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1.
Can Highly Oxidized Organics Contribute to Atmospheric New Particle Formation? / Ortega, Ismael K (PhLAM, Villeneuve d'Ascq ; Carnegie Mellon U. (main)) ; Donahue, Neil M (Carnegie Mellon U. (main)) ; Kurtén, Theo (U. Helsinki (main)) ; Kulmala, Markku (Helsinki U.) ; Focsa, Cristian (PhLAM, Villeneuve d'Ascq) ; Vehkamäki, Hanna (Helsinki U.)
Highly oxidized organic molecules may play a critical role in new-particle formation within Earth’s atmosphere along with sulfuric acid, which has long been considered as a key compound in this process. Here we explore the interactions of these two partners, using quantum chemistry to find the formation free energies of heterodimers and trimers as well as the fastest evaporation rates of (2,2) tetramers. [...]
2015 - 7 p. - Published in : J. Phys. Chem. A 120 (2015) 1452-1458
2.
Influence of temperature on the molecular composition of ions and charged clusters during pure biogenic nucleation / Frege, Carla (PSI, Villigen) ; Ortega, Ismael K ; Rissanen, Matti P ; Praplan, Arnaud P ; Steiner, Gerhard ; Heinritzi, Martin ; Ahonen, Lauri ; Amorim, António ; Bernhammer, Anne-Kathrin ; Bianchi, Federico et al.
It was recently shown by the CERN CLOUD experiment that biogenic highly oxygenated molecules (HOMs) form particles under atmospheric conditions in the absence of sulfuric acid, where ions enhance the nucleation rate by 1–2 orders of magnitude. The biogenic HOMs were produced from ozonolysis of α-pinene at 5 °C. [...]
2018 - 15 p. - Published in : Atmos. Chem. Phys. 18 (2018) 65-79 Fulltext: PDF;
3.
Insight into Acid–Base Nucleation Experiments by Comparison of the Chemical Composition of Positive, Negative, and Neutral Clusters / Bianchi, Federico (PSI, Villigen) ; Praplan, Arnaud P (Helsinki U.) ; Sarnela, Nina (Helsinki U.) ; Dommen, Josef (PSI, Villigen) ; Kürten, Andreas (Goethe U., Frankfurt (main)) ; Ortega, Ismael K (Lille U.) ; Schobesberger, Siegfried (Helsinki U.) ; Junninen, Heikki (Helsinki U.) ; Simon, Mario (Goethe U., Frankfurt (main)) ; Tröstl, Jasmin (PSI, Villigen) et al.
We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. [...]
2014 - 10 p. - Published in : Environ. Sci. Technol. 48 (2014) 13675-13684 Fulltext: PDF;
4.
The effect of acid–base clustering and ions on the growth of atmospheric nano-particles / Lehtipalo, Katrianne (Helsinki U. ; PSI, Villigen) ; Rondo, Linda (Frankfurt U.) ; Kontkanen, Jenni (Helsinki U.) ; Schobesberger, Siegfried (Helsinki U. ; Washington U., Seattle) ; Jokinen, Tuija (Helsinki U.) ; Sarnela, Nina (Helsinki U.) ; Kürten, Andreas (Frankfurt U.) ; Ehrhart, Sebastian (Frankfurt U. ; CERN) ; Franchin, Alessandro (Helsinki U.) ; Nieminen, Tuomo (Helsinki U.) et al.
The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. [...]
2016 - Published in : Nature Commun. 7 (2016) 11594 Fulltext: PDF;
5.
Experimental particle formation rates spanning tropospheric sulfuric acid and ammonia abundances, ion production rates, and temperatures / Kürten, Andreas ; Bianchi, Federico ; Almeida, Joao (CERN) ; Kupiainen-Määttä, Oona ; Dunne, Eimear M. ; Duplissy, Jonathan (CERN) ; Williamson, Christina ; Barmet, Peter ; Breitenlechner, Martin ; Dommen, Josef et al.
Binary nucleation of sulfuric acid and water as well as ternary nucleation involving ammonia arethought to be the dominant processes responsible for new particle formation (NPF) in the cold temperaturesof the middle and upper troposphere. Ions are also thought to be important for particle nucleation inthese regions. [...]
2016 - 24 p. - Published in : J. Geophys. Res. Atmos. 121 (2016) 12,377-12,400
6.
Reduced anthropogenic aerosol radiative forcing caused by biogenic new particle formation / Gordon, Hamish (CERN) ; Sengupta, Kamalika (U. Leeds (main)) ; Rap, Alexandru (U. Leeds (main)) ; Duplissy, Jonathan (Helsinki Inst. of Phys.) ; Frege, Carla (PSI, Villigen) ; Williamson, Christina (Goethe U., Frankfurt (main) ; Colorado U., CIRES ; NCAR, Boulder) ; Heinritzi, Martin (Goethe U., Frankfurt (main)) ; Simon, Mario (Goethe U., Frankfurt (main)) ; Yan, Chao (Helsinki U.) ; Almeida, João (CERN ; Goethe U., Frankfurt (main)) et al.
2016 - Published in : Proc. Natl. Acad. Sci. U. S. A. 113 (2016) 12053-12058
7.
Ion-induced nucleation of pure biogenic particles / Kirkby, Jasper (Goethe U., Frankfurt (main) ; CERN) ; Duplissy, Jonathan (Helsinki U. ; Helsinki Inst. of Phys.) ; Sengupta, Kamalika (U. Leeds (main)) ; Frege, Carla (PSI, Villigen) ; Gordon, Hamish (CERN) ; Williamson, Christina (Goethe U., Frankfurt (main)) ; Heinritzi, Martin (Goethe U., Frankfurt (main) ; Innsbruck U.) ; Simon, Mario (Goethe U., Frankfurt (main)) ; Yan, Chao (Helsinki U.) ; Almeida, João (Goethe U., Frankfurt (main) ; CERN) et al.
Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. [...]
2016 - Published in : Nature 533 (2016) 521-526 NPG Open Access article: PDF;
8.
How do organic vapors contribute to new-particle formation? / Donahue, Neil M (Carnegie Mellon U. (main)) ; Ortega, Ismael K (Helsinki U.) ; Chuang, Wayne (Carnegie Mellon U. (main)) ; Riipinen, Ilona (Carnegie Mellon U. (main) ; Helsinki U. ; Stockholm U. (main)) ; Riccobono, Francesco (PSI, Villigen) ; Schobesberger, Siegfried (Helsinki U.) ; Dommen, Josef (PSI, Villigen) ; Baltensperger, Urs (PSI, Villigen) ; Kulmala, Markku (Helsinki U.) ; Worsnop, Douglas R (Helsinki U. ; Aerodyne Research, Billerica) et al.
Highly oxidised organic vapors can effectively stabilize sulphuric acid in heteronuclear clusters and drive new-particle formation. We present quantum chemical calculations of cluster stability, showing that multifunctional species can stabilize sulphuric acid and also present additional polar functional groups for subsequent cluster growth. [...]
2013 - Published in : Faraday Discuss. 165 (2013) 91-104
9.
Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules / Schobesberger, Siegfried (Helsinki U.) ; Junninen, Heikki (Helsinki U.) ; Bianchi, Federico (PSI, Villigen) ; Lönn, Gustaf (Helsinki U.) ; Ehn, Mikael (Helsinki U.) ; Lehtipalo, Katrianne (Helsinki U.) ; Dommen, Josef (PSI, Villigen) ; Ehrhart, Sebastian (Goethe U., Frankfurt (main)) ; Ortega, Ismael K (Helsinki U.) ; Franchin, Alessandro (Helsinki U.) et al.
Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. [...]
2013 - Published in : Proc. Natl. Acad. Sci. U.S.A. 110 (2013) 17223-17228
10.
Oxidation Products of Biogenic Emissions Contribute to Nucleation of Atmospheric Particles / Riccobono, Francesco (PSI, Villigen) ; Schobesberger, S (Helsinki U.) ; Baltensperger, Urs (PSI, Villigen) ; Worsnop, Douglas R (Helsinki U. ; Aerodyne Research, Billerica) ; Curtius, Joachim (Goethe U., Frankfurt (main)) ; Carslaw, Kenneth S (U. Leeds (main)) ; Wimmer, Daniela (Goethe U., Frankfurt (main)) ; Wex, Heike (TROPOS, Leibniz) ; Weingartner, Ernest (PSI, Villigen) ; Wagner, Paul E (Finnish Meteorological Inst.) et al.
Atmospheric new-particle formation affects climate and is one of the least understood atmospheric aerosol processes. The complexity and variability of the atmosphere has hindered elucidation of the fundamental mechanism of new-particle formation from gaseous precursors. [...]
2014 - Published in : Science 344 (2014) 717-721 Data S1: TXT; Data S2: TXT; Data S3: TXT; Data S4: TXT; Supplementary materials: PDF; External link: Free access (choose "reprint")

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