Kim, J. and Flagan, R. C. (2016) Hygroscopicity of nanoparticles produced from homogeneous nucleation in the CLOUD experiments. Atmospheric Chemistry and Physics, 16 (1). pp. 293-304. ISSN 1680-7316. http://resolver.caltech.edu/CaltechAUTHORS:20160325-114445163
- Published Version
Creative Commons Attribution.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20160325-114445163
Sulfuric acid, amines and oxidized organics have been found to be important compounds in the nucleation and initial growth of atmospheric particles. Because of the challenges involved in determining the chemical composition of objects with very small mass, however, the properties of the freshly nucleated particles and the detailed pathways of their formation processes are still not clear. In this study, we focus on a challenging size range, i.e., particles that have grown to diameters of 10 and 15 nm following nucleation, and measure their water uptake. Water uptake is useful information for indirectly obtaining chemical composition of aerosol particles. We use a nanometer-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) at subsaturated conditions (ca. 90% relative humidity at 293 K) to measure the hygroscopicity of particles during the seventh Cosmics Leaving OUtdoor Droplets (CLOUD7) campaign performed at CERN in 2012. In CLOUD7, the hygroscopicity of nucleated nanoparticles was measured in the presence of sulfuric acid, sulfuric acid-dimethylamine, and sulfuric acid-organics derived from α-pinene oxidation. The hygroscopicity parameter κ decreased with increasing particle size, indicating decreasing acidity of particles. No clear effect of the sulfuric acid concentration on the hygroscopicity of 10 nm particles produced from sulfuric acid and dimethylamine was observed, whereas the hygroscopicity of 15 nm particles sharply decreased with decreasing sulfuric acid concentrations. In particular, when the concentration of sulfuric acid was 5:1 x 10^6 molecules cm^(-3) in the gas phase, and the dimethylamine mixing ratio was 11.8 ppt, the measured κ of 15 nm particles was 0.31 ± 0.01: close to the value reported for dimethylaminium sulfate (DMAS) (κ_(DMAS) ~0:28). Furthermore, the difference in κ between sulfuric acid and sulfuric acid-dimethylamine experiments increased with increasing particle size. The κ values of particles in the presence of sulfuric acid and organics were much smaller than those of particles in the presence of sulfuric acid and dimethylamine. This suggests that the organics produced from α-pinene ozonolysis play a significant role in particle growth even at 10 nm sizes.
|Additional Information:||© Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License. Published by Copernicus Publications on behalf of the European Geosciences Union. Received: 8 June 2015; Published in Atmos. Chem. Phys. Discuss.: 20 July 2015; Revised: 11 November 2015; Accepted: 17 December 2015; Published: 18 January 2016. We would like to 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, F. Josa, I. Krasin, R. Kristic, A. Laassiri, O. S. Maksumov, B. Marichy, H. Martinati, S. V. Mizin, R. Sitals, A. Wasem, and M. Wilhelmsson for their important contributions to the experiment. We thank the CSC Centre for Scientific Computing in Espoo, Finland, for computer time. This research has 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 Grant MOCAPAF no. 57360, ERC Consolidator Grant NANODYNAMITE no. 616075, ERC Advanced Grant ATMNUCLE no. 227463, and ERC Starting Grant “QAPPA” grant no. 335478); the German Federal Ministry of Education and Research (project nos. 01LK0902A and 01LK1222A); the Swiss National Science Foundation (project nos. 200020 135307, 200021 140663, 206021 144947/1, 20FI20 149002/1, and 200021 140663); the Academy of Finland Centre of Excellence program (project no. 1118615); the Academy of Finland (135054, 133872, 251427, 1389515, 139656, 139995, 137749, 141217, 141451, 2720541, 259005, 264989); the Finnish Funding Agency for Technology and Innovation; the Nessling Foundation; the Strategic Funding from University of Eastern Finland; the Austrian Science Fund (FWF; project no. P19546 and L59321); 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 Russian Foundation for Basic Research (grants 08-02-91006-CERN and 12-02-91522-CERN); the U.S. National Science Foundation (grants AGS1136479 and CHE1012293); a Davidow Grant to Caltech’s Global Environmental Science Program; Dreyfus Award EP-11-117; the French National Research Agency (ANR); the Nord-Pas de Calais; the European Funds for Regional Economic Development (FEDER, Labex-Cappa, ANR-11-LABX-0005-01); and the French Civil Aviation Office (MERMOSE).|
|Official Citation:||Kim, J., Ahlm, L., Yli-Juuti, T., Lawler, M., Keskinen, H., Tröstl, J., Schobesberger, S., Duplissy, J., Amorim, A., Bianchi, F., Donahue, N. M., Flagan, R. C., Hakala, J., Heinritzi, M., Jokinen, T., Kürten, A., Laaksonen, A., Lehtipalo, K., Miettinen, P., Petäjä, T., Rissanen, M. P., Rondo, L., Sengupta, K., Simon, M., Tomé, A., Williamson, C., Wimmer, D., Winkler, P. M., Ehrhart, S., Ye, P., Kirkby, J., Curtius, J., Baltensperger, U., Kulmala, M., Lehtinen, K. E. J., Smith, J. N., Riipinen, I., and Virtanen, A.: Hygroscopicity of nanoparticles produced from homogeneous nucleation in the CLOUD experiments, Atmos. Chem. Phys., 16, 293-304, doi:10.5194/acp-16-293-2016, 2016.|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Melissa Ray|
|Deposited On:||31 Mar 2016 00:47|
|Last Modified:||31 Mar 2016 00:47|
Repository Staff Only: item control page