Effect of dispersion normalisation on long-term source apportionment and trends of ultrafine particles in Barcelona (NE Spain)
Ultrafine particles (UFPs, ≤100 nm) are a major component of urban air pollution, influenced by source emission rates (of UFPs and precursors) and meteorological conditions, both of which vary over time. This study evaluates the effect of dispersion normalisation on UFP source apportionment and long...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/412374 |
| Acceso en línea: | http://hdl.handle.net/10261/412374 https://api.elsevier.com/content/abstract/scopus_id/105025476290 |
| Access Level: | acceso abierto |
| Palabra clave: | Ventilation coefficient Air quality Inter-annual variability Particle number size distributions Positive matrix factorisation http://metadata.un.org/sdg/13 http://metadata.un.org/sdg/12 http://metadata.un.org/sdg/9 http://metadata.un.org/sdg/11 http://metadata.un.org/sdg/3 Ensure healthy lives and promote well-being for all at all ages Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation Make cities and human settlements inclusive, safe, resilient and sustainable Ensure sustainable consumption and production patterns Take urgent action to combat climate change and its impacts |
| Sumario: | Ultrafine particles (UFPs, ≤100 nm) are a major component of urban air pollution, influenced by source emission rates (of UFPs and precursors) and meteorological conditions, both of which vary over time. This study evaluates the effect of dispersion normalisation on UFP source apportionment and long-term trends in the urban background of Barcelona (NE Spain) over a 12-year period (2013–2024). Hourly particle number size distributions (PNSD) were normalised using the ventilation coefficient (VC), derived from boundary layer height and wind speed, and analysed with positive matrix factorisation (PMF) for cold (October–March) and warm (April–September) seasons. Seven factors were identified, with road traffic as the dominant contributor. Dispersion corrected (DC) traffic contributions averaged 57 % of particle number concentrations (PNCs), compared with 64 % in the uncorrected (UC) analysis, indicating overestimation of local sources when dispersion is not considered. Photonucleation and Nucleation growth showed higher DC contributions (37 % compared with 31 % for UC), consistent with midday occurrence under favourable mixing conditions. Trend analysis revealed significant decreases in PNCs (−4.4 % yr<sup>−1</sup>), strongest in the Aitken mode, likely linked to reduced traffic emissions following EURO 5/6 regulations, the introduction of diesel particulate filters (DPFs), and the implementation of Barcelona's low emission zone (LEZ). Traffic-related factors declined by −4.6 % yr<sup>−1</sup>, with the largest decrease in the diesel-related source. Nucleation growth and Regional-1 also declined, while Photonucleation and Regional-2 showed no clear trend. These findings highlight the value of dispersion normalisation in source apportionment and provide strong evidence of the effectiveness of emission control-policies in reducing traffic-related UFPs. |
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