواقع الحضرية والريفية في كل من اسبانيا والمملكة المتحدة |
|
Subject |
: |
Enviromental sciences |
|
Document Language |
: |
English |
|
Abstract |
: |
A seasonal comparison of aerosol secondary inorganic component (SIC) patterns on annual, weekly and daily timescales has been performed at urban Madrid and London and at rural sites in the central Iberian Peninsula and south-eastern UK alongside data for precursor gases. A database from winter 2004 to summer 2011 has been analysed. Results show the dominant processes affecting the formation and evolution of nitrate (NO 3 ) and sulphate ðSO2 4 Þ in both regions. In Madrid, photochemistry dominates formation of nitrate, which is mostly locally-generated. Strong thermal decomposition results in very low concentrations in summer. In contrast, in London high nocturnal values suggest the importance of heterogeneous formation processes as well as nitrate condensation at lower temperatures. The seasonal nitrate maximum in the UK is found in late winter-early spring, when the region typically receives the highest input of pollutants transported from mainland Europe. Daily evolution of nitrate in both cities is heavily influenced by meteorological factors. Seasonal sulphate patterns show no obvious trend, except at the Spanish rural site in summer where photochemical formation was apparent. In Madrid, daily SO2 and sulphate patterns exhibiting maximum concentrations at noon were found in winter. In previous studies this phenomenonwas observed for SO2 in London, where itwas explained by the entrainment of pollutants from aloft into the mixing layer. SIC weekend reductions were investigated at the urban background sites of Madrid and London, and in both cities statistically significant fine nitrate reductions of around 20% are found in summer. These values are consistent with the annual reductions observed by researchers in the US.Weekend sulphate reductions occurred in winter, reflecting a clear impact of anthropogenic sulphate in urban environments, in spite of the large reductions in sulphur emissions in Europe in the last decade. Ratios of nitrate and sulphate to oxidant gases and to one another have been calculated forMadrid, and are consistent with a contribution of local formation to sulphate in winter, while in summer a regional background unrelated to urban SO2 is observed. The strong differences in the behaviour seen in London and Madrid (and the rural sites) emphasises the need to study cities individually and not to extrapolate conclusions drawn in one city to others in different climate/topographic situations. |
|
ISSN |
: |
1352-2310 |
|
Journal Name |
: |
Atmospheric Environment |
|
Volume |
: |
60 |
|
Issue Number |
: |
1 |
|
Publishing Year |
: |
1433 AH
2012 AD |
|
Article Type |
: |
Article |
|
Added Date |
: |
Sunday, June 2, 2013 |
|
Researchers
| M.A. Revuelta | Revuelta, M.A. | Researcher | | maranzazu.revuelta@ciemat.es |
| R.M. Harrison | Harrison, R.M. | Researcher | | |
| L. Núñez | Núñez, L. | Researcher | | |
| F.J. Gomez-Moreno | Gomez-Moreno, F.J. | Researcher | | |
| M. Pujadas | Pujadas, M. | Researcher | | |
| B. Artíñano | Artíñano, B. | Researcher | | |
|
Files
|
35589.pdf
| pdf | -Comparison of temporal features of sulphate and nitrate at urban and rural sites in Spain and the UK |
|