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Molecular understanding of sulphuric acid–amine particle nucleation in the atmosphere

Almeida, João and Downard, Andrew J. and Flagan, Richard C. and Seinfeld, John H. (2013) Molecular understanding of sulphuric acid–amine particle nucleation in the atmosphere. Nature, 502 (7471). pp. 359-363. ISSN 0028-0836. PMCID PMC7449521. doi:10.1038/nature12663.

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Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere3. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates more than 1,000-fold compared with ammonia, sufficient to account for the particle formation rates observed in the atmosphere. Molecular analysis of the clusters reveals that the faster nucleation is explained by a base-stabilization mechanism involving acid–amine pairs, which strongly decrease evaporation. The ion-induced contribution is generally small, reflecting the high stability of sulphuric acid–dimethylamine clusters and indicating that galactic cosmic rays exert only a small influence on their formation, except at low overall formation rates. Our experimental measurements are well reproduced by a dynamical model based on quantum chemical calculations of binding energies of molecular clusters, without any fitted parameters. These results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation.

Item Type:Article
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URLURL TypeDescription CentralArticle
Flagan, Richard C.0000-0001-5690-770X
Seinfeld, John H.0000-0003-1344-4068
Additional Information:© 2013 Nature Publishing Group, a division of Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Received 4 March; accepted 17 September 2013; Published online 6 October 2013. We thank J.-L. Agostini, P. Carrie, L.-P. De Menezes, F. Josa, I. Krasin, R. Kristic, O.S. Maksumov, S.V. Mizin, R. Sitals, A. Wasem and M. Wilhelmsson for their contributions to the experiment, and D. Hanson and P. McMurry for discussions on their unpublished measurements of ambient gas-phase amines. We thank the CSC Centre for Scientific Computing in Espoo, Finland, for computer time, and J. Pierce and P. Paasonen for discussions. We thank CERN for supporting CLOUD with technical and financial resources, and for providing a particle beam from the CERN Proton Synchrotron. This research received funding from the EC Seventh Framework Programme (Marie Curie Initial Training Network ‘CLOUD-ITN’ no. 215072, MC-ITN ‘CLOUD-TRAIN’ no. 316662, ERC-Starting ‘MOCAPAF’ grant 57360 and ERC-Advanced ‘ATMNUCLE’ grant 227463), the German Federal Ministry of Education and Research (projects 01LK0902A and 01LK1222A), the Swiss National Science Foundation (projects 200020_135307 and 206620_130527), the Academy of Finland (Center of Excellence project 1118615), the Academy of Finland (135054, 133872, 251427, 139656, 139995, 137749, 141217 and 141451), the Finnish Funding Agency for Technology and Innovation, the Väisälä Foundation, the Nessling Foundation, the Austrian Science Fund (FWF; projects P19546 and L593), the Portuguese Foundation for Science and Technology (project CERN/FP/116387/2010), the Swedish Research Council, Vetenskapsrådet (grant 2011-5120), the Presidium of the Russian Academy of Sciences and Russian Foundation for Basic Research (grants 08-02-91006-CERN and 12-02-91522-CERN), and the US National Science Foundation (grants AGS1136479 and CHE1012293).
Funding AgencyGrant Number
Marie Curie Fellowship215072
Marie Curie Fellowship316662
European Research Council (ERC)MOCAPAF57360
European Research Council (ERC)ATMNUCLE 227463
German Federal Ministry of Education and Research01LK0902A
German Federal Ministry of Education and Research01LK1222A
Swiss National Science Foundation (SNSF)200020_135307
Swiss National Science Foundation (SNSF)206620_130527
Academy of Finland1118615
Academy of Finland135054
Academy of Finland133872
Academy of Finland251427
Academy of Finland139656
Academy of Finland139995
Academy of Finland137749
Academy of Finland141217
Academy of Finland141451
Finnish Funding Agency for Technology and InnovationUNSPECIFIED
Väisälä FoundationUNSPECIFIED
Nessling FoundationUNSPECIFIED
FWF der WissenfondsP19546
FWF der WissenfondsL593
Fundação para a Ciência e a Tecnologia (FCT)CERN/FP/116387/2010
Swedish Research CouncilUNSPECIFIED
Presidium of the Russian Academy of SciencesUNSPECIFIED
Russian Foundation for Basic Research08-02-91006-CERN
Russian Foundation for Basic Research12-02-91522-CERN
Subject Keywords:Atmospheric chemistry
Issue or Number:7471
PubMed Central ID:PMC7449521
Record Number:CaltechAUTHORS:20131115-115842493
Persistent URL:
Official Citation:Almeida, J., Schobesberger, S., Kürten, A. et al. Molecular understanding of sulphuric acid–amine particle nucleation in the atmosphere. Nature 502, 359–363 (2013).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:42500
Deposited On:19 Nov 2013 22:15
Last Modified:15 Feb 2022 18:48

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