Auflistung nach Autor:in "Kulmala, Markku"
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- PublikationA synthesis of cloud condensation nuclei counter (CCNC) measurements within the EUCAARI network(Copernicus, 2015) Paramonov, Mikhail; Kerminen, Veli-Matti; Gysel, Martin; Aalto, P. P.; Andreae, Meinrat O.; Asmi, Eija; Baltensperger, Urs; Bougiatioti, Aikaterini; Brus, David; Frank, Göran; Good, N.; Gunthe, Sachin S.; Hao, Liqing; Irwin, M.; Jaatinen, A.; Jurányi, Zsófia; King, S. M.; Kortelainen, A.; Kristensson, Adam; Lihavainen, Heikki; Kulmala, Markku; Lohmann, Ulrike; Martin, Scot T.; McFiggans, Gordon; Mihalopoulos, Nikolaos; Nenes, Athanasios; O'Dowd, Colin; Ovadnevaite, Jurgita; Petäjä, Tuukka; Pöschl, Ulrich; Roberts, Greg; Rose, D.; Svenningsson, Brigitta; Swietlicki, Erik; Weingartner, Ernest; Whitehead, James; Wiedensohler, Alfred; Wittbom, Cerina; Sierau, Berko [in: Atmospheric Chemistry and Physics]Cloud condensation nuclei counter (CCNC) measurements performed at 14 locations around the world within the European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) framework have been analysed and discussed with respect to the cloud condensation nuclei (CCN) activation and hygroscopic properties of the atmospheric aerosol. The annual mean ratio of activated cloud condensation nuclei (NCCN) to the total number concentration of particles (NCN), known as the activated fraction A, shows a similar functional dependence on supersaturation S at many locations – exceptions to this being certain marine locations, a free troposphere site and background sites in south-west Germany and northern Finland. The use of total number concentration of particles above 50 and 100 nm diameter when calculating the activated fractions (A50 and A100, respectively) renders a much more stable dependence of A on S; A50 and A100 also reveal the effect of the size distribution on CCN activation. With respect to chemical composition, it was found that the hygroscopicity of aerosol particles as a function of size differs among locations. The hygroscopicity parameter κ decreased with an increasing size at a continental site in south-west Germany and fluctuated without any particular size dependence across the observed size range in the remote tropical North Atlantic and rural central Hungary. At all other locations κ increased with size. In fact, in Hyytiälä, Vavihill, Jungfraujoch and Pallas the difference in hygroscopicity between Aitken and accumulation mode aerosol was statistically significant at the 5 % significance level. In a boreal environment the assumption of a size-independent κ can lead to a potentially substantial overestimation of NCCN at S levels above 0.6 %. The same is true for other locations where κ was found to increase with size. While detailed information about aerosol hygroscopicity can significantly improve the prediction of NCCN, total aerosol number concentration and aerosol size distribution remain more important parameters. The seasonal and diurnal patterns of CCN activation and hygroscopic properties vary among three long-term locations, highlighting the spatial and temporal variability of potential aerosol–cloud interactions in various environments.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationAerosol decadal trends – Part 2. In-situ aerosol particle number concentrations at GAW and ACTRIS stations(Copernicus, 2013) Asmi, Ari; Collaud Coen, Martine; Ogren, John A.; Andrews, Elisabeth; Sheridan, Patrick; Jefferson, Anne; Weingartner, Ernest; Baltensperger, Urs; Bukowiecki, Nicolas ; Lihavainen, Heikki; Kivekäs, Niku; Asmi, Eija; Aalto, P. P.; Kulmala, Markku; Wiedensohler, Alfred; Birmili, Wolfram; Hamed, Amar; O'Dowd, Colin; Jennings, Stephen G.; Weller, Rolf; Flentje, Harald; Fjaeraa, Ann Mari; Fiebig, Markus; Myhre, Cathrine Lund; Hallar, Anna Gannet; Swietlicki, Erik; Kristensson, Adam; Laj, Paolo [in: Atmospheric Chemistry and Physics]We have analysed the trends of total aerosol particle number concentrations (N) measured at long-term measurement stations involved either in the Global Atmosphere Watch (GAW) and/or EU infrastructure project ACTRIS. The sites are located in Europe, North America, Antarctica, and on Pacific Ocean islands. The majority of the sites showed clear decreasing trends both in the full-length time series, and in the intra-site comparison period of 2001–2010, especially during the winter months. Several potential driving processes for the observed trends were studied, and even though there are some similarities between N trends and air temperature changes, the most likely cause of many northern hemisphere trends was found to be decreases in the anthropogenic emissions of primary particles, SO2 or some co-emitted species. We could not find a consistent agreement between the trends of N and particle optical properties in the few stations with long time series of all of these properties. The trends of N and the proxies for cloud condensation nuclei (CCN) were generally consistent in the few European stations where the measurements were available. This work provides a useful comparison analysis for modelling studies of trends in aerosol number concentrations.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationA European aerosol phenomenology - 6. Scattering properties of atmospheric aerosol particles from 28 ACTRIS sites(Copernicus, 2018) Pandolfi, Marco; Alados-Arboledas, Lucas; Alastuey, Andrés; Andrade, Marcos; Angelov, Christo; Artiñano, Begoña; Backman, John; Baltensperger, Urs; Bonasoni, Paolo; Bukowiecki, Nicolas; Collaud Coen, Martine; Conil, Sébastien; Coz, Esther; Crenn, Vincent; Dudoitis, Vadimas; Ealo, Marina; Eleftheriadis, Kostas; Favez, Olivier; Fetfatzis, Prodromos; Fiebig, Markus; Flentje, Harald; Ginot, Patrick; Gysel, Martin; Henzing, Bas; Hoffer, Andras; Holubova Smejkalova, Adela; Kalapov, Ivo; Kalivitis, Nikos; Kouvarakis, Giorgos; Kristensson, Adam; Kulmala, Markku; Lihavainen, Heikki; Lunder, Chris; Luoma, Krista; Lyamani, Hassan; Marinoni, Angela; Mihalopoulos, Nikolaos; Moerman, Marcel; Nicolas, José; O'Dowd, Colin; Petäjä, Tuukka; Petit, Jean-Eudes; Pichon, Jean Marc; Prokopciuk, Nina; Putaud, Jean-Philippe; Rodríguez, Sergio; Sciare, Jean; Sellegri, Karine; Swietlicki, Erik; Titos, Gloria; Tuch, Thomas; Tunved, Peter; Ulevicius, Vidmantas; Vaishya, Aditya; Vana, Milan; Virkkula, Aki; Vratolis, Stergios; Weingartner, Ernest; Wiedensohler, Alfred; Laj, Paolo [in: Atmospheric Chemistry and Physics]This paper presents the light-scattering properties of atmospheric aerosol particles measured over the past decade at 28 ACTRIS observatories, which are located mainly in Europe. The data include particle light scattering (σsp) and hemispheric backscattering (σbsp) coefficients, scattering Ångström exponent (SAE), backscatter fraction (BF) and asymmetry parameter (g). An increasing gradient of σsp is observed when moving from remote environments (arctic/mountain) to regional and to urban environments. At a regional level in Europe, σsp also increases when moving from Nordic and Baltic countries and from western Europe to central/eastern Europe, whereas no clear spatial gradient is observed for other station environments. The SAE does not show a clear gradient as a function of the placement of the station. However, a west-to-east-increasing gradient is observed for both regional and mountain placements, suggesting a lower fraction of fine-mode particle in western/south-western Europe compared to central and eastern Europe, where the fine-mode particles dominate the scattering. The g does not show any clear gradient by station placement or geographical location reflecting the complex relationship of this parameter with the physical properties of the aerosol particles. Both the station placement and the geographical location are important factors affecting the intra-annual variability. At mountain sites, higher σsp and SAE values are measured in the summer due to the enhanced boundary layer influence and/or new particle-formation episodes. Conversely, the lower horizontal and vertical dispersion during winter leads to higher σsp values at all low-altitude sites in central and eastern Europe compared to summer. These sites also show SAE maxima in the summer (with corresponding g minima). At all sites, both SAE and g show a strong variation with aerosol particle loading. The lowest values of g are always observed together with low σsp values, indicating a larger contribution from particles in the smaller accumulation mode. During periods of high σsp values, the variation of g is less pronounced, whereas the SAE increases or decreases, suggesting changes mostly in the coarse aerosol particle mode rather than in the fine mode. Statistically significant decreasing trends of σsp are observed at 5 out of the 13 stations included in the trend analyses. The total reductions of σsp are consistent with those reported for PM2.5 and PM10 mass concentrations over similar periods across Europe.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationContribution of sulfuric acid and oxidized organic compounds to particle formation and growth(Copernicus, 2012) Riccobono, Francesco; Rondo, Linda; Sipilä, Mikko; Barmet, Peter; Curtius, Joachim; Dommen, Josef; Ehn, Mikael; Ehrhart, Sebastian; Kulmala, Markku; Kürten, Andreas; Mikkilä, Jyri; Paasonen, Pauli; Petäjä, Tuukka; Weingartner, Ernest; Baltensperger, Urs [in: Atmospheric Chemistry and Physics]Abstract. Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to the formation and early growth of nucleated particles. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and α-pinene) showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two chemical ionization mass spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene. New analysis methods were applied to the data collected with a condensation particle counter battery and a scanning mobility particle sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (Γ), defined as the ratio between the measured growth rate in the presence of α-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed Γ values indicate that the growth is already dominated by organic compounds at particle diameters of 2 nm. Both the absolute growth rates and Γ showed a strong dependence on particle size, supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particle growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. Finally, the size resolved growth analysis indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationEvolution of nanoparticle composition in CLOUD in presence of sulphuric acid, ammonia and organics(AIP Publishing, 24.06.2013) Keskinen, Helmi; Virtanen, Annele; Joutsensaari, Jorma; Tsagkogeorgas, Georgios; Duplissy, Jonathan; Schobesberger, Siegfried; Gysel, Martin; Riccobono, Francesco; Slowik, Jay Gates; Bianchi, Federico; Yli-Juuti, Taina; Lehtipalo, Katrianne; Rondo, Linda; Breitenlechner, Martin; Kupc, Agnieszka; Almeida, João; Amorim, Antonio; Dunne, Eimear M.; Downard, Andrew J.; Ehrhart, Sebastian; Franchin, Alessandro; Kajos, Maija K.; Kirkby, Jasper; Kürten, Andreas; Nieminen, Tuomo; Makhmutov, Vladimir; Mathot, Serge; Miettinen, Pasi; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Santos, Filipe D.; Schallhart, Simon; Sipilä, Mikko; Stozhkov, Yuri; Tomé, Antonio; Vaattovaara, Petri; Wimmer, Daniela; Prévôt, André; Dommen, Josef; Donahue, Neil M.; Flagan, Richard C.; Viisanen, Yrjö; Weingartner, Ernest; Riipinen, Ilona; Hansel, Armin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R.; Baltensperger, Urs; Wex, Heike; Stratmann, Frank; Laaksonen, Ari; DeMott, Paul J.; O'Dowd, Colin D. [in: Nucleation and atmospheric aerosols]04B - Beitrag Konferenzschrift
- PublikationEvolution of particle composition in CLOUD nucleation experiments(Copernicus, 2013) Keskinen, Helmi; Virtanen, Annele; Joutsensaari, Jorma; Tsagkogeorgas, Georgios; Duplissy, Jonathan; Schobesberger, Siegfried; Gysel, Martin; Riccobono, Francesco; Slowik, Jay Gates; Bianchi, Federico; Yli-Juuti, Taina; Lehtipalo, Katrianne; Rondo, Linda; Breitenlechner, Martin; Kupc, Agnieszka; Almeida, João; Amorim, Antonio; Dunne, Eimear M.; Downard, Andrew J.; Ehrhart, Sebastian; Franchin, Alessandro; Kajos, Maija K.; Kirkby, Jasper; Kürten, Andreas; Nieminen, Tuomo; Makhmutov, Vladimir; Mathot, Serge; Miettinen, Pasi; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Santos, Felipe D.; Schallhart, Simon; Sipilä, Mikko; Stozhkov, Yuri; Tomé, Antonio; Vaattovaara, Petri; Wimmer, Daniela; Prévôt, André; Dommen, Josef; Donahue, Neil M.; Flagan, Richard C.; Weingartner, Ernest; Viisanen, Yrjö; Riipinen, Ilona; Hansel, Armin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R.; Baltensperger, Urs; Wex, Heike; Stratmann, Frank; Laaksonen, Ari [in: Atmospheric Chemistry and Physics]Sulphuric acid, ammonia, amines, and oxidised organics play a crucial role in nanoparticle formation in the atmosphere. In this study, we investigate the composition of nucleated nanoparticles formed from these compounds in the CLOUD (Cosmics Leaving Outdoor Droplets) chamber experiments at CERN (Centre européen pour la recherche nucléaire). The investigation was carried out via analysis of the particle hygroscopicity, ethanol affinity, oxidation state, and ion composition. Hygroscopicity was studied by a hygroscopic tandem differential mobility analyser and a cloud condensation nuclei counter, ethanol affinity by an organic differential mobility analyser and particle oxidation level by a high-resolution time-of-flight aerosol mass spectrometer. The ion composition was studied by an atmospheric pressure interface time-of-flight mass spectrometer. The volume fraction of the organics in the particles during their growth from sizes of a few nanometers to tens of nanometers was derived from measured hygroscopicity assuming the Zdanovskii–Stokes–Robinson relationship, and compared to values gained from the spectrometers. The ZSR-relationship was also applied to obtain the measured ethanol affinities during the particle growth, which were used to derive the volume fractions of sulphuric acid and the other inorganics (e.g. ammonium salts). In the presence of sulphuric acid and ammonia, particles with a mobility diameter of 150 nm were chemically neutralised to ammonium sulphate. In the presence of oxidation products of pinanediol, the organic volume fraction of freshly nucleated particles increased from 0.4 to ~0.9, with an increase in diameter from 2 to 63 nm. Conversely, the sulphuric acid volume fraction decreased from 0.6 to 0.1 when the particle diameter increased from 2 to 50 nm. The results provide information on the composition of nucleated aerosol particles during their growth in the presence of various combinations of sulphuric acid, ammonia, dimethylamine and organic oxidation products.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationMolecular understanding of sulphuric acid–amine particle nucleation in the atmosphere(Springer, 2013) Almeida, João; Schobesberger, Siegfried; Kürten, Andreas; Ortega, Ismael K.; Kupiainen-Määttä, Oona; Praplan, Arnaud P.; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M.; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N.; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J.; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D.; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H.; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E.; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S.; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Worsnop, Douglas R.; Vehkamäki, Hanna; Kirkby, Jasper [in: Nature]01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationNew particle formation in the free troposphere. A question of chemistry and timing(American Association for the Advancement of Science, 2016) Bianchi, Federico; Tröstl, Jasmin; Junninen, Heikki; Frege, Carla; Henne, Stephan; Hoyle, Christopher R.; Molteni, Ugo; Herrmann, Erik; Adamov, Alexey; Bukowiecki, Nicolas; Chen, Xuemeng; Duplissy, Jonathan; Gysel, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kontkanen, Jenni; Kürten, Andreas; Manninen, Hanna E.; Münch, Steffen; Peräkylä, Otso; Petäjä, Tuukka; Rondo, Linda; Williamson, Christina; Weingartner, Ernest; Curtius, Joachim; Worsnop, Douglas R.; Kulmala, Markku; Dommen, Josef; Baltensperger, Urs [in: Science]From neutral to new Many of the particles in the troposphere are formed in situ, but what fraction of all tropospheric particles do they constitute and how exactly are they made? Bianchi et al report results from a high-altitude research station. Roughly half of the particles were newly formed by the condensation of highly oxygenated multifunctional compounds. A combination of laboratory results, field measurements, and model calculations revealed that neutral nucleation is more than 10 times faster than ion-induced nucleation, that particle growth rates are size-dependent, and that new particle formation occurs during a limited time window.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationOxidation products of biogenic emissions contribute to nucleation of atmospheric particles(American Association for the Advancement of Science, 2014) Riccobono, Francesco; Schobesberger, Siegfried; Scott, Catherine E.; Dommen, Josef; Ortega, Ismael K.; Rondo, Linda; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Downard, Andrew; Dunne, Eimear M.; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Hansel, Armin; Junninen, Heikki; Kajos, Maija; Keskinen, Helmi; Kupc, Agnieszka; Kürten, Andreas; Kvashin, Alexander N.; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Nieminen, Tuomo; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P.; Santos, Filipe D.; Schallhart, Simon; Seinfeld, John H.; Sipilä, Mikko; Spracklen, Dominick V.; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjö; Vrtala, Aron; Wagner, Paul E.; Weingartner, Ernest; Wex, Heike; Wimmer, Daniela; Carslaw, Kenneth S.; Curtius, Joachim; Donahue, Neil M.; Kirkby, Jasper; Kulmala, Markku; Worsnop, Douglas R.; Baltensperger, Urs [in: Science]Out of the Air New-particle formation from gaseous precursors in the atmosphere is a complex and poorly understood process with importance in atmospheric chemistry and climate. Laboratory studies have had trouble reproducing the particle formation rates that must occur in the natural world. Riccobono et al. used the CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN to recreate a realistic atmospheric environment. Sulfuric acid and oxidized organic vapors in typical natural concentrations caused particle nucleation at similar rates to those observed in the lower atmosphere.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationParticle nucleation events at the high Alpine station Jungfraujoch(AIP Publishing, 24.05.2013) Bianchi, Federico; Junninen, Heikki; Tröstl, Jasmin; Duplissy, Jonathan; Rondo, Linda; Simon, Mario; Kürten, Andreas; Adamov, Alexey; Curtius, Joachim; Dommen, Josef; Weingartner, Ernest; Worsnop, Douglas R.; Kulmala, Markku; Baltensperger, Urs; DeMott, Paul J.; O´Dowd Colin D. [in: Nucleation and atmospheric aerosols]04B - Beitrag Konferenzschrift
- PublikationReduced anthropogenic aerosol radiative forcing caused by biogenic new particle formation(National Academy of Sciences, 2016) Gordon, Hamish; Sengupta, Kamalika; Rap, Alexandru; Duplissy, Jonathan; Frege, Carla; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K.; Wagner, Robert; Dunne, Eimear M.; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill S.; Dias, Antonio; Ehrhart, Sebastian; Fischer, Lukas; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Monks, Sarah A.; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P.; Pringle, Kirsty J.; Richards, Nigel A. D.; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E.; Seinfeld, John H.; Sharma, Sangeeta; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander Lucas; Wagner, Andrea C.; Wagner, Paul E.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M.; Worsnop, Douglas R.; Baltensperger, Urs; Kulmala, Markku; Curtius, Joachim; Carslaw, Kenneth S. [in: Proceedings of the National Academy of Sciences]A mechanism for the formation of atmospheric aerosols via the gas to particle conversion of highly oxidized organic molecules is found to be the dominant aerosol formation process in the preindustrial boundary layer over land. The inclusion of this process in a global aerosol model raises baseline preindustrial aerosol concentrations and could lead to a reduction of 27% in estimates of anthropogenic aerosol radiative forcing.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationRole of organics in particle nucleation. From the lab to global model(AIP Publishing, 2013) Dommen, Josef; Riccobono, Francesco; Schobesberger, Siegfried; Bianchi, Federico; Scott, Catherine; Ortega, Ismael K.; Rondo, Linda; Breitenlechner, Martin; Junninen, Heikki; Donahue, Neil M.; Kürten, Andreas; Praplan, Arnaud; Weingartner, Ernest; Hansel, Armin; Curtius, Joachim; Kirkby, Jasper; Kulmala, Markku; Carslaw, Kenneth S.; Worsnop, Douglas R.; Baltensperger, Urs; DeMott, Paul J.; O´Dowd Colin D. [in: Nucleation and atmospheric aerosols]04B - Beitrag Konferenzschrift
- PublikationThe regional aerosol-climate model REMO-HAM(Copernicus, 01.11.2012) Pietikäinen, Joni-Pekka; O'Donnell, Denis; Teichmann, Christopher; Karstens, Ute; Pfeifer, Samuel; Kazil, Jan; Podzun, Ralf; Fiedler, Susann; Kokkola, Harri; Birmili, Wolfram; O'Dowd, Colin D.; Baltensperger, Urs; Weingartner, Ernest; Gehrig, Robert; Spindler, Gerald; Kulmala, Markku; Feichter, Johann; Jacob, Daniela; Laaksonen, Aatto [in: Geoscientific Model Development]REMO-HAM is a new regional aerosol-climate model. It is based on the REMO regional climate model and includes most of the major aerosol processes. The structure for aerosol is similar to the global aerosol-climate model ECHAM5-HAM, for example the aerosol module HAM is coupled with a two-moment stratiform cloud scheme. On the other hand, REMO-HAM does not include an online coupled aerosol-radiation nor a secondary organic aerosol module. In this work, we evaluate the model and compare the results against ECHAM5-HAM and measurements. Four different measurement sites were chosen for the comparison of total number concentrations, size distributions and gas phase sulfur dioxide concentrations: Hyytiälä in Finland, Melpitz in Germany, Mace Head in Ireland and Jungfraujoch in Switzerland. REMO-HAM is run with two different resolutions: 50 × 50 km2 and 10 × 10 km2. Based on our simulations, REMO-HAM is in reasonable agreement with the measured values. The differences in the total number concentrations between REMO-HAM and ECHAM5-HAM can be mainly explained by the difference in the nucleation mode. Since we did not use activation nor kinetic nucleation for the boundary layer, the total number concentrations are somewhat underestimated. From the meteorological point of view, REMO-HAM represents the precipitation fields and 2 m temperature profile very well compared to measurement. Overall, we show that REMO-HAM is a functional aerosol-climate model, which will be used in further studies.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationThe role of low-volatility organic compounds in initial particle growth in the atmosphere(Springer, 2016) Tröstl, Jasmin; Chuang, Wayne K.; Gordon, Hamish; Heinritzi, Martin; Yan, Chao; Molteni, Ugo; Ahlm, Lars; Frege, Carla; Bianchi, Federico; Wagner, Robert; Simon, Mario; Lehtipalo, Katrianne; Williamson, Christina; Craven, Jill S.; Duplissy, Jonathan; Adamov, Alexey; Almeida, Joao; Bernhammer, Anne-Kathrin; Breitenlechner, Martin; Brilke, Sophia; Dias, Antònio; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Gysel, Martin; Hansel, Armin; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lawler, Michael; Leiminger, Markus; Mathot, Serge; Möhler, Ottmar; Nieminen, Tuomo; Onnela, Antti; Petäjä, Tuukka; Piel, Felix M.; Miettinen, Pasi; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Sengupta, Kamalika; Sipilä, Mikko; Smith, James N.; Steiner, Gerhard; Tomè, Antònio; Virtanen, Annele; Wagner, Andrea C.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Carslaw, Kenneth S.; Curtius, Joachim; Dommen, Josef; Kirkby, Jasper; Kulmala, Markku; Riipinen, Ilona; Worsnop, Douglas R.; Donahue, Neil M.; Baltensperger, Urs [in: Nature]About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst of new particles near midday1. Atmospheric observations show that the growth rate of new particles often accelerates when the diameter of the particles is between one and ten nanometres2,3. In this critical size range, new particles are most likely to be lost by coagulation with pre-existing particles4, thereby failing to form new cloud condensation nuclei that are typically 50 to 100 nanometres across. Sulfuric acid vapour is often involved in nucleation but is too scarce to explain most subsequent growth5,6, leaving organic vapours as the most plausible alternative, at least in the planetary boundary layer7,8,9,10. Although recent studies11,12,13 predict that low-volatility organic vapours contribute during initial growth, direct evidence has been lacking. The accelerating growth may result from increased photolytic production of condensable organic species in the afternoon2, and the presence of a possible Kelvin (curvature) effect, which inhibits organic vapour condensation on the smallest particles (the nano-Köhler theory)2,14, has so far remained ambiguous. Here we present experiments performed in a large chamber under atmospheric conditions that investigate the role of organic vapours in the initial growth of nucleated organic particles in the absence of inorganic acids and bases such as sulfuric acid or ammonia and amines, respectively. Using data from the same set of experiments, it has been shown15 that organic vapours alone can drive nucleation. We focus on the growth of nucleated particles and find that the organic vapours that drive initial growth have extremely low volatilities (saturation concentration less than 10−4.5 micrograms per cubic metre). As the particles increase in size and the Kelvin barrier falls, subsequent growth is primarily due to more abundant organic vapours of slightly higher volatility (saturation concentrations of 10−4.5 to 10−0.5 micrograms per cubic metre). We present a particle growth model that quantitatively reproduces our measurements. Furthermore, we implement a parameterization of the first steps of growth in a global aerosol model and find that concentrations of atmospheric cloud concentration nuclei can change substantially in response, that is, by up to 50 per cent in comparison with previously assumed growth rate parameterizations.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationVariations in tropospheric submicron particle size distributions across the European continent 2008–2009(Copernicus, 2014) Beddows, David; Dall'Osto, Manuel; Harrison, Roy; Kulmala, Markku; Asmi, Ari; Wiedensohler, Alfred; Laj, Paolo; Fjaeraa, Ann Mari; Sellegri, Karine; Birmili, Wolfram; Bukowiecki, Nicolas; Weingartner, Ernest; Baltensperger, Urs; Zdimal, Vladimir; Zikova, Nadezda; Putaud, Jean-Philippe; Marinoni, Angela; Tunved, Peter; Hansson, Hans-Christen; Fiebig, Markus; Kivekäs, Niku; Swietlicki, Erik; Lihavainen, Heikki; Asmi, Eija; Ulevicius, Vidmantas; Aalto, P. P.; Mihalopoulos, Nikolaos; Kalivitis, Nikos; Kalapov, Ivo; Kiss, Gyula; de Leeuw, Gerrit; Henzing, Bas; O'Dowd, Colin; Jennings, Stephen G.; Flentje, Harald; Meinhardt, Frank; Ries, Ludwig; Denier van der Gon, Hugo; Visschedijk, Antoon [in: Atmospheric Chemistry and Physics]Cluster~analysis of particle number size distributions from~background sites across Europe~is presented. This generated a total of nine clusters of particle size distributions which could be further combined into two main groups, namely: a south-to-north category (four clusters) and a west-to-east category (five clusters). The first group was identified as most frequently being detected inside and around northern Germany and neighbouring countries, showing clear evidence of local afternoon nucleation and growth events that could be linked to movement of air masses from south to north arriving ultimately at the Arctic contributing to Arctic haze.~The second group of particle size spectra proved to have narrower size distributions and collectively showed a dependence of modal diameter upon the longitude of the site (west to east) at which they were most frequently detected.~These clusters indicated regional nucleation (at the coastal sites) growing to larger modes further inland. The apparent growth rate of the modal diameter was around 0.6–0.9 nm h−1. Four specific air mass back-trajectories were successively taken as case studies to examine in real time the evolution of aerosol size distributions across Europe. ~While aerosol growth processes can be observed as aerosol traverses Europe, the processes are often obscured by the addition of aerosol by emissions en route. This study revealed that some of the 24 stations exhibit more complex behaviour than others, especially when impacted by local sources or a variety of different air masses. Overall, the aerosol size distribution clustering analysis greatly simplifies the complex data set and allows a description of aerosol aging processes, which reflects the longer-term average development of particle number size distributions as air masses advect across Europe.01A - Beitrag in wissenschaftlicher Zeitschrift