Articles | Volume 9, issue 2
https://doi.org/10.5194/gi-9-397-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gi-9-397-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
13 Oct 2020
Research article |
| 13 Oct 2020
| 13 Oct 2020
CITYZER observation network and data delivery system
Walter Schmidt
Finnish Meteorological Institute, Erik Palménin aukio 1, 00560
Helsinki, Finland
Ari-Matti Harri
Finnish Meteorological Institute, Erik Palménin aukio 1, 00560
Helsinki, Finland
Finnish Meteorological Institute, Erik Palménin aukio 1, 00560
Helsinki, Finland
Harri Hohti
Finnish Meteorological Institute, Erik Palménin aukio 1, 00560
Helsinki, Finland
Lasse Johansson
Finnish Meteorological Institute, Erik Palménin aukio 1, 00560
Helsinki, Finland
Olli Ojanperä
Vaisala Ltd, Vanha Nurmijärventie 21, 01670 Vantaa, Finland
Erkki Viitala
Emtele Ltd, Tampere, Finland
Jarkko Niemi
HSY Helsinki, Ilmalantori 1, 00240 Helsinki, Finland
Jani Turpeinen
Sasken Finland Oy, Vissavedentie 1, 69600 Kaustinen, Finland
Erkka Saukko
Pegasor Ltd, Hatanpään valtatie 34 C, 33100 Tampere, Finland
Topi Rönkkö
Tampere University of Technology, Kalevantie 4, 33100 Tampere,
Finland
Pekka Lahti
Haaga-Helia University of Applied Sciences, Ratapihantie 13, 00520
Helsinki, Finland
Related authors
No articles found.
Teemu Lepistö, Hilkka Timonen, Topi Rönkkö, and Miikka Dal Maso
Atmos. Chem. Phys., 26, 4215–4230, https://doi.org/10.5194/acp-26-4215-2026, https://doi.org/10.5194/acp-26-4215-2026, 2026
Short summary
Short summary
Condensation of vapour molecules onto aerosol particles is a key process regarding aerosol health and climate effects. The condensation sink (CS) estimates the attachment rate of vapour molecules onto existing particles. Here, we explore the concept of size-resolved CS as many of the effects related to condensation are dependent on the size of the existing particles. Our results show clear location-dependent differences in the CS size distributions which may have not been considered before.
Katariina Kylämäki, Milja Jäppi, Leïla Simon, Wojciech Honkisz, Petteri Marjanen, Laura Salo, Teemu Lepistö, Henna Lintusaari, Luis Barreira, Hannu Kuutti, Matti Rissanen, Piotr Bielaczyc, Hilkka Timonen, Päivi Aakko-Saksa, and Topi Rönkkö
EGUsphere, https://doi.org/10.5194/egusphere-2026-224, https://doi.org/10.5194/egusphere-2026-224, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
Short summary
Short summary
Oxidation flow reactors (OFRs) simulate atmospheric aging of e.g. anthropogenic emissions. In this study, we aged exhaust from passenger cars in two OFRs with different designs. On average, the OFRs produced comparable particle size distributions and emission factors. However, there were differences between the OFRs in secondary particle formation depending on the fuel and technology of the car and the differences were mostly explained by OFR design.
Fanni Mylläri, Niina Kuittinen, Minna Aurela, Teemu Lepistö, Paavo Heikkilä, Laura Salo, Lassi Markkula, Panu Karjalainen, Joel Kuula, Sami Harni, Katriina Kyllönen, Satu Similä, Katriina Kirvelä, Joakim Autio, Marko Palonen, Jouni Valtatie, Anna Häyrinen, Hilkka Timonen, and Topi Rönkkö
Aerosol Research, 4, 23–35, https://doi.org/10.5194/ar-4-23-2026, https://doi.org/10.5194/ar-4-23-2026, 2026
Short summary
Short summary
This study examined particle emissions from a large-scale biomass heating plant. Efficient flue gas cleaning, especially with bag-house filters, significantly reduced primary emissions. However, the potential for secondary aerosol formation was found to be 100–1000 times higher than primary emissions, highlighting the need for further research to support air quality and climate goals.
Sami D. Harni, Lasse Johansson, Jarkko V. Niemi, Ville Silvonen, Juan Andrés Casquero-Vera, Anu Kousa, Krista Luoma, Viet Le, David Brus, Konstantinos Doulgeris, Topi Rönkkö, Hanna E. Manninen, Tuukka Petäjä, and Hilkka Timonen
Atmos. Chem. Phys., 25, 18719–18738, https://doi.org/10.5194/acp-25-18719-2025, https://doi.org/10.5194/acp-25-18719-2025, 2025
Short summary
Short summary
A three-month-long measurement campaign was conducted at Espoo, Finland, in spring 2023. The measurement campaign studied the effect of the noise barrier on pollutant concentration gradients on the side of a major highway. The studied pollutants included PM10, PM2.5, lung deposited surface area (LDSA), particle number concentration (PNC), NO2, and black carbon (BC). The noise barrier was found to be effective in reducing, especially the concentration of particulate pollutants.
Kimmo Teinilä, Teemu Lepistö, Jarkko V. Niemi, Harri Portin, Anssi Julkunen, Anu Kousa, Joel Kuula, Hanna E. Manninen, Pasi Aalto, Tuukka Petäjä, Topi Rönkkö, Erkka Saukko, and Hilkka Timonen
EGUsphere, https://doi.org/10.5194/egusphere-2025-5777, https://doi.org/10.5194/egusphere-2025-5777, 2025
Short summary
Short summary
Particle number concentrations were measured with CPCs and AQ Urban sensors at two different urban environments in Helsinki in 2022. The measurement sites were traffic related and background urban sites. The aim of the study was to investigate suitability of using AQ Urban sensors in urban air quality monitoring to obtain particle number concentrations and challenges related to this.
Kimmo Teinilä, Sanna Saarikoski, Henna Lintusaari, Teemu Lepistö, Petteri Marjanen, Minna Aurela, Heidi Hellén, Toni Tykkä, Markus Lampimäki, Janne Lampilahti, Luis Barreira, Timo Mäkelä, Leena Kangas, Juha Hatakka, Sami Harni, Joel Kuula, Jarkko V. Niemi, Harri Portin, Jaakko Yli-Ojanperä, Ville Niemelä, Milja Jäppi, Katrianne Lehtipalo, Joonas Vanhanen, Liisa Pirjola, Hanna E. Manninen, Tuukka Petäjä, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 25, 4907–4928, https://doi.org/10.5194/acp-25-4907-2025, https://doi.org/10.5194/acp-25-4907-2025, 2025
Short summary
Short summary
Physical and chemical properties of particulate matter and concentrations of trace gases were measured in a street canyon in Helsinki, Finland, and an urban background site in January–February 2022 to investigate the effect of wintertime conditions on pollutants. State-of-the-art instruments and a mobile laboratory were used, and the measurement data were analysed further with modelling tools like positive matrix factorization and the Pollution Detection Algorithm.
Hector Navarro-Barboza, Jordi Rovira, Vincenzo Obiso, Andrea Pozzer, Marta Via, Andres Alastuey, Xavier Querol, Noemi Perez, Marjan Savadkoohi, Gang Chen, Jesus Yus-Díez, Matic Ivancic, Martin Rigler, Konstantinos Eleftheriadis, Stergios Vratolis, Olga Zografou, Maria Gini, Benjamin Chazeau, Nicolas Marchand, Andre S. H. Prevot, Kaspar Dallenbach, Mikael Ehn, Krista Luoma, Tuukka Petäjä, Anna Tobler, Jaroslaw Necki, Minna Aurela, Hilkka Timonen, Jarkko Niemi, Olivier Favez, Jean-Eudes Petit, Jean-Philippe Putaud, Christoph Hueglin, Nicolas Pascal, Aurélien Chauvigné, Sébastien Conil, Marco Pandolfi, and Oriol Jorba
Atmos. Chem. Phys., 25, 2667–2694, https://doi.org/10.5194/acp-25-2667-2025, https://doi.org/10.5194/acp-25-2667-2025, 2025
Short summary
Short summary
Brown carbon (BrC) absorbs ultraviolet (UV) and visible light, influencing climate. This study explores BrC's imaginary refractive index (k) using data from 12 European sites. Residential emissions are a major organic aerosol (OA) source in winter, while secondary organic aerosol (SOA) dominates in summer. Source-specific k values were derived, improving model accuracy. The findings highlight BrC's climate impact and emphasize source-specific constraints in atmospheric models.
Maria Hieta, Iina Jaakonaho, Jouni Polkko, Andreas Lorek, Stephen Garland, Jean-Pierre de Vera, Maria Genzer, and Ari-Matti Harri
Geosci. Instrum. Method. Data Syst., 13, 337–351, https://doi.org/10.5194/gi-13-337-2024, https://doi.org/10.5194/gi-13-337-2024, 2024
Short summary
Short summary
This paper describes new humidity measurements performed with the humidity instruments of the MSL, Mars 2020 and ExoMars missions. Special facilities are needed to create Martian conditions, and a measurement campaign was performed at the German Aerospace Center (DLR) to obtain datasets for REMS-H, MEDA HS and METEO-H instruments. The results from the campaign improved the humidity data we receive from MEDA HS/Perseverance and can further improve the existing Martian relative humidity data.
Sami D. Harni, Minna Aurela, Sanna Saarikoski, Jarkko V. Niemi, Harri Portin, Hanna Manninen, Ville Leinonen, Pasi Aalto, Phil K. Hopke, Tuukka Petäjä, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 24, 12143–12160, https://doi.org/10.5194/acp-24-12143-2024, https://doi.org/10.5194/acp-24-12143-2024, 2024
Short summary
Short summary
In this study, particle number size distribution data were used in a novel way in positive matrix factorization analysis to find aerosol source profiles in the area. Measurements were made in Helsinki at a street canyon and urban background sites between February 2015 and June 2019. Five different aerosol sources were identified. These sources underline the significance of traffic-related emissions in urban environments despite recent improvements in emission reduction technologies.
Teemu Lepistö, Henna Lintusaari, Laura Salo, Ville Silvonen, Luis M. F. Barreira, Jussi Hoivala, Lassi Markkula, Jarkko V. Niemi, Jakub Ondracek, Kimmo Teinilä, Hanna E. Manninen, Sanna Saarikoski, Hilkka Timonen, Miikka Dal Maso, and Topi Rönkkö
Aerosol Research, 2, 271–289, https://doi.org/10.5194/ar-2-271-2024, https://doi.org/10.5194/ar-2-271-2024, 2024
Short summary
Short summary
The performances of different particle lung-deposited surface area (LDSAal) measurement methods (Partector, ELPI+, SMPS/DMPS) were compared in ambient conditions. As LDSAal is a health-relevant metric and rather easy to utilise in air quality monitoring, it is crucial to know how the different methods agree, as there are clear differences in their operation. In all, a comparison of different methods can be complicated; still, the methods agree rather well in terms of local pollution (< 400 nm).
Alex Rowell, James Brean, David C. S. Beddows, Tuukka Petäjä, Máté Vörösmarty, Imre Salma, Jarkko V. Niemi, Hanna E. Manninen, Dominik van Pinxteren, Thomas Tuch, Kay Weinhold, Zongbo Shi, and Roy M. Harrison
Atmos. Chem. Phys., 24, 9515–9531, https://doi.org/10.5194/acp-24-9515-2024, https://doi.org/10.5194/acp-24-9515-2024, 2024
Short summary
Short summary
Different sources of airborne particles in the atmospheres of four European cities were distinguished by recognising their particle size distributions using a statistical procedure, positive matrix factorisation. The various sources responded differently to the changes in emissions associated with COVID-19 lockdowns, and the reasons are investigated. While traffic emissions generally decreased, particles formed from reactions of atmospheric gases decreased in some cities but increased in others.
Joonas Leino, Ari-Matti Harri, Mark Paton, Jouni Polkko, Maria Hieta, and Hannu Savijärvi
Ann. Geophys., 42, 331–348, https://doi.org/10.5194/angeo-42-331-2024, https://doi.org/10.5194/angeo-42-331-2024, 2024
Short summary
Short summary
The 1-D column model has been used extensively in studying the Martian atmosphere. In this study, we investigated the sensitivity of the column model to its initialization. The results of the model were compared with Curiosity rover measurements. The initial value of airborne dust and surface temperature had the greatest influence on the temperature prediction, while the initial atmospheric moisture content and the shape of the initial moisture profile modified the humidity prediction the most.
Leena Kangas, Jaakko Kukkonen, Mari Kauhaniemi, Kari Riikonen, Mikhail Sofiev, Anu Kousa, Jarkko V. Niemi, and Ari Karppinen
Atmos. Chem. Phys., 24, 1489–1507, https://doi.org/10.5194/acp-24-1489-2024, https://doi.org/10.5194/acp-24-1489-2024, 2024
Short summary
Short summary
Residential wood combustion is a major source of fine particulate matter. This study has evaluated the contribution of residential wood combustion to fine particle concentrations and its year-to-year and seasonal variation in te Helsinki metropolitan area. The average concentrations attributed to wood combustion in winter were up to 10- or 15-fold compared to summer. Wood combustion caused 12 % to 14 % of annual fine particle concentrations. In winter, the contribution ranged from 16 % to 21 %.
Magdalena Okuljar, Olga Garmash, Miska Olin, Joni Kalliokoski, Hilkka Timonen, Jarkko V. Niemi, Pauli Paasonen, Jenni Kontkanen, Yanjun Zhang, Heidi Hellén, Heino Kuuluvainen, Minna Aurela, Hanna E. Manninen, Mikko Sipilä, Topi Rönkkö, Tuukka Petäjä, Markku Kulmala, Miikka Dal Maso, and Mikael Ehn
Atmos. Chem. Phys., 23, 12965–12983, https://doi.org/10.5194/acp-23-12965-2023, https://doi.org/10.5194/acp-23-12965-2023, 2023
Short summary
Short summary
Highly oxygenated organic molecules (HOMs) form secondary organic aerosol that affects air quality and health. In this study, we demonstrate that in a moderately polluted city with abundant vegetation, the composition of HOMs is largely controlled by the effect of NOx on the biogenic volatile organic compound oxidation. Comparing the results from two nearby stations, we show that HOM composition and formation pathways can change considerably within small distances in urban environments.
Jean-Philippe Putaud, Enrico Pisoni, Alexander Mangold, Christoph Hueglin, Jean Sciare, Michael Pikridas, Chrysanthos Savvides, Jakub Ondracek, Saliou Mbengue, Alfred Wiedensohler, Kay Weinhold, Maik Merkel, Laurent Poulain, Dominik van Pinxteren, Hartmut Herrmann, Andreas Massling, Claus Nordstroem, Andrés Alastuey, Cristina Reche, Noemí Pérez, Sonia Castillo, Mar Sorribas, Jose Antonio Adame, Tuukka Petaja, Katrianne Lehtipalo, Jarkko Niemi, Véronique Riffault, Joel F. de Brito, Augustin Colette, Olivier Favez, Jean-Eudes Petit, Valérie Gros, Maria I. Gini, Stergios Vratolis, Konstantinos Eleftheriadis, Evangelia Diapouli, Hugo Denier van der Gon, Karl Espen Yttri, and Wenche Aas
Atmos. Chem. Phys., 23, 10145–10161, https://doi.org/10.5194/acp-23-10145-2023, https://doi.org/10.5194/acp-23-10145-2023, 2023
Short summary
Short summary
Many European people are still exposed to levels of air pollution that can affect their health. COVID-19 lockdowns in 2020 were used to assess the impact of the reduction in human mobility on air pollution across Europe by comparing measurement data with values that would be expected if no lockdown had occurred. We show that lockdown measures did not lead to consistent decreases in the concentrations of fine particulate matter suspended in the air, and we investigate why.
Sanna Saarikoski, Heidi Hellén, Arnaud P. Praplan, Simon Schallhart, Petri Clusius, Jarkko V. Niemi, Anu Kousa, Toni Tykkä, Rostislav Kouznetsov, Minna Aurela, Laura Salo, Topi Rönkkö, Luis M. F. Barreira, Liisa Pirjola, and Hilkka Timonen
Atmos. Chem. Phys., 23, 2963–2982, https://doi.org/10.5194/acp-23-2963-2023, https://doi.org/10.5194/acp-23-2963-2023, 2023
Short summary
Short summary
This study elucidates properties and sources of volatile organic compounds (VOCs) and organic aerosol (OA) in a traffic environment. Anthropogenic VOCs (aVOCs) were clearly higher than biogenic VOCs (bVOCs), but bVOCs produced a larger portion of oxidation products. OA consisted mostly of oxygenated OA, representing secondary OA (SOA). SOA was partly associated with bVOCs, but it was also related to long-range transport. Primary OA originated mostly from traffic.
Marc Guevara, Hervé Petetin, Oriol Jorba, Hugo Denier van der Gon, Jeroen Kuenen, Ingrid Super, Jukka-Pekka Jalkanen, Elisa Majamäki, Lasse Johansson, Vincent-Henri Peuch, and Carlos Pérez García-Pando
Earth Syst. Sci. Data, 14, 2521–2552, https://doi.org/10.5194/essd-14-2521-2022, https://doi.org/10.5194/essd-14-2521-2022, 2022
Short summary
Short summary
To control the spread of the COVID-19 disease, European governments implemented mobility restriction measures that resulted in an unprecedented drop in anthropogenic emissions. This work presents a dataset of emission adjustment factors that allows quantifying changes in 2020 European primary emissions per country and pollutant sector at the daily scale. The resulting dataset can be used as input in modelling studies aiming at quantifying the impact of COVID-19 on air quality levels.
Joel Kuula, Hilkka Timonen, Jarkko V. Niemi, Hanna E. Manninen, Topi Rönkkö, Tareq Hussein, Pak Lun Fung, Sasu Tarkoma, Mikko Laakso, Erkka Saukko, Aino Ovaska, Markku Kulmala, Ari Karppinen, Lasse Johansson, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 4801–4808, https://doi.org/10.5194/acp-22-4801-2022, https://doi.org/10.5194/acp-22-4801-2022, 2022
Short summary
Short summary
Modern and up-to-date policies and air quality management strategies are instrumental in tackling global air pollution. As the European Union is preparing to revise Ambient Air Quality Directive 2008/50/EC, this paper initiates discussion on selected features of the directive that we believe would benefit from a reassessment. The scientific community has the most recent and deepest understanding of air pollution; thus, its contribution is essential.
Pak Lun Fung, Martha A. Zaidan, Jarkko V. Niemi, Erkka Saukko, Hilkka Timonen, Anu Kousa, Joel Kuula, Topi Rönkkö, Ari Karppinen, Sasu Tarkoma, Markku Kulmala, Tuukka Petäjä, and Tareq Hussein
Atmos. Chem. Phys., 22, 1861–1882, https://doi.org/10.5194/acp-22-1861-2022, https://doi.org/10.5194/acp-22-1861-2022, 2022
Short summary
Short summary
We developed an input-adaptive mixed-effects model, which was automatised to select the best combination of input variables, including up to three fixed effect variables and three time indictors as random effect variables. We tested the model to estimate lung-deposited surface area (LDSA), which correlates well with human health. The results show the inclusion of time indicators improved the sensitivity and the accuracy of the model so that it could serve as a network of virtual sensors.
Miska Olin, David Patoulias, Heino Kuuluvainen, Jarkko V. Niemi, Topi Rönkkö, Spyros N. Pandis, Ilona Riipinen, and Miikka Dal Maso
Atmos. Chem. Phys., 22, 1131–1148, https://doi.org/10.5194/acp-22-1131-2022, https://doi.org/10.5194/acp-22-1131-2022, 2022
Short summary
Short summary
An emission factor particle size distribution was determined from the measurements at an urban traffic site. It was used in updating a pre-existing emission inventory, and regional modeling was performed after the update. Emission inventories typically underestimate nanoparticle emissions due to challenges in determining them with high certainty. This update reveals that the simulated aerosol levels have previously been underestimated especially for urban areas and for sub-50 nm particles.
Sanna Saarikoski, Jarkko V. Niemi, Minna Aurela, Liisa Pirjola, Anu Kousa, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 21, 14851–14869, https://doi.org/10.5194/acp-21-14851-2021, https://doi.org/10.5194/acp-21-14851-2021, 2021
Short summary
Short summary
This study presents the main sources of black carbon (BC) at two urban environments. The largest fraction of BC originated from biomass burning at the residential site (38 %) and from vehicular emissions (57 %) in the street canyon. Also, a significant fraction of BC was associated with urban background or long-range transport. The data are needed by modelers and authorities when assessing climate and air quality impact of BC as well as directing the emission legislation and mitigation actions.
Dimitrios Bousiotis, Francis D. Pope, David C. S. Beddows, Manuel Dall'Osto, Andreas Massling, Jakob Klenø Nøjgaard, Claus Nordstrøm, Jarkko V. Niemi, Harri Portin, Tuukka Petäjä, Noemi Perez, Andrés Alastuey, Xavier Querol, Giorgos Kouvarakis, Nikos Mihalopoulos, Stergios Vratolis, Konstantinos Eleftheriadis, Alfred Wiedensohler, Kay Weinhold, Maik Merkel, Thomas Tuch, and Roy M. Harrison
Atmos. Chem. Phys., 21, 11905–11925, https://doi.org/10.5194/acp-21-11905-2021, https://doi.org/10.5194/acp-21-11905-2021, 2021
Short summary
Short summary
Formation of new particles is a key process in the atmosphere. New particle formation events arising from nucleation of gaseous precursors have been analysed in extensive datasets from 13 sites in five European countries in terms of frequency, nucleation rate, and particle growth rate, with several common features and many differences identified. Although nucleation frequencies are lower at roadside sites, nucleation rates and particle growth rates are typically higher.
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
Atmos. Chem. Phys., 21, 9931–9953, https://doi.org/10.5194/acp-21-9931-2021, https://doi.org/10.5194/acp-21-9931-2021, 2021
Short summary
Short summary
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.
Jukka-Pekka Jalkanen, Lasse Johansson, Magda Wilewska-Bien, Lena Granhag, Erik Ytreberg, K. Martin Eriksson, Daniel Yngsell, Ida-Maja Hassellöv, Kerstin Magnusson, Urmas Raudsepp, Ilja Maljutenko, Hulda Winnes, and Jana Moldanova
Ocean Sci., 17, 699–728, https://doi.org/10.5194/os-17-699-2021, https://doi.org/10.5194/os-17-699-2021, 2021
Short summary
Short summary
This modelling study describes a methodology for describing pollutant discharges from ships to the sea. The pilot area used is the Baltic Sea area and discharges of bilge, ballast, sewage, wash water as well as stern tube oil are reported for the year 2012. This work also reports the release of SOx scrubber effluents. This technique may be used by ships to comply with tight sulfur limits inside Emission Control Areas, but it also introduces a new pollutant stream from ships to the sea.
Luis M. F. Barreira, Aku Helin, Minna Aurela, Kimmo Teinilä, Milla Friman, Leena Kangas, Jarkko V. Niemi, Harri Portin, Anu Kousa, Liisa Pirjola, Topi Rönkkö, Sanna Saarikoski, and Hilkka Timonen
Atmos. Chem. Phys., 21, 6297–6314, https://doi.org/10.5194/acp-21-6297-2021, https://doi.org/10.5194/acp-21-6297-2021, 2021
Short summary
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 increased knowledge of the variability of PM1 concentration, composition, and sources in a traffic site and the implications for 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.
Cited articles
Business Finland: available at: https://www.businessfinland.fi/en/, last access: 29 January
2020.
Emtele Oy: available at: http://emtele.com, last access: 29 January 2020.
ENFUSER: an air quality forecast software developed at the Finnish
Meteorological Institute in Helsinki, Finland, available at: https://en.ilmatieteenlaitos.fi/environmental-information-fusion-service,
https://en.ilmatieteenlaitos.fi/, last access: 29 January 2020.
Finnish Meteorological Institute: http://data.fmi.fi/, http://en.ilmatieteenlaitos.fi/open-data-manual, last acces: 12 October 2020.
FMI: Finnish Meteorological Institute, available at: https://en.ilmatieteenlaitos.fi/,
last access: 29 January 2020.
GML: ISO 19136:2007 Geographic information – Geography Markup Language,
available at: https://www.iso.org/standard/32554.html, last access: 29 January 2020.
Haaga-Helia University of Applied Sciences: available at: http://www.haaga-helia.fi/en,
last access: 29 January 2020.
Harri, A.-M, Turtiainen, H., Janka, K., Turpeinen, J., Viitala, e.,
Rönkkö, T., Laiho, T., Saari, P., Nousiainen, T., Haukka, H.,
Schmidt, W., and Niemi, J.: CITYZER – Services for effective decision making
and environmental resilience, EGU2018-1924,
https://doi.org/10.13140/RG.2.2.19780.48009, 2018.
HAQT: Helsinki metropolitan Air Quality Testbed, operational service of the
Finnish Meteorological Institute in Helsinki,
available at: http://fmispace.fmi.fi/index.php?id=haqt, last access: 29 January 2020.
Heinonen, M., Jokelainen, M., Fred, T., Koistinen, J., and Hohti J.: Improved
wet weather wastewater influent modelling at Viikinmäki WWTP by on line
weather radar information, Water Sci. Technol., 68, 499–505,
https://doi.org/10.2166/wst.2013.213, 2013
Hietikko, R., Kuuluvainen, H., Harrison, R. M., Portin, H., Timonen, H.,
Niemi, J. V., and Rönkkö, T.: Diurnal variation of nanocluster
aerosol concentrations and emission factors in a street canyon, Atmos.
Environ., 189, 98–106, https://doi.org/10.1016/j.atmosenv.2018.06.031,
2018.
HOPE: Healthy Outdoor Premises for Everyone, an EU-funded air quality
project in Helsinki, Finland, 2019–2021,
available at: https://www.uia-initiative.eu/en/uia-cities/helsinki, last access: 29 January
2020.
HSY: Helsinki Region Environmental Services Authority,
available at: http://www.hsy.fi/en/, last access: 29 January 2020.
INSPIRE: Infrastructure for spatial information in Europe,
available at: https://inspire.ec.europa.eu/, last access: 29 January 2020.
Järvinen, A., Timonen, H., Karjalainen, P., Bloss, M., Simonen, P.,
Saarikoski, S., Kuuluvainen, H., Kalliokoski, J., Dal Maso, M., Niemi, J.V.,
Keskinen, J., and Rönkkö, T.: Particle emissions of Euro VI, EEV and
retrofitted EEV city buses in real traffic, Environ. Pollut., 250,
708–716, https://doi.org/10.1016/j.envpol.2019.04.033, 2019.
HSY Air quality map:
available at: https://www.hsy.fi/en/residents/theairyoubreathe/Pages/airqualitymap.aspx,
last access: 10 March 2020.
Johansson, L., Karppinen, A., and Loven, K.: Evaluation of Air Quality Using
Dynamic Land-use Regression and Fusion of Environmental Information,
Proceedings of the 2nd International Workshop on Environmental Multimedia
Retrieval, ACM New York, NY, USA, 33–38, ISBN: 978-1-4503-3558-4, 2015.
JSON: ISO/IEC 21778:2017 [ISO/IEC 21778:2017] Information technology – The
JSON data interchange syntax, available at: https://www.iso.org/standard/71616.html, last
access: 29 January 2020.
Kuula, J., Kuuluvainen, H., Rönkkö, T., Niemi, J.V., Saukko, E.,
Portin, H., Aurela, M., Saarikoski, S., Rostedt, A., Hillamo, R., and
Timonen, H.: Applicability of Optical and Diffusion Charging-Based
Particulate Matter Sensors to Urban Air Quality Measurements, Aerosol Air Qual. Res., 19, 1024–1039, https://doi.org/10.4209/aaqr.2018.04.0143, 2019.
NetCDF: Network Common Data Format,
available at: https://www.unidata.ucar.edu/software/netcdf/, last access: 29 January
2020.
ODIM Opera Data Information Model for HDF5:
available at: https://www.eumetnet.eu/wp-content/uploads/2019/01/ODIM_H5_ v23.pdf, last access 29 January 2020.
OGC: Open Geospacial Consortium,
available at: http://www.opengeospatial.org/standards/wfs, last access: 29 January 2020.
Pegasor Oy: available at: https://pegasor.fi/, last access: 29 January 2020.
Sasken Finland Oy: available at: https://www.sasken.fi/, last access 29 January 2020
Smart & Clean: The World's Densest Air Quality Measurement System,
available at: http://smartclean.fi/en/projects/the-worlds-densest-air-quality-measurement-system/,
last access: 29 January 2020.
SmartMet: FMI Weather Information and Forecast ProductionSystem,
available at: https://en.ilmatieteenlaitos.fi/documents/30106/486066512/SmartMet_Leaflet.pdf/7c6cfb50-1278-4caf-8840-19b79ca194ab, last access: 29 January
2020.
Tampere University: available at: https://www.tuni.fi/en, last access: 29 January 2020.
Teinilä K., Aurela M., Niemi J., Kousa A., Petäjä T., Järvi
L., Hillamo R., Kangas L., Saarikoski S., and Timonen H.: Concentration
variation of gaseous and particulate pollutants in the Helsinki city centre
– observations from a two-year campaign from 2013–2015, Boreal Env. Res.,
24, 115–136, 2019.
Vaisala Oyj: available at: https://www.vaisala.com/en, last access: 29 January 2020.
Short summary
Combining short-time forecast models, standardized interfaces to a wide range of environment detectors and a flexible user access interface, CITYZER provides decision-making authorities and private citizens with reliable information about the near-future development of critical environmental parameters like air quality and rain. The system can be easily adapted to different areas or different parameters. Alarms for critical situations can be set and used to support authority decisions.
Combining short-time forecast models, standardized interfaces to a wide range of environment...
