Frequency analysis of air quality time series for traffic related pollutants
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/8467 |
Resumo: | In the present work, annual time series of traffic related pollutants (CO and PM10) were considered for frequency analysis (Fourier series) with the aim to understand the underlying physical processes and the influence of emission sources on the variability of the air pollutant concentrations. Several urban traffic and suburban background air quality stations located in Porto metropolitan area (Portugal) were analysed. The results obtained for CO and PM10 reveal the important contributions of short-term fluctuations (12 h and 24 h periods). However, the spectrum signals at low frequencies are significantly different between these pollutants thus stressing that temporal variations of CO and PM10 are influenced by different processes. Cross-spectrum analysis of the air quality time series against wind measurements and traffic counts allowed us to identify the contribution of long-range transport over a period of about 21 days to the PM10 fluctuations. Also, a correlation of over 80% between the pollution levels in the vicinity of traffic sources and suburban background levels are found for these harmonic components in the PM10 spectrum, while correlations for CO is below a significant level. Thus, the spectrum and cross-spectrum analysis performed in this study reveal the distinct influence of local traffic emissions and long-range transport to CO and PM10 fluctuations in the polluted urban area. The methodology shows to be a powerful tool for the analysis of the causes of air pollution. |
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Frequency analysis of air quality time series for traffic related pollutantspollutantstrafficPM10In the present work, annual time series of traffic related pollutants (CO and PM10) were considered for frequency analysis (Fourier series) with the aim to understand the underlying physical processes and the influence of emission sources on the variability of the air pollutant concentrations. Several urban traffic and suburban background air quality stations located in Porto metropolitan area (Portugal) were analysed. The results obtained for CO and PM10 reveal the important contributions of short-term fluctuations (12 h and 24 h periods). However, the spectrum signals at low frequencies are significantly different between these pollutants thus stressing that temporal variations of CO and PM10 are influenced by different processes. Cross-spectrum analysis of the air quality time series against wind measurements and traffic counts allowed us to identify the contribution of long-range transport over a period of about 21 days to the PM10 fluctuations. Also, a correlation of over 80% between the pollution levels in the vicinity of traffic sources and suburban background levels are found for these harmonic components in the PM10 spectrum, while correlations for CO is below a significant level. Thus, the spectrum and cross-spectrum analysis performed in this study reveal the distinct influence of local traffic emissions and long-range transport to CO and PM10 fluctuations in the polluted urban area. The methodology shows to be a powerful tool for the analysis of the causes of air pollution.Royal Society of Chemistry2012-05-07T10:56:13Z2010-02-01T00:00:00Z2010-02info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10773/8467eng1464-032510.1039/B913797A10.1039/B913797ATchepel, O.Borrego, C.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T11:11:50Zoai:ria.ua.pt:10773/8467Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T02:44:46.370951Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Frequency analysis of air quality time series for traffic related pollutants |
title |
Frequency analysis of air quality time series for traffic related pollutants |
spellingShingle |
Frequency analysis of air quality time series for traffic related pollutants Tchepel, O. pollutants traffic PM10 |
title_short |
Frequency analysis of air quality time series for traffic related pollutants |
title_full |
Frequency analysis of air quality time series for traffic related pollutants |
title_fullStr |
Frequency analysis of air quality time series for traffic related pollutants |
title_full_unstemmed |
Frequency analysis of air quality time series for traffic related pollutants |
title_sort |
Frequency analysis of air quality time series for traffic related pollutants |
author |
Tchepel, O. |
author_facet |
Tchepel, O. Borrego, C. |
author_role |
author |
author2 |
Borrego, C. |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Tchepel, O. Borrego, C. |
dc.subject.por.fl_str_mv |
pollutants traffic PM10 |
topic |
pollutants traffic PM10 |
description |
In the present work, annual time series of traffic related pollutants (CO and PM10) were considered for frequency analysis (Fourier series) with the aim to understand the underlying physical processes and the influence of emission sources on the variability of the air pollutant concentrations. Several urban traffic and suburban background air quality stations located in Porto metropolitan area (Portugal) were analysed. The results obtained for CO and PM10 reveal the important contributions of short-term fluctuations (12 h and 24 h periods). However, the spectrum signals at low frequencies are significantly different between these pollutants thus stressing that temporal variations of CO and PM10 are influenced by different processes. Cross-spectrum analysis of the air quality time series against wind measurements and traffic counts allowed us to identify the contribution of long-range transport over a period of about 21 days to the PM10 fluctuations. Also, a correlation of over 80% between the pollution levels in the vicinity of traffic sources and suburban background levels are found for these harmonic components in the PM10 spectrum, while correlations for CO is below a significant level. Thus, the spectrum and cross-spectrum analysis performed in this study reveal the distinct influence of local traffic emissions and long-range transport to CO and PM10 fluctuations in the polluted urban area. The methodology shows to be a powerful tool for the analysis of the causes of air pollution. |
publishDate |
2010 |
dc.date.none.fl_str_mv |
2010-02-01T00:00:00Z 2010-02 2012-05-07T10:56:13Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/8467 |
url |
http://hdl.handle.net/10773/8467 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
1464-0325 10.1039/B913797A 10.1039/B913797A |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Royal Society of Chemistry |
publisher.none.fl_str_mv |
Royal Society of Chemistry |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799137499526725632 |