TY - JOUR
T1 - Measurement report
T2 - The influence of traffic and new particle formation on the size distribution of 1-800nm particles in Helsinki-a street canyon and an urban background station comparison
AU - Okuljar, Magdalena
AU - Kuuluvainen, Heino
AU - Kontkanen, Jenni
AU - Garmash, Olga
AU - Olin, Miska
AU - Niemi, Jarkko V.
AU - Timonen, Hilkka
AU - Kangasluoma, Juha
AU - Tham, Yee Jun
AU - Baalbaki, Rima
AU - Sipilä, Mikko
AU - Salo, Laura
AU - Lintusaari, Henna
AU - Portin, Harri
AU - Teinilä, Kimmo
AU - Aurela, Minna
AU - Dal Maso, Miikka
AU - Rönkkö, Topi
AU - Petäjä, Tuukka
AU - Paasonen, Pauli
N1 - Funding Information:
Financial support. This research has been supported by the
Funding Information:
Acknowledgements. This research was supported by the Regional innovations and experimentations funds AIKO (project HAQT, AIKO014), Business Finland (CITYZER project, Tekes nos. 3021/31/2015 and 2883/31/2015), Pegasor Oy and HSY, Academy of Finland (grant nos. 273010, 307331, 310626, 311932, 316114, 318940, 337549, 1325656, and 326437), Healthy Out-door Premises for Everyone (HOPE), Urban Innovation Actions, Regional development funds, University of Helsinki doctoral programme (ATM-DP) and Faculty of Science 3 year grant (75284132), Tampere University of Technology graduate school (grant no. 326437), and ERA-PLANET project SMURBS (grant agreement 689443) under the EU Horizon 2020 framework.
Funding Information:
the Academy of Finland (grant nos. 273010, 307331, 310626, 311932, 316114, 318940, 1325656, and 326437), the European Commission, Horizon 2020 framework programme (grant no. ERA-PLANET (689443)), the Helsingin Yliopisto (grant no. 75284132), and the Tampereen Teknillinen Yliopisto (grant no. 326437).
Publisher Copyright:
© Copyright:
PY - 2021/7/2
Y1 - 2021/7/2
N2 - Most of the anthropogenic air pollution sources are located in urban environments. The contribution of these sources to the population of atmospheric particles in the urban environment is poorly known. In this study, we investigated the aerosol particle number concentrations in a diameter range from 1 to 800nm at a street canyon site and at a background station within 1km from each other in Helsinki, Finland. We use these number size distribution data together with complementary trace gas data and develop a method to estimate the relative contributions of traffic and atmospheric new particle formation (NPF) to the concentrations of sub-3nm particles. During the daytime, the particle concentrations were higher at the street canyon site than at the background station in all analyzed modes: sub-3nm particles, nucleation mode (3-25nm), Aitken mode (25-100nm), and accumulation mode (100-800nm). The population of sub-3nm and nucleation mode particles was linked to local sources such as traffic, while the accumulation mode particles were more related to non-local sources. Aitken mode particles were dominated by local sources at the street canyon site, while at the background station they were mainly influenced by non-local sources. The results of this study support earlier research showing direct emissions of the sub-3nm particles from traffic. However, by using our new method, we show that, during NPF events, traffic contribution to the total sub-3nm particle concentration can be small and during daytime (6:00-20:00) in spring it does not dominate the sub-3nm particle population at either of the researched sites. In the future, the contribution of traffic to particle number concentrations in different urban environments can be estimated with a similar approach, but determining the relationships between the gas and particle concentrations from observations needs to be conducted with longer data sets from different urban environments.
AB - Most of the anthropogenic air pollution sources are located in urban environments. The contribution of these sources to the population of atmospheric particles in the urban environment is poorly known. In this study, we investigated the aerosol particle number concentrations in a diameter range from 1 to 800nm at a street canyon site and at a background station within 1km from each other in Helsinki, Finland. We use these number size distribution data together with complementary trace gas data and develop a method to estimate the relative contributions of traffic and atmospheric new particle formation (NPF) to the concentrations of sub-3nm particles. During the daytime, the particle concentrations were higher at the street canyon site than at the background station in all analyzed modes: sub-3nm particles, nucleation mode (3-25nm), Aitken mode (25-100nm), and accumulation mode (100-800nm). The population of sub-3nm and nucleation mode particles was linked to local sources such as traffic, while the accumulation mode particles were more related to non-local sources. Aitken mode particles were dominated by local sources at the street canyon site, while at the background station they were mainly influenced by non-local sources. The results of this study support earlier research showing direct emissions of the sub-3nm particles from traffic. However, by using our new method, we show that, during NPF events, traffic contribution to the total sub-3nm particle concentration can be small and during daytime (6:00-20:00) in spring it does not dominate the sub-3nm particle population at either of the researched sites. In the future, the contribution of traffic to particle number concentrations in different urban environments can be estimated with a similar approach, but determining the relationships between the gas and particle concentrations from observations needs to be conducted with longer data sets from different urban environments.
U2 - 10.5194/acp-21-9931-2021
DO - 10.5194/acp-21-9931-2021
M3 - Article
AN - SCOPUS:85109190604
SN - 1680-7316
VL - 21
SP - 9931
EP - 9953
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 13
ER -
