34 results on '"Neitola, Kimmo"'
Search Results
2. Explaining apparent particle shrinkage related to new particle formation events in western Saudi Arabia does not require evaporation
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Hakala, Simo Kalervo, primary, Vakkari, Ville, additional, Lihavainen, Heikki, additional, Hyvärinen, Antti-Pekka, additional, Neitola, Kimmo, additional, Kontkanen, Jenni, additional, Kerminen, Veli-Matti, additional, Kulmala, Markku, additional, Petäjä, Tuukka, additional, Hussein, Tareq, additional, Khoder, Mamdouh I., additional, Alghamdi, Mansour ِA., additional, and Paasonen, Pauli, additional
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- 2023
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- View/download PDF
3. Explaining apparent particle shrinkage related to new particle formation events in western Saudi Arabia does not require evaporation.
- Author
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Hakala, Simo, Vakkari, Ville, Lihavainen, Heikki, Hyvärinen, Antti-Pekka, Neitola, Kimmo, Kontkanen, Jenni, Kerminen, Veli-Matti, Kulmala, Markku, Petäjä, Tuukka, Hussein, Tareq, Khoder, Mamdouh I., Alghamdi, Mansour A., and Paasonen, Pauli
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EVAPORATION (Meteorology) ,SIZE reduction of materials ,AIR masses - Abstract
The majority of new particle formation (NPF) events observed in Hada Al Sham, western Saudi Arabia, during 2013–2015 showed an unusual progression where the diameter of a newly formed particle mode clearly started to decrease after the growth phase. Many previous studies refer to this phenomenon as aerosol shrinkage. We will opt to use the term decreasing mode diameter (DMD) event, as shrinkage bears the connotation of reduction in the sizes of individual particles, which does not have to be the case. While several previous studies speculate that ambient DMD events are caused by evaporation of semivolatile species, no concrete evidence has been provided, partly due to the rarity of the DMD events. The frequent occurrence and large number of DMD events in our observations allow us to perform statistically significant comparisons between the DMD and the typical NPF events that undergo continuous growth. In our analysis, we find no clear connection between DMD events and factors that might trigger particle evaporation at the measurement site. Instead, examination of air mass source areas and the horizontal distribution of anthropogenic emissions in the study region leads us to believe that the observed DMD events could be caused by advection of smaller, less-grown particles to the measurement site after the more-grown ones. Using a Lagrangian single-particle growth model, we confirm that the observed particle size development, including the DMD events, can be reproduced by non-volatile condensation and thus without evaporation. In fact, when considering increasing contributions from a semivolatile compound, we find deteriorating agreement between the measurements and the model. Based on these results, it seems unlikely that evaporation of semivolatile compounds would play a significant role in the DMD events at our measurement site. In the proposed non-volatile explanation, the DMD events are a result of the observed particles having spent an increasing fraction of their lifetime in a lower-growth environment, mainly enabled by the lower precursor vapor concentrations further away from the measurement site combined with decreasing photochemical production of condensable vapors in the afternoon. Correct identification of the cause of the DMD events is important as the fate and the climate relevance of the newly formed particles heavily depend on it – if the particles evaporated, their net contribution to larger and climatically active particle sizes would be greatly reduced. Our findings highlight the importance of considering transport-related effects in NPF event analysis, which is an often overlooked factor in such studies. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
- View/download PDF
4. Explaining apparent particle shrinkage related to new particle formation events in western Saudi Arabia does not require evaporation.
- Author
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Hakala, Simo Kalervo, Vakkari, Ville, Lihavainen, Heikki, Hyvärinen, Antti-Pekka, Neitola, Kimmo, Kontkanen, Jenni, Kerminen, Veli-Matti, Kulmala, Markku, Petäjä, Tuukka, Hussein, Tareq, Khoder, Mamdouh I., Alghamdi, Mansour ِA., and Paasonen, Pauli
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EVAPORATION (Meteorology) ,SIZE reduction of materials ,AIR masses - Abstract
The majority of new particle formation (NPF) events observed in Hada al Sham, western Saudi Arabia during 2013–2015, showed an unusual progression where the diameter of a newly formed particle mode clearly started to decrease after the growth phase. Many previous studies refer to this phenomenon as aerosol shrinkage. We will opt to use the term decreasing mode diameter (DMD) event, as shrinkage bears the connotation of reduction in the sizes of individual particles, which does not have to be the case. While several previous studies speculate that ambient DMD events are caused by evaporation of semivolatile species, no concrete evidence has been provided, partly due to the rarity of the DMD events. The frequent occurrence and large number of DMD events in our observations allow us to perform statistically significant comparisons between the DMD and the typical NPF events that undergo continuous growth. In our analysis, we find no clear connection between DMD events and factors that might trigger particle evaporation at the measurement site. Instead, examination of air mass source areas and the horizontal distribution of anthropogenic emissions in the study region leads us to believe that the observed DMD events could be caused by advection of smaller, less-grown, particles to the measurement site after the more-grown ones. Using a Lagrangian single-particle growth model, we confirm that the observed particle size development, including the DMD events, can be reproduced by non-volatile condensation, and thus without evaporation. In fact, when considering increasing contributions from a semivolatile compound, we find deteriorating agreement between the measurements and the model. Based on these results, it seems unlikely that evaporation of semivolatile compounds would play a significant role in the DMD events at our measurement site. In the proposed non-volatile explanation, the DMD events are a result of the observed particles having spent an increasing fraction of their lifetime in a lower growth environment, mainly enabled by the lower precursor vapor concentrations further away from the measurement site combined with decreasing photochemical production of condensable vapors in the afternoon. The correct identification of the cause of the DMD events is important as the fate and the climate-relevance of the newly formed particles heavily depends on it — if the particles evaporated, their net contribution towards larger and climatically active particle sizes would be greatly reduced. Our findings highlight the importance of considering transport-related effects in NPF event analysis, which is an often overlooked factor in such studies. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
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5. Everyday tips for making the workplace culture welcoming for diverse staff
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Vehkamäki, Hanna, primary, Beck, Lisa, additional, Demakova, Anastasiia, additional, Lauri, Katja Anniina, additional, Li, Xuefei, additional, Lintunen, Anna, additional, Mazon, Stephany B., additional, Neitola, Kimmo, additional, Rajewicz, Paulina, additional, Karppinen, Laura, additional, Nieminen, Tuomo, additional, Schiestl-Aalto, Pauliina, additional, and Vesala, Timo, additional
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- 2022
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6. Measurement report: Long-term measurements of aerosol precursor concentrations in the Finnish subarctic boreal forest
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Jokinen, Tuija, primary, Lehtipalo, Katrianne, additional, Thakur, Roseline Cutting, additional, Ylivinkka, Ilona, additional, Neitola, Kimmo, additional, Sarnela, Nina, additional, Laitinen, Totti, additional, Kulmala, Markku, additional, Petäjä, Tuukka, additional, and Sipilä, Mikko, additional
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- 2022
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7. The role of terrestrial productivity and hydrology in regulating aquatic dissolved organic carbon concentrations in boreal catchments
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Zhu, Xudan, primary, Chen, Liang, additional, Pumpanen, Jukka, additional, Ojala, Anne, additional, Zobitz, John, additional, Zhou, Xuan, additional, Laudon, Hjalmar, additional, Palviainen, Marjo, additional, Neitola, Kimmo, additional, and Berninger, Frank, additional
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- 2022
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8. Wintertime subarctic new particle formation from Kola Peninsula sulfur emissions
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Sipilä, Mikko, primary, Sarnela, Nina, additional, Neitola, Kimmo, additional, Laitinen, Totti, additional, Kemppainen, Deniz, additional, Beck, Lisa, additional, Duplissy, Ella-Maria, additional, Kuittinen, Salla, additional, Lehmusjärvi, Tuuli, additional, Lampilahti, Janne, additional, Kerminen, Veli-Matti, additional, Lehtipalo, Katrianne, additional, Aalto, Pasi P., additional, Keronen, Petri, additional, Siivola, Erkki, additional, Rantala, Pekka A., additional, Worsnop, Douglas R., additional, Kulmala, Markku, additional, Jokinen, Tuija, additional, and Petäjä, Tuukka, additional
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- 2021
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9. The Unmanned Systems Research Laboratory (USRL) : A New Facility for UAV-Based Atmospheric Observations
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Kezoudi, Maria, Keleshis, Christos, Antoniou, Panayiota, Biskos, George, Bronz, Murat, Constantinides, Christos, Desservettaz, Maximillien, Gao, Ru-Shan, Girdwood, Joe, Harnetiaux, Jonathan, Kandler, Konrad, Leonidou, Andreas, Liu, Yunsong, Lelieveld, Jos, Marenco, Franco, Mihalopoulos, Nikos, Mocnik, Grisa, Neitola, Kimmo, Paris, Jean-Daniel, Pikridas, Michael, Sarda-Esteve, Roland, Stopford, Chris, Unga, Florin, Vrekoussis, Mihalis, Sciare, Jean, Institute for Atmospheric and Earth System Research (INAR), and Polar and arctic atmospheric research (PANDA)
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114 Physical sciences - Abstract
The Unmanned Systems Research Laboratory (USRL) of the Cyprus Institute is a new mobile exploratory platform of the EU Research Infrastructure Aerosol, Clouds and Trace Gases Research InfraStructure (ACTRIS). USRL offers exclusive Unmanned Aerial Vehicle (UAV)-sensor solutions that can be deployed anywhere in Europe and beyond, e.g., during intensive field campaigns through a transnational access scheme in compliance with the drone regulation set by the European Union Aviation Safety Agency (EASA) for the research, innovation, and training. UAV sensor systems play a growing role in the portfolio of Earth observation systems. They can provide cost-effective, spatial in-situ atmospheric observations which are complementary to stationary observation networks. They also have strong potential for calibrating and validating remote-sensing sensors and retrieval algorithms, mapping close-to-the-ground emission point sources and dispersion plumes, and evaluating the performance of atmospheric models. They can provide unique information relevant to the short- and long-range transport of gas and aerosol pollutants, radiative forcing, cloud properties, emission factors and a variety of atmospheric parameters. Since its establishment in 2015, USRL is participating in major international research projects dedicated to (1) the better understanding of aerosol-cloud interactions, (2) the profiling of aerosol optical properties in different atmospheric environments, (3) the vertical distribution of air pollutants in and above the planetary boundary layer, (4) the validation of Aeolus satellite dust products by utilizing novel UAV-balloon-sensor systems, and (5) the chemical characterization of ship and stack emissions. A comprehensive overview of the new UAV-sensor systems developed by USRL and their field deployments is presented here. This paper aims to illustrate the strong scientific potential of UAV-borne measurements in the atmospheric sciences and the need for their integration in Earth observation networks.
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- 2021
10. Towards understanding the characteristics of new particle formation in the Eastern Mediterranean
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Baalbaki, Rima, Pikridas, Michael, Jokinen, Tuija, Laurila, Tiia, Dada, Lubna, Bezantakos, Spyros, Ahonen, Lauri, Neitola, Kimmo, Maisser, Anne, Bimenyimana, Elie, Christodoulou, Aliki, Unga, Florin, Savvides, Chrysanthos, Lehtipalo, Katrianne, Kangasluoma, Juha, Biskos, George, Petäjä, Tuukka, Kerminen, Veli-Matti, Sciare, Jean, Kulmala, Markku, Institute for Atmospheric and Earth System Research (INAR), Polar and arctic atmospheric research (PANDA), Air quality research group, and Global Atmosphere-Earth surface feedbacks
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complex mixtures ,114 Physical sciences - Abstract
To quantify the contribution of new particle formation (NPF) to ultrafine particle number and cloud condensation nuclei (CCN) budgets, one has to understand the mechanisms that govern NPF in different environments and its temporal extent. Here, we study NPF in Cyprus, an Eastern Mediterranean country located at the crossroads of three continents and affected by diverse air masses originating from continental, maritime, and desert-dust source areas. We performed 1-year continuous measurements of aerosol particles down to ∼ 1 nm in diameter for the first time in the Eastern Mediterranean and Middle East (EMME) region. These measurements were complemented with trace gas data, meteorological variables, and retroplume analysis. We show that NPF is a very frequent phenomenon at this site and has higher frequencies of occurrence during spring and autumn. NPF events were both of local and regional origin, and the local events occurred frequently during the month with the lowest NPF frequency. Some NPF events exhibited multiple onsets, while others exhibited apparent particle shrinkage in size. Additionally, NPF events were observed during the nighttime and during episodes of high desert-dust loadings. Particle formation rates and growth rates were comparable to those in urban environments, although our site is a rural one. Meteorological variables and trace gases played a role in explaining the intra-monthly variability of NPF events, but they did not explain why summer months had the least NPF frequency. Similarly, pre-existing aerosol loading did not explain the observed seasonality. The months with the least NPF frequency were associated with higher H2SO4 concentrations but lower NO2 concentrations, which is an indicator of anthropogenic influence. Air masses arriving from the Middle East were not observed during these months, which could suggest that precursor vapors important for nucleation and growth are transported to our site from the Middle East. Further comprehensive measurements of precursor vapors are required to prove this hypothesis.
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- 2021
11. Measurement report: Long-term measurements of aerosol precursor concentrations in the Finnish sub-Arctic boreal forest
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Jokinen, Tuija, primary, Lehtipalo, Katrianne, additional, Thakur, Roseline Cutting, additional, Ylivinkka, Ilona, additional, Neitola, Kimmo, additional, Sarnela, Nina, additional, Laitinen, Totti, additional, Kulmala, Markku, additional, Petäjä, Tuukka, additional, and Sipilä, Mikko, additional
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- 2021
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12. The Unmanned Systems Research Laboratory (USRL): A New Facility for UAV-Based Atmospheric Observations
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Kezoudi, Maria, primary, Keleshis, Christos, additional, Antoniou, Panayiota, additional, Biskos, George, additional, Bronz, Murat, additional, Constantinides, Christos, additional, Desservettaz, Maximillien, additional, Gao, Ru-Shan, additional, Girdwood, Joe, additional, Harnetiaux, Jonathan, additional, Kandler, Konrad, additional, Leonidou, Andreas, additional, Liu, Yunsong, additional, Lelieveld, Jos, additional, Marenco, Franco, additional, Mihalopoulos, Nikos, additional, Močnik, Griša, additional, Neitola, Kimmo, additional, Paris, Jean-Daniel, additional, Pikridas, Michael, additional, Sarda-Esteve, Roland, additional, Stopford, Chris, additional, Unga, Florin, additional, Vrekoussis, Mihalis, additional, and Sciare, Jean, additional
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- 2021
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13. Towards understanding the characteristics of new particle formation in the Eastern Mediterranean
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Baalbaki, Rima, primary, Pikridas, Michael, additional, Jokinen, Tuija, additional, Laurila, Tiia, additional, Dada, Lubna, additional, Bezantakos, Spyros, additional, Ahonen, Lauri, additional, Neitola, Kimmo, additional, Maisser, Anne, additional, Bimenyimana, Elie, additional, Christodoulou, Aliki, additional, Unga, Florin, additional, Savvides, Chrysanthos, additional, Lehtipalo, Katrianne, additional, Kangasluoma, Juha, additional, Biskos, George, additional, Petäjä, Tuukka, additional, Kerminen, Veli-Matti, additional, Sciare, Jean, additional, and Kulmala, Markku, additional
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- 2021
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14. Assessment of a portable UV–Vis spectrophotometer's performance in remote areas: Stream water DOC, Fe content and spectral data
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Zhu, Xudan, primary, Chen, Liang, additional, Pumpanen, Jukka, additional, Keinänen, Markku, additional, Laudon, Hjalmar, additional, Ojala, Anne, additional, Palviainen, Marjo, additional, Kiirikki, Mikko, additional, Neitola, Kimmo, additional, and Berninger, Frank, additional
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- 2021
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15. Acute cigarette smoke inhalation blunts lung responsiveness to methacholine and allergen in rabbit: differentiation of central and peripheral effects
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Porra, Liisa, Petak, Ferenc, Strengell, Satu, Neitola, Kimmo, Janosi, Tibor Z., Suhonen, Heikki, Suortti, Pekka, Sovijarvi, Anssi R.A., Habre, Walid, and Bayat, Sam
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Asthma -- Risk factors ,Asthma -- Diagnosis ,Asthma -- Research ,CT imaging -- Usage ,CT imaging -- Health aspects ,Smoking -- Health aspects ,Smoking -- Research ,Biological sciences - Abstract
Despite the prevalence of active smoking in asthmatics, data on the short-term effect of acute mainstream tobacco smoke exposure on airway responsiveness are very scarce. The aim of this study was to assess the immediate effect of acute exposure to mainstream cigarette smoke on airway reactivity to subsequent nonspecific and allergenic challenges in healthy control (n = 5) and ovalbumin-sensitized rabbits (n = 6). We combined low-frequency forced oscillations and synchrotron radiation CT imaging to differentiate central airway and peripheral airway and lung parenchymal components of the response to airway provocation. Acute exposure to smoke generated by four successive cigarettes (CS) strongly inhibited the central airway response to subsequent IV methacholine (MCh) challenge. In the sensitized animals, although the response to ovalbumin was also inhibited in the central airways, mainstream CS did not blunt the peripheral airway response in this group. In additional groups of experiments, exposure to HEPA-filtered CS (n = 6) similarly inhibited the MCh response, whereas CO (10,000 ppm for 4 min, n = 6) or nitric oxide inhalation instead of CS (240 ppm, 4 x 7 min, n = 5) failed to blunt nonspecific airway responsiveness. Pretreatment with [alpha]-chymotrypsin to inhibit endogenous VIP before CS exposure had no effect (n = 4). Based on these observations, the gas phase of mainstream cigarette smoke may contain one or more short-term inhibitory components acting primarily on central airways and inhibiting the response to both specific and nonspecific airway provocation, but not on the lung periphery where both lung mechanical parameters, and synchrotron-imaging derived parameters, showed large changes in response to allergen challenge in sensitized animals. asthma; smoking; tomography; X-ray computed; synchrotrons; respiratory mechanics doi: 10.1152/ajplung.00033.2010.
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- 2010
16. Composition and concentrations of aerosol precursor gases in the sub-Arctic boreal forest
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Jokinen, Tuija, primary, Lehtipalo, Katrianne, additional, Neitola, Kimmo, additional, Sarnela, Nina, additional, Laitinen, Totti, additional, Kulmala, Markku, additional, Petäjä, Tuukka, additional, and Sipilä, Mikko, additional
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- 2021
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17. Wintertime sub-arctic new particle formation from Kola Peninsula sulphur emissions
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Sipilä, Mikko, primary, Sarnela, Nina, additional, Neitola, Kimmo, additional, Laitinen, Totti, additional, Kemppainen, Deniz, additional, Beck, Lisa, additional, Duplissy, Ella-Maria, additional, Kuittinen, Salla, additional, Lehmusjärvi, Tuuli, additional, Lampilahti, Janne, additional, Kerminen, Veli-Matti, additional, Lehtipalo, Katrianne, additional, Aalto, Pasi P., additional, Keronen, Petri, additional, Siivola, Erkki, additional, Rantala, Pekka A., additional, Worsnop, Douglas R., additional, Kulmala, Markku, additional, Jokinen, Tuija, additional, and Petäjä, Tuukka, additional
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- 2021
- Full Text
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18. Supplementary material to "Wintertime sub-arctic new particle formation from Kola Peninsula sulphur emissions"
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Sipilä, Mikko, primary, Sarnela, Nina, additional, Neitola, Kimmo, additional, Laitinen, Totti, additional, Kemppainen, Deniz, additional, Beck, Lisa, additional, Duplissy, Ella-Maria, additional, Kuittinen, Salla, additional, Lehmusjärvi, Tuuli, additional, Lampilahti, Janne, additional, Kerminen, Veli-Matti, additional, Lehtipalo, Katrianne, additional, Aalto, Pasi P., additional, Keronen, Petri, additional, Siivola, Erkki, additional, Rantala, Pekka A., additional, Worsnop, Douglas R., additional, Kulmala, Markku, additional, Jokinen, Tuija, additional, and Petäjä, Tuukka, additional
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- 2021
- Full Text
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19. Towards understanding the mechanisms of new particle formation in the Eastern Mediterranean
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Baalbaki, Rima, primary, Pikridas, Michael, additional, Jokinen, Tuija, additional, Laurila, Tiia, additional, Dada, Lubna, additional, Bezantakos, Spyros, additional, Ahonen, Lauri, additional, Neitola, Kimmo, additional, Maisser, Anne, additional, Bimenyimana, Elie, additional, Christodoulou, Aliki, additional, Unga, Florin, additional, Savvides, Chrysanthos, additional, Lehtipalo, Katrianne, additional, Kangasluoma, Juha, additional, Biskos, George, additional, Petäjä, Tuukka, additional, Kerminen, Veli-Matti, additional, Sciare, Jean, additional, and Kulmala, Markku, additional
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- 2020
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20. Supplementary material to "Towards understanding the mechanisms of new particle formation in the Eastern Mediterranean"
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Baalbaki, Rima, primary, Pikridas, Michael, additional, Jokinen, Tuija, additional, Laurila, Tiia, additional, Dada, Lubna, additional, Bezantakos, Spyros, additional, Ahonen, Lauri, additional, Neitola, Kimmo, additional, Maisser, Anne, additional, Bimenyimana, Elie, additional, Christodoulou, Aliki, additional, Unga, Florin, additional, Savvides, Chrysanthos, additional, Lehtipalo, Katrianne, additional, Kangasluoma, Juha, additional, Biskos, George, additional, Petäjä, Tuukka, additional, Kerminen, Veli-Matti, additional, Sciare, Jean, additional, and Kulmala, Markku, additional
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- 2020
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21. Measurement report: Long-term measurements of aerosol precursor concentrations in the Finnish sub-Arctic boreal forest.
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Jokinen, Tuija, Lehtipalo, Katrianne, Thakur, Roseline Cutting, Ylivinkka, Ilona, Neitola, Kimmo, Sarnela, Nina, Laitinen, Totti, Kulmala, Markku, Petäjä, Tuukka, and Sipilä, Mikko
- Abstract
Aerosol particles form in the atmosphere by clustering of certain atmospheric vapors. After growing to larger particles by condensation of low volatile gases, they can affect the Earth's climate directly by scattering light and indirectly by acting as cloud condensation nuclei. Observations of low-volatility aerosol precursor gases have been reported around the world but longer-term measurement series and any Arctic data sets showing seasonal variation are close to non-existent. In here, we present ~7 months of aerosol precursor gas measurements performed with the nitrate based chemical ionization mass spectrometer (CI-APi-TOF). We deployed our measurements ~150 km North of the Arctic Circle at the continental Finnish sub-Arctic field station, SMEAR I, located in Värriö strict nature reserve. We report concentration measurements of the most common new particle formation related compounds; sulfuric acid (SA), methane sulfonic acid (MSA), iodic acid (IA) and a total concentration of highly oxygenated organic compounds (HOMs). At this remote measurement site, SA is originated both from anthropogenic and biological sources and has a clear diurnal cycle but no significant seasonal variation. MSA shows a more distinct seasonal cycle with concentrations peaking in the summer. Of the measured compounds, iodic acid concentrations are the most stable throughout the measurement period, except in April, when the concentration of IA is significantly higher than during the rest of the year. Otherwise, IA has almost identical daily maximum concentrations in spring, summer and autumn, and on new particle formation event or non-event days. HOMs are abundant during the summer months and low in winter months. Due to the low winter concentrations and their high correlation with ambient air temperature, we suggest that most of HOMs are products of biogenic emissions, most probably monoterpene oxidation products. New particle formation events at SMEAR I happen under relatively low temperatures with a fast temperature rise in the morning followed by decreasing relative humidity during the day. The ozone concentrations are on average ~10 ppbv higher on NPF days than non-event days. During NPF days, we have on average higher SA concentration peaking at noon, higher MSA concentrations in the afternoon and slightly higher IA concentration than during non-event days. All together, these are the first long term measurements of aerosol forming vapors from the SMEAR I in the sub-arctic region, and the results help us to understand atmospheric chemical processes and aerosol formation in the rapidly changing Arctic. [ABSTRACT FROM AUTHOR]
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- 2021
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22. Shipborne vertical profiles of dust aerosols obtained with Unmanned Aerial Vehicles in the Mediterranean and the Middle East: First results ofthe AQABA campaign
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Neitola, Kimmo, Bronz, Murat, Keleshis, Christos, Vouterakos, Panagiotis, Antoniou, Panayiota, Barmpounis, Konstantinos, Yannick, Jestin, Lelieveld, Jos, Sciare, Jean, Porte, Laurence, Cyprus Institute (CyI), Ecole Nationale de l'Aviation Civile (ENAC), Max-Planck-Institut für Biophysik - Max Planck Institute of Biophysics (MPIBP), and Max-Planck-Gesellschaft
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[SPI.AUTO] Engineering Sciences [physics]/Automatic ,[SPI.AUTO]Engineering Sciences [physics]/Automatic - Abstract
International audience; Atmospheric aerosols have a large role in the earth climate through direct or indirect effects on the radiative energy budget. As the aerosol characteristics are highly variable spatially and in time, observations of these characteristics are needed in regions, where the climate change effects are the most severe. One of these types of hotspots is the East Mediterranean and Middle East (EMME region) (Lelieveld et al., 2012), however, high quality in-situ observations in the Middle East and Arabian Peninsula region are still missing. To gain such a high quality observations in this region, the "Air Quality and climate change in the Arabian Basin" (AQABA) oceanographic campaign was organized during summer 2017, shipping from France, through the Suez Canal and around the Arabian Peninsula to Kuwait and back to France. The total length of the campaign was more than 2 months. A wide spectrum of environmental conditions was encountered during the campaign, ranging from pristine conditions over the Indian Ocean, to dusty (low polluted) atmosphere in the Red Sea affected by the Saharan dust and the highly dusty and polluted Gulf. To add on the remote sensing data of aerosol characteristics above the sea surface collected on the ship, the Cyprus Institute's Unmanned Systems Research Laboratory (USRL) team deployed Unmanned Aerial Vehicles (UAVs) to gain in-situ observations of aerosol properties inside and above the marine boundary layer. A small, fixed wing UAV was hand launched from the ship, which then climbed up to 2000 m (a.s.l.) and then returned to the ship and landed on a net. A modified AlphaSense N-2 Optical Particle Counter (OPC) was used on board the UAV to observe the number size distribution of aerosol particles (range: 0.38-17.5 µm, with 16 channels). Meteorological parameters (T, RH and P), as well as a video was recorded also. A total of 16 Successful flights were made, mostly in the Mediterranean and in the Persian Gulf, with few flights in the Red Sea and the Arabian Sea. The presentation will show data acquired on board the UAVs and comparison with ceilometer data obtained on the ship to identify possible dust layers and other interesting events. The differences in aerosol size distributions inside and above the boundary layer will be discussed, as well as any interesting case studies or events during the measurements.
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- 2018
23. New particle formation, growth and apparent shrinkage at a rural background site in western Saudi Arabia
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Hakala, Simo, primary, Alghamdi, Mansour A., additional, Paasonen, Pauli, additional, Vakkari, Ville, additional, Khoder, Mamdouh I., additional, Neitola, Kimmo, additional, Dada, Lubna, additional, Abdelmaksoud, Ahmad S., additional, Al-Jeelani, Hisham, additional, Shabbaj, Ibrahim I., additional, Almehmadi, Fahd M., additional, Sundström, Anu-Maija, additional, Lihavainen, Heikki, additional, Kerminen, Veli-Matti, additional, Kontkanen, Jenni, additional, Kulmala, Markku, additional, Hussein, Tareq, additional, and Hyvärinen, Antti-Pekka, additional
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- 2019
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- View/download PDF
24. New particle formation, growth and shrinkage at a rural background site in western Saudi Arabia
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Hakala, Simo, primary, Alghamdi, Mansour A., additional, Paasonen, Pauli, additional, Khoder, Mamdouh, additional, Neitola, Kimmo, additional, Vakkari, Ville, additional, Sundström, Anu-Maija, additional, Kontkanen, Jenni, additional, Abdelmaksoud, Ahmad S., additional, Al-Jeelani, Hisham, additional, Lihavainen, Heikki, additional, Hussein, Tareq, additional, Kulmala, Markku, additional, Kerminen, Veli-Matti, additional, Hyvärinen, Antti-Pekka, additional, Shabbaj, Ibrahim I., additional, and Almehmadi, Fahd M., additional
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- 2019
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- View/download PDF
25. Wintertime sub-arctic new particle formation from Kola Peninsula sulphur emissions.
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Sipilä, Mikko, Sarnela, Nina, Neitola, Kimmo, Laitinen, Totti, Kemppainen, Deniz, Beck, Lisa, Duplissy, Ella-Maria, Kuittinen, Salla, Lehmusjärvi, Tuuli, Lampilahti, Janne, Kerminen, Veli-Matti, Lehtipalo, Katrianne, Aalto, Pasi P., Keronen, Petri, Siivola, Erkki, Rantala, Pekka A., Worsnop, Douglas R., Kulmala, Markku, Jokinen, Tuija, and Petäjä, Tuukka
- Abstract
Metallurgical industry in Kola peninsula, North-West Russia, form a second largest source of air pollution in the Arctic and sub-Arctic domain. Sulphur dioxide emissions from the ore smelters are transported to wide areas including Finnish Lapland. We performed investigations on concentrations of SO
2 and aerosol precursor vapours, aerosol and ion cluster size distributions together with chemical composition measurements of freshly formed clusters at SMEAR I station in Finnish Lapland relatively close (~300 km) to Kola peninsula industrial sites during winter 2019-2020. We show that highly concentrated SO2 from smelter emissions is converted to sulphuric acid (H2 SO4 ) with sufficient concentrations to drive new particle formation hundreds of kilometres downwind of the emission sources even with very low solar radiation intensities. Observed new particle formation is primarily initiated by H2 SO4 - ammonia (negative-) ion induced nucleation. Particle growth to cloud condensation nuclei (CCN) sizes was concluded to result from sulphuric acid condensation. However, airmass advection had a large role in modifying aerosol size distributions and other growth mechanisms cannot be fully excluded. Our results demonstrate the dominance of SO2 emissions in controlling winter-time aerosol and CCN concentrations in the subarctic region with heavily polluting industry. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
26. Homogenous nucleation rates of n-propanol measured in the Laminar Flow Diffusion Chamber at different total pressures.
- Author
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Görke, Hanna, Neitola, Kimmo, Hyvärinen, Antti-Pekka, Lihavainen, Heikki, Wölk, Judith, Strey, Reinhard, and Brus, David
- Subjects
- *
NUCLEATION , *LAMINAR flow , *PROPANOLS , *DROPLETS , *CARRIER gas , *PENTANOL - Abstract
Nucleation rates of n-propanol were investigated in the Laminar Flow Diffusion Chamber. Nucleation temperatures between 270 and 300 K and rates between 100 and 106 cm−3 s−1 were achieved. Since earlier measurements of n-butanol and n–pentanol suggest a dependence of nucleation rates on carrier gas pressure, similar conditions were adjusted for these measurements. The obtained data fit well to results available from literature. A small positive pressure effect was found which strengthen the assumption that this effect is attributed to the carbon chain length of the n-alcohol [D. Brus, A. P. Hyvärinen, J. Wedekind, Y. Viisanen, M. Kulmala, V. Ždímal, J. Smolík, and H. Lihavainen, J. Chem. Phys. 128, 134312 (2008)] and might be less intensive for substances in the homologous series with higher equilibrium vapor pressure. A comparison with the theoretical approach by Wedekind et al. [Phys. Rev. Lett. 101, 12 (2008)] shows that the effect goes in the same direction but that the intensity is much stronger in experiments than in theory. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
27. Towards understanding the mechanisms of new particle formation in the Eastern Mediterranean.
- Author
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Baalbaki, Rima, Pikridas, Michael, Jokinen, Tuija, Laurila, Tiia, Dada, Lubna, Bezantakos, Spyros, Ahonen, Lauri, Neitola, Kimmo, Maisser, Anne, Bimenyimana, Elie, Christodoulou, Aliki, Unga, Florin, Savvides, Chrysanthos, Lehtipalo, Katrianne, Kangasluoma, Juha, Biskos, George, Petäjä, Tuukka, Kerminen, Veli-Matti, Sciare, Jean, and Kulmala, Markku
- Abstract
To quantify the contribution of new particle formation (NPF) to ultrafine particle number and CCN budgets, one has to understand the mechanisms that govern NPF in different environments and its temporal extent. Here, we study NPF in Cyprus, an Eastern Mediterranean country located at the crossroads of three continents. We performed one-year continuous measurements of aerosol particles down to ~ 1 nm in diameter, for the first time in the Eastern Mediterranean and Middle East (EMME) region. These measurements were complemented with trace gas data, meteorological variables and retroplume analysis. We show that NPF is a very frequent phenomenon at this site and has higher frequencies of occurrence during spring and autumn. NPF events were both of local and regional origin, and the local events occurred frequently during the month with the lowest NPF frequency. Some NPF events exhibited multiple onsets, while others exhibited particle apparent shrinkage in size. Additionally, NPF events were observed during the night-time and during episodes of high desert dust loadings. Particle formation rates and growth rates were comparable to those in urban environments, although our site is a rural one. Meteorological variables and trace gases played a role in explaining the intra-monthly variability of NPF events, but did not explain why summer month had the least NPF frequency. Similarly, pre-existing aerosol loading did not explain the observed seasonality. The month with the least NPF frequency were associated with higher H
2 SO4 concentrations but lower NOx concentration, which is an indicator of anthropogenic influence. Air masses arriving from the Middle East were not observed during these month, which could suggest that precursor vapors important for nucleation and growth are transported to our site from the Middle East. Further comprehensive measurements of precursor vapors are required to prove this hypothesis. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
28. Primary sources control the variability of aerosol optical properties in the Antarctic Peninsula
- Author
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Asmi, Eija, primary, Neitola, Kimmo, additional, Teinilä, Kimmo, additional, Rodriguez, Edith, additional, Virkkula, Aki, additional, Backman, John, additional, Bloss, Matthew, additional, Jokela, Jesse, additional, Lihavainen, Heikki, additional, De Leeuw, Gerrit, additional, Paatero, Jussi, additional, Aaltonen, Veijo, additional, Mei, Miguel, additional, Gambarte, Gonzalo, additional, Copes, Gustavo, additional, Albertini, Marco, additional, Fogwill, Germán Pérez, additional, Ferrara, Jonathan, additional, Barlasina, María Elena, additional, and Sánchez, Ricardo, additional
- Published
- 2018
- Full Text
- View/download PDF
29. Experimental studies on nucleation and new particle formation
- Author
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Neitola, Kimmo, University of Helsinki, Faculty of Science, Department of Physics, Finnish Meteorological Institute, Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysiikan laitos, Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysik, Smith, James, Kulmala, Markku, Lihavainen, Heikki, and Brus, David
- Subjects
fysiikka - Abstract
Aerosols affect our everyday life in many ways. Changes in visibility, allergies to pollen, spray cans and dosing of some medication are just a few examples of common aerosols. Aerosols may have more profound way to affect every one of us; through climate. Possible changes in aerosol particle concentrations and compositions may alter large precipitation patterns and change cloud albedo, and lifetime. To be able to predict future changes in climate, profound understating of physical and chemical processes affecting the atmospheric aerosol population is crucial. Nucleation, i.e. gas-to-liquid phase transition, is the fundamental step in particle formation in the atmosphere. Sulphuric acid is established to be one of key components in atmospheric nucleation, but other stabilizing species are needed to participate in the process to ex-plain atmospheric nucleation. The identity of these species and the mechanisms of the process itself have been elusive. This thesis aims to gain insight on the species participating nucleation and the mechanism of the whole process. This thesis concentrates first to identify meteorological parameters controlling the atmos-pheric new particle formation. The information gathered from the field is used to design laboratory experiments more precise for the purpose of studying nucleation. The laboratory experiments were carried out using different flow tubes, first to test the limits of the Clas-sical Nucleation Theory and later on to investigate sulphuric acid-water binary and sul-phuric acid-water-base compound ternary nucleation. The precursor gas species were measured using mass spectrometers and ion chromatographs. The measured concentration of sulphuric acid from gas and particle phases were compared to theoretical prediction. The magnitude of the effect of base compounds on nucleation was estimated. The clustering of sulphuric acid molecules with other species was detected. Initial growth of clusters were studied in the point of view of sulphate containing species. The results from the laboratory experiments confirmed earlier results found in the literature that base compounds increase nucleation rates significantly. The measurements of the gas-phase concentrations of these compounds set an upper limit, where the increasing effect is saturated. Comparison of the sulphuric acid concentrations measured with different tech-niques and with the theoretical approach showed order-of-magnitude discrepancy. The discrepancy was found to be due to clustering of sulphuric acid molecules with various species. Sulphate-containing species was found to be responsible of the initial growth of clusters in the flow tube measurements. Even though the species participating nucleation are still an open question, the work done in this thesis has helped to identify few of these species and the magnitude of their effect on nucleation. This thesis also helps to under-stand the initial growth of clusters in flow tube experiments and to identify possible limitation on instruments used commonly in atmospheric measurements. Aerosolit vaikuttavat meidän jokapäiväisessä elämässä monin tavoin. Muutokset näkyvyydessä, siitepölyallergiat, suihkepullot ja lääkkeiden annostelut ovat vain muutamia esimerkkejä tyypillisistä aerosoleista. Aerosoleilla voi olla syvällisempi vaikutus meidän kaikkien elämään; ilmaston kautta. Mahdolliset muutokset aerosolihiukkasten pitoisuuksissa ja rakenteessa voivat muuttaa suuria sademalleja ja pilvien albedoa sekä elinaikaa. Jotta voitaisiin ennustaa tulevia muutoksia ilmastossa, aerosolipopulaation vaikuttavat fysikaaliset ja kemialliset prosessit tulee ymmärtää perusteellisesti. Nukleaatio, eli kaasusta nesteeksi-faasitransitio, on ilmakehän aerosolimuodostumisen olennainen askel. Rikkihappo on tunnistettu yhdeksi avainkomponentiksi ilmakehän nukleaatiossa, mutta muita stabilisoivia yhdisteitä tarvitaan mukaan itse prosessiin, jotta ilmakehän nukleaatio olisi selitettävissä. Nämä yhdisteet, sekä itse nukleaatioprosessin mekanismi ovat pysyneet mysteerinä. Tämä väitöskirja pyrkii lisäämään ymmärrystä mitkä yhdisteet osallistuvat nukleatioon ja ymmärtämään nukleaation mekanismia. Tässä väitöskirjassa keskitytään aluksi tunnistamaan meteorologisiin parametreihin, jotka kontrolloivat ilmakehän uusien hiukkasten muodostumista. Kenttämittauksista saatua informaatiota käytettiin laboratorionukleaatiokokeiden tarkkaan suunnitteluun. Laboratoriokokeet suoritettiin käyttämällä erilaisia virtausputkia, joilla testattiin Klassisen nukleaatioteorian rajoja ja rikkihapon ja veden binääristä, sekä rikkihapon, veden ja emäksisen aineen terniääristä nukleaatiota. Nukleaatiota edeltävien kaasujen pitoisuudet mitattiin käyttäen massaspektrometriaa ja ionikromatografiaa. Mitattuja rikkihappopitoisuuksia kaasu- sekä hiukkasfaasissa verrattiin teoreettisiin ennusteisiin. Emäksien aineiden vaikutus nukleaatioon on arvioitu. Rikkihappomolekyylien havaittiin klusteroituvan muiden yhdisteiden kanssa. Työssä tutkittiin sulfaattia sisältävien yhdisteiden vaikutusta klustereiden varhaiseen kasvuun. Laboratoriokokeiden tulokset vahvistivat kirjallisuudessa julkaistuja tuloksia, joiden mukaan emäksiset yhdisteet voivat lisätä nukleaationopeutta huomattavasti. Näiden emäksien yhdisteiden mitatut pitoisuudet kaasufaasissa asettivat ylärajan, jolla nukleaationopeuden kasvu saturoitui. Vertailu eri tekniikoilla mitattujen rikkihappopitoisuuksien, sekä teoreettisten ennusteiden välillä osoitti näiden eroavan yli kertaluokalla. Tämä ero osoittautui johtuvan rikkihappomolekyylien klusteroitumisesta muiden yhdisteiden kanssa. Sulfaattia sisältävien yhdisteiden huomattiin vastaavan klustereiden varhaisesta kasvusta lähes kokonaan virtausputkimittauksissa. Vaikka nukleaatioon osallistuvat yhdisteet ovat vieläkin avoin kysymys, tässä väitöskirjassa tehty työ on auttanut tunnistamaan joitain näistä yhdisteistä, sekä niiden nukleaatiovaikutuksen suuruusluokan. Tämä väitöskirja myös auttaa ymmärtämään klustereiden varhaista kasvua virtausputkikokeissa, sekä ymmärtämään joidenkin yleisesti ilmakehämittauksissa käytettyjen instrumenttien rajoitteita.
- Published
- 2015
30. New particle formation, growth and shrinkage at a rural background site in western Saudi Arabia.
- Author
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Hakala, Simo, Alghamdi, Mansour A., Paasonen, Pauli, Khoder, Mamdouh, Neitola, Kimmo, Vakkari, Ville, Sundström, Anu-Maija, Kontkanen, Jenni, Abdelmaksoud, Ahmad S., Al-Jeelani, Hisham, Lihavainen, Heikki, Hussein, Tareq, Kulmala, Markku, Kerminen, Veli-Matti, Hyvärinen, Antti-Pekka, Shabbaj, Ibrahim I., and Almehmadi, Fahd M.
- Abstract
Atmospheric aerosols have significant effects on human health and the climate. A large fraction of these aerosols originates from secondary new particle formation (NPF), where atmospheric vapors form small particles that subsequently grow into larger sizes. In this study, we characterize NPF events observed at a rural background site of Hada Al Sham (21.802° N, 39.729° E), located in western Saudi-Arabia, during the years 2013–2015. Our analysis shows that NPF events occur very frequently at the site, as 73 % of all the 454 classified days were NPF days. The high NPF frequency is likely 20 explained by the typically prevailing conditions of clear skies and high solar radiation, in combination with sufficient amounts of precursor vapors for particle formation and growth. In Hada Al Sham, the precursor vapors seem to be related to the transport of anthropogenic emissions from the coastal urban and industrial areas, since no NPF events are observed in air masses coming from the sparsely inhabited inland. The median particle formation and growth rates for the NPF days were 8.7 cm
−3 s−1 (J7nm ) and 7.4 nm h−1 (GR7–12nm ), respectively, both showing highest values during late summer. In addition, the 25 formation and growth rates increase as a function of the condensation sink, likely reflecting the common anthropogenic sources of large primary particles and NPF precursor vapors. 76 % of the NPF days showed an unusual progression, where the observed diameter of the newly formed particle mode started to decrease after the growth phase. In comparison to most long-term measurements, the NPF events in Hada Al Sham are exceptionally frequent and strong. In addition, the frequency of the decreasing mode diameter events is higher than anywhere else in the world. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
31. Soot-doped natural snow and its albedo -- results from field experiments.
- Author
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Svensson, Jonas, Virkkula, Aki, Meinander, Outi, Kivekäs, Niku, Hannula, Henna-Reetta, Järvinen, Onni, Peltoniemi, Jouni I., Gritsevich, Maria, Heikkilä, Anu, Kontu, Anna, Neitola, Kimmo, Brus, David, Dagsson-Waldhauserova, Pavla, Anttila, Kati, Vehkamäki, Marko, Hienola, Anca, de Leeuw, Gerrit, and Lihavainen, Heikki
- Abstract
Soot has a pronounced effect on the cryosphere and experiments are still needed to reduce the associated uncertainties. This work presents a series of experiments to address this issue, with soot being deposited onto a natural snow surface after which the albedo changes were monitored. The albedo reduction was the most pronounced for the snow with higher soot content, and it was observed immediately following soot deposition. Compared with a previous laboratory study the effects of soot on the snow were not as prominent in outdoor conditions. During snowmelt, about 50% of the originally deposited soot particles were observed to remain at the snow surface. More detailed experiments are however needed to better explain soot's effect on snow and to better quantify this effect. Our albedo versus soot parameterization agreed relatively well with previously published relationships. [ABSTRACT FROM AUTHOR]
- Published
- 2016
32. Effect of addition of four base compounds on sulphuric-acid--water new-particle formation: a laboratory study.
- Author
-
Neitola, Kimmo, Brus, David, Makkonen, Ulla, Sipilä, Mikko, Lihavainen, Heikki, and Kulmala, Markku
- Abstract
Effect of four different base compounds [ammonia (NH
3 ), monomethyl-(MMA), dimethyl- (DMA) and trimethylamine (TMA)] on sulphuric-acid-water nucleation was studied using a laminar flow tube. The concentration and size distribution of freshly-formed particles were monitored with an Ultrafine Condensation Particle Counters (UCPC) and a Differential Mobility Particle Sizer (DMPS) system. Two separate experiments were conducted. In the first experiment, the sulphuric acid concentration was measured using a mass spectrometer and the amount of base compound input was determined. In the second experiment, the concentration of base compounds in the flow tube was directly measured with an online ion chromatograph. All experiments were conducted at the constant temperature of 298 K and relative humidity of 30%, as well as constant sulphuric acid concentration. The concentration of the added base compounds was increased stepwise from 27 up to 25 000 pptv. An enhancement of the particle nucleation rate was observed only with TMA, and the maximum enhancement factor (EF) was approximately 5.5 at the TMA concentration of 2500 pptv. The possible nucleation enhancement by the other base substances was most probably saturated due to background contaminant levels of DMA, MMA and NH3 . Detection of the base compounds was discussed, and the results obtained in this study were compared with those from other similar laboratory experiments found in literature. [ABSTRACT FROM AUTHOR]- Published
- 2014
33. Effect of addition of four base compounds on sulphuric-acid-water new-particle formation: a laboratory study
- Author
-
Neitola, Kimmo, Brus, David, Makkonen, Ulla, Sipila, Mikko, Lihavainen, Heikki, Markku Kulmala, Department of Physics, and Polar and arctic atmospheric research (PANDA)
- Subjects
HOMOGENEOUS NUCLEATION ,EXPERIMENTAL SETUP ,GAS ,education ,ATMOSPHERIC AEROSOL NUCLEATION ,H2SO4 ,AMMONIUM ,RATES ,ALIPHATIC-AMINES ,114 Physical sciences ,TERNARY NUCLEATION ,NITRATE
34. Shipborne vertical profiles of dust aerosols obtained with Unmanned Aerial Vehicles in the Mediterranean and the Middle East: First results of the AQABA campaign.
- Author
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Neitola, Kimmo, Bronz, Murat, Keleshis, Christos, Vouterakos, Panagiotis, Antoniou, Panayiota, Barmpounis, Konstantinos, Jestin, Yannick, Lelieveld, Jos, and Sciare, Jean
- Subjects
- *
DRONE aircraft , *MINERAL dusts , *AEROSOLS , *DUST - Published
- 2018
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