Auflistung nach Autor:in "Tsagkogeorgas, Georgios"

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Evolution 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 S.H.; 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.
04B - Beitrag Konferenzschrift
Evolution 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
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
Molecular 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
01A - Beitrag in wissenschaftlicher Zeitschrift
Oxidation 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
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
Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation
(Springer, 24.08.2011) Kirkby, Jasper; Curtius, Joachim; Almeida, João; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Franchin, Alessandro; Gagné, Stéphanie; Ickes, Luisa; Kürten, Andreas; Kupc, Agnieszka; Metzger, Axel; Riccobono, Francesco; Rondo, Linda; Schobesberger, Siegfried; Tsagkogeorgas, Georgios; Wimmer, Daniela; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Downard, Andrew; Ehn, Mikael; Flagan, Richard C.; Haider, Stefan; Hansel, Armin; Hauser, Daniel; Jud, Werner; Junninen, Heikki; Kreissl, Fabian; Kvashin, Alexander; Laaksonen, Ari; Lehtipalo, Katrianne; Lima, Jorge; Lovejoy, Edward R.; Makhmutov, Vladimir; Mathot, Serge; Mikkilä, Jyri; Minginette, Pierre; Mogo, Sandra; Nieminen, Tuomo; Onnela, Antti; Pereira, Paulo; Petäjä, Tuukka; Schnitzhofer, Ralf; Seinfeld, John H.; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Vanhanen, Joonas; Viisanen, Yrjo; Vrtala, Aron; Wagner, Paul E.; Walther, Hansueli; Weingartner, Ernest; Wex, Heike; Winkler, Paul M.; Carslaw, Kenneth S.; Worsnop, Douglas R.; Baltensperger, Urs; Kulmala, Markku
Atmospheric aerosols exert an important influence on climate through their effects on stratiform cloud albedo and lifetime and the invigoration of convective storms. Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small. Despite extensive research, fundamental questions remain about the nucleation rate of sulphuric acid particles and the mechanisms responsible, including the roles of galactic cosmic rays and other chemical species such as ammonia. Here we present the first results from the CLOUD experiment at CERN. We find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100–1,000-fold. Time-resolved molecular measurements reveal that nucleation proceeds by a base-stabilization mechanism involving the stepwise accretion of ammonia molecules. Ions increase the nucleation rate by an additional factor of between two and more than ten at ground-level galactic-cosmic-ray intensities, provided that the nucleation rate lies below the limiting ion-pair production rate. We find that ion-induced binary nucleation of H2SO4–H2O can occur in the mid-troposphere but is negligible in the boundary layer. However, even with the large enhancements in rate due to ammonia and ions, atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary-layer nucleation.
01A - Beitrag in wissenschaftlicher Zeitschrift