| Autor: |
Reche, C.1 cristina.reche@idaea.csic.es, Moreno, T.1, Amato, F.1, Pandolfi, M.1, Pérez, J.2, De La Paz, D.2, Diaz, E.3, Gómez-Moreno, F.J.3, Pujadas, M.3, Artíñano, B.3, Reina, F.4, Orio, A.4, Pallarés, M.4, Escudero, M.5, Tapia, O.5, Crespo, E.6, Vargas, R.6, Alastuey, A.1, Querol, X.1 |
| Předmět: |
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| Zdroj: |
Atmospheric Environment. Jul2018, Vol. 185, p207-220. 14p. |
| Abstrakt: |
Complex spatial and temporal patterns of ground-level O 3 and NO 2 concentrations have been revealed across an important southern European O 3 exceedance area (Madrid Basin, central Spain). Data were obtained from 102 diffusion tube sites and 49 monitoring stations (25 urban/suburban, 12 urban/suburban-traffic, 7 remote, 3 rural, 2 urban-industrial) located through a wide area inside and beyond the city. This new, high-density database confirms that current locations of monitoring stations in the Madrid networks are well positioned to record representative levels of O 3 across the area. Two air quality monitoring stations were identified as reference measurement points, based on their lower O 3 and NO 2 concentrations, and used as a proxy for regional and hemispheric background levels. Although a main regional contribution was evidenced, emissions of local precursors within the Madrid urban plume play a key role in the generation of O 3 exceedances, which are higher and occur earlier near the city than at rural sites, where the effect of NO titration is lower. Despite the fact that weekend emissions of O 3 precursors in Madrid are typically lower than on weekdays, mainly due to fewer road traffic emissions, there is little difference in average values of weekday and weekend O 3 . However, more subtle “weekend effect” differences are revealed by probability density analysis, with high O 3 and low NO 2 at the highest temperature range (30-35° C) at weekends reflecting lower NO titration. This analysis highlights the importance of NO timing with respect to the photochemical activity timing. The complexity of these O 3 pollution patterns in and around the city is dependent on an ever-changing interplay between weather conditions, emission sources, and the timescale required for pollutant transport, chemical processing and recirculation in an evolving contaminated airmass. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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Full Text from ScienceDirect