Abstract
Fundamental questions remain about the origin of newly formed atmospheric aerosol particles because data from laboratory measurements have been insufficient to build global models. In contrast, gas-phase chemistry models have been based on laboratory kinetics measurements for decades. We built a global model of aerosol formation by using extensive laboratory measurements of rates of nucleation involving sulfuric acid, ammonia, ions, and organic compounds conducted in the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber. The simulations and a comparison with atmospheric observations show that nearly all nucleation throughout the present-day atmosphere involves ammonia or biogenic organic compounds, in addition to sulfuric acid. A considerable fraction of nucleation involves ions, but the relatively weak dependence on ion concentrations indicates that for the processes studied, variations in cosmic ray intensity do not appreciably affect climate through nucleation in the present-day atmosphere.
| Original language | English |
|---|---|
| Pages (from-to) | 1119-1124 |
| Number of pages | 6 |
| Journal | Science |
| Volume | 354 |
| Issue number | 6316 |
| DOIs | |
| Publication status | Published - 2 Dec 2016 |
| MoE publication type | A1 Journal article-refereed |
Funding
We thank CERN for supporting CLOUD with important technical and financial resources and for providing a particle beam from the CERN Proton Synchrotron. We also thank P. Carrie, L.-P. De Menezes, J. Dumollard, K. Ivanova, F. Josa, I. Krasin, R. Kristic, A. Laassiri, O. S. Maksumov, B. Marichy, H. Martinati, S. V. Mizin, R. Sitals, H. U. Walther, A. Wasem, and M. Wilhelmsson for their important contributions to the experiment. The computer modeling simulations were performed on ARC1 and ARC2, part of the highperformance computing facilities at the University of Leeds, UK. This work also made use of the POLARIS facility of the N8 High Performance Computing Centre of Excellence, provided and funded by the N8 consortium and the Engineering and Physical Sciences Research Council (grant no. EP/K000225/1). The Centre is coordinated by the Universities of Leeds and Manchester. This research has received funding from the European Commission Seventh Framework Programme [Marie Curie Initial Training Networks CLOUD-ITN (no. 215072) and CLOUD-TRAIN (no. 316662)]; European Research Council (ERC) Starting Grant no. 5736 [MOCAPAF (Role of Molecular Clusters in Atmospheric Particle Formation)] and ERC Advanced grant no. 227463 [ATMNUCLE (Atmospheric Nucleation: From Molecular to Global Scale)]; the German Federal Ministry of Education and Research (project nos. 01LK0902A and 01LK1222A); the Swiss National Science Foundation (project nos. 200020 135307 and 206620 141278); the Academy of Finland (Center of Excellence project no. 1118615 and other projects 135054, 133872, 251427, 139656, 139995, 137749, 141217, 141451, and 138951); the Finnish Funding Agency for Technology and Innovation; the V.is.l. Foundation; the Nessling Foundation; the Austrian Science Fund (FWF) (project no. J3198-N21); the Portuguese Foundation for Science and Technology (project no. CERN/FP/116387/2010); the Swedish Research Council; Vetenskapsrådet (grant 2011-5120); the Presidium of the Russian Academy of Sciences and the Russian Foundation for Basic Research (grants 08-02-91006-CERN and 12-02-91522-CERN); the U.S. National Science Foundation (grants AGS1136479, AGS1447056, AGC1439551, and CHE1012293); the U.S. Department of Energy (grant DE-SC0014469); the PEGASOS (Pan-European Gas-Aerosol-Climate Interaction Study) project funded by the European Commission under Framework Programme 7 (FP7-ENV- 2010-265148); the Davidow Foundation; and the Natural Environment Research Council project GASSP (Global Aerosol Synthesis and Science Project) under grant NE/J024252/1. We acknowledge financial support from the Royal Society Wolfson Merit Award. The nucleation rates used in our manuscript are available in the supplementary materials as a CSV file.