Preprints
https://doi.org/10.5194/acp-2020-908
https://doi.org/10.5194/acp-2020-908

  09 Nov 2020

09 Nov 2020

Review status: a revised version of this preprint is currently under review for the journal ACP.

In-depth characterization of submicron particulate matter inter-annual variations at a street canyon site in Northern Europe

Luis M. F. Barreira1, Aku Helin1, Minna Aurela1, Kimmo Teinilä1, Milla Friman1, Leena Kangas1, Jarkko V. Niemi2, Harri Portin2, Anu Kousa2, Liisa Pirjola3, Topi Rönkkö4, Sanna Saarikoski1, and Hilkka Timonen1 Luis M. F. Barreira et al.
  • 1Atmospheric Composition Research, Finnish Meteorological Institute, Helsinki, FI-00101 Finland
  • 2Helsinki Region Environmental Services Authority, Helsinki, FI-00066 HSY, Helsinki, Finland
  • 3Department of Automotive and Mechanical Engineering, Metropolia University of Applied Sciences, FI-01600 Vantaa, Finland
  • 4Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland

Abstract. Atmospheric aerosols play an important role in air pollution. Aerosol particle's chemical composition is highly variable depending on the season, hour of the day, day of the week, meteorology, and the location of the measurement site. Long measurement periods and high time-resolved data are required in order to achieve statistically relevant amount of data for assessing those variations and evaluate pollution episodes. In this study, we present continuous atmospheric PM1 (particulate matter < 1 µm) concentration and composition measurements at an urban street canyon site located in Helsinki, Finland. The study was performed for four and a half years (2015–2019) and involved highly time-resolved measurements by taking advantage of a suite of online state-of-art instruments such as Aerosol Chemical Speciation Monitor (ACSM), Multi-Angle Absorption Photometer (MAAP), Differential Mobility Particle Sizer (DMPS) and Aethalometer (AE). PM1 consisted mostly of organics, with mean mass concentrations of 2.89 µg m−3 (53 % of PM1) followed by inorganic species (1.56 µg m−3, 29 %) and equivalent black carbon (eBC, 0.97 µg m−3, 18 %). A trend analysis revealed a decrease in BC from fossil fuel (BCFF), organics and nitrate over the studied years. Clear seasonal and/or diurnal variations were found for the measured atmospheric PM1 constituents. Particle number and mass size distributions over different seasons revealed the possible influence of secondary organic aerosols (SOA) during summer and the dominance of ultrafine traffic aerosols during winter. The seasonality of measured constituents impacted also on particle's coating and absorptive properties. The investigation of pollution episodes observed at the site showed that a large fraction of aerosol particle mass was comprised of inorganic species during long-range transport, while during local episodes eBC and organics prevailed together with elevated particle number concentration. Overall, the results enlightened the variability of PM1 concentration and composition in a Nordic traffic site, and its implications on urban air quality. Considering the effects of PM mitigation policies in Northern Europe in the last decades, the results obtained in this study may be considered as illustrative of probable future air quality challenges in countries currently adopting similar environmental regulations.

Luis M. F. Barreira et al.

 
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for authors/editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Luis M. F. Barreira et al.

Luis M. F. Barreira et al.

Viewed

Total article views: 153 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
89 62 2 153 29 6 5
  • HTML: 89
  • PDF: 62
  • XML: 2
  • Total: 153
  • Supplement: 29
  • BibTeX: 6
  • EndNote: 5
Views and downloads (calculated since 09 Nov 2020)
Cumulative views and downloads (calculated since 09 Nov 2020)

Viewed (geographical distribution)

Total article views: 261 (including HTML, PDF, and XML) Thereof 257 with geography defined and 4 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 07 Mar 2021
Download
Short summary
We present results from the long-term measurements (5 years) of highly-time resolved atmospheric PM1 composition at an urban street canyon site. Overall, the results enlightened the variability of PM1 concentration, composition and sources in a traffic site, and its implications on urban air quality. The investigation of pollution episodes showed that both local and long-range transported pollutants can still cause elevated PM1 and PM2.5 concentrations in Northern Europe.
Altmetrics