Articles | Volume 23, issue 16
https://doi.org/10.5194/acp-23-9347-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-23-9347-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Aug 2023
Research article |
| 24 Aug 2023
| 24 Aug 2023
Effect of radiation interaction and aerosol processes on ventilation and aerosol concentrations in a real urban neighbourhood in Helsinki
Jani Strömberg
CORRESPONDING AUTHOR
Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki, Finland
Xiaoyu Li
Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki, Finland
Mona Kurppa
Kjeller Vindteknikk, Espoo, Finland
Heino Kuuluvainen
Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
Liisa Pirjola
Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki, Finland
Department of Automotive and Mechanical Engineering, Metropolia University of Applied Sciences, Vantaa, Finland
Leena Järvi
Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki, Finland
Helsinki Institute of Sustainability Science, Faculty of Science, University of Helsinki, Helsinki, Finland
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Magdalena Okuljar, Heino Kuuluvainen, Jenni Kontkanen, Olga Garmash, Miska Olin, Jarkko V. Niemi, Hilkka Timonen, Juha Kangasluoma, Yee Jun Tham, Rima Baalbaki, Mikko Sipilä, Laura Salo, Henna Lintusaari, Harri Portin, Kimmo Teinilä, Minna Aurela, Miikka Dal Maso, Topi Rönkkö, Tuukka Petäjä, and Pauli Paasonen
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To estimate the relative contribution of different sources to the particle population in an urban environment, we conducted simultaneous measurements at a street canyon and an urban background station in Helsinki. We investigated the contribution of traffic and new particle formation to particles with a diameter between 1 and 800 nm. We found that during spring traffic does not dominate the particles smaller than 3 nm at either of the stations.
Mona Kurppa, Pontus Roldin, Jani Strömberg, Anna Balling, Sasu Karttunen, Heino Kuuluvainen, Jarkko V. Niemi, Liisa Pirjola, Topi Rönkkö, Hilkka Timonen, Antti Hellsten, and Leena Järvi
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High-resolution modelling is needed to solve the aerosol concentrations in a complex urban area. Here, the performance of an aerosol module within the PALM model to simulate the detailed horizontal and vertical distribution of aerosol particles is studied. Further, sensitivity to the meteorological and aerosol boundary conditions is assessed using both model and observation data. The horizontal distribution is sensitive to the wind speed and stability, and the vertical to the wind direction.
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Short summary
We conclude that with low wind speeds, solar radiation has a larger decreasing effect (53 %) on pollutant concentrations than aerosol processes (18 %). Additionally, our results showed that with solar radiation included, pollutant concentrations were closer to observations (−13 %) than with only aerosol processes (+98 %). This has implications when planning simulations under calm conditions such as in our case and when deciding whether or not simulations need to include these processes.
We conclude that with low wind speeds, solar radiation has a larger decreasing effect (53 %) on...
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