TY - JOUR
T1 - In-depth characterization of submicron particulate matter inter-annual variations at a street canyon site in northern Europe
AU - M. F. Barreira, Luis
AU - Helin, Aku
AU - Aurela, Minna
AU - Teinila, Kimmo
AU - Friman, Milla
AU - Kangas, Leena
AU - V. Niemi, Jarkko
AU - Portin, Harri
AU - Kousa, Anu
AU - Pirjola, Liisa
AU - Rönkkö, Topi
AU - Saarikoski, Sanna
AU - Timonen, Hilkka
N1 - Funding Information:
Acknowledgements. We acknowledge funding from the Black Carbon Footprint project funded by Business Finland and participating companies (grant 528/31/2019), from European Regional Development Fund, Urban innovative actions initiative (HOPE; Healthy Outdoor Premises for Everyone, project no. UIA03-240), MegaSense Growth Engine: Air Quality Monitoring funded by Business Finland (grant 7517/31/2018), and ACCC Flagship funded by the Academy of Finland (grant nos. 337552, 337549). We also acknowledge Finland Flagship funding Atmosphere and Climate Competence Center COST–COLOSSAL (CA16109) for the guidance towards high-quality instrument operation and the long-term research co-operation and support from HSY to this project. The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (https://www.ready.noaa.gov, last access: 8 August 2020) used in this publication.
Funding Information:
Financial support. This research has been supported by Busi-
Funding Information:
ness Finland and participating companies (grant no. 528/31/2019), the European Regional Development Fund, Urban innovative actions initiative (grant no. UIA03-240), Business Finland (grant no. 7517/31/2018), and the ACCC Flagship funded by the Academy of Finland (grant nos. 337552 and 337549).
Publisher Copyright:
© 2021 EDP Sciences. All rights reserved.
PY - 2021/4/26
Y1 - 2021/4/26
N2 - Atmospheric aerosols play an important role in air pollution. Aerosol particle chemical composition is highly variable depending on the season, hour of the day, day of the week, meteorology, and location of the measurement site. Long measurement periods and highly time-resolved data are required in order to achieve a statistically relevant amount of data for assessing those variations and evaluating 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 4.5 years (2015-2019) and involved highly time-resolved measurements by taking advantage of a suite of online stateof-the-art instruments such as an aerosol chemical speciation monitor (ACSM), a multi-angle absorption photometer (MAAP), a differential mobility particle sizer (DMPS), and an Aethalometer (AE). PM1 consisted mostly of organics, with mean mass concentrations of 2.89 3 (53% ofPM1) followed by inorganic species (1.56 3, 29 %) and equivalent black carbon (eBC, 0.97 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 (SOAs) during summer and the dominance of ultrafine traffic aerosols during winter. The seasonality of measured constituents also impacted the 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 increased knowledge of 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 illustrative of probable future air quality challenges in countries currently adopting similar environmental regulations..
AB - Atmospheric aerosols play an important role in air pollution. Aerosol particle chemical composition is highly variable depending on the season, hour of the day, day of the week, meteorology, and location of the measurement site. Long measurement periods and highly time-resolved data are required in order to achieve a statistically relevant amount of data for assessing those variations and evaluating 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 4.5 years (2015-2019) and involved highly time-resolved measurements by taking advantage of a suite of online stateof-the-art instruments such as an aerosol chemical speciation monitor (ACSM), a multi-angle absorption photometer (MAAP), a differential mobility particle sizer (DMPS), and an Aethalometer (AE). PM1 consisted mostly of organics, with mean mass concentrations of 2.89 3 (53% ofPM1) followed by inorganic species (1.56 3, 29 %) and equivalent black carbon (eBC, 0.97 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 (SOAs) during summer and the dominance of ultrafine traffic aerosols during winter. The seasonality of measured constituents also impacted the 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 increased knowledge of 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 illustrative of probable future air quality challenges in countries currently adopting similar environmental regulations..
U2 - 10.5194/acp-21-6297-2021
DO - 10.5194/acp-21-6297-2021
M3 - Article
AN - SCOPUS:85104985810
SN - 1680-7316
VL - 21
SP - 6297
EP - 6314
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 8
ER -