Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 14, 2020 | Supplemental Material + Published
Journal Article Open

Rapid growth of new atmospheric particles by nitric acid and ammonia condensation


A list of authors and their affiliations appears at the end of the paper New-particle formation is a major contributor to urban smog, but how it occurs in cities is often puzzling. If the growth rates of urban particles are similar to those found in cleaner environments (1–10 nanometres per hour), then existing understanding suggests that new urban particles should be rapidly scavenged by the high concentration of pre-existing particles. Here we show, through experiments performed under atmospheric conditions in the CLOUD chamber at CERN, that below about +5 degrees Celsius, nitric acid and ammonia vapours can condense onto freshly nucleated particles as small as a few nanometres in diameter. Moreover, when it is cold enough (below −15 degrees Celsius), nitric acid and ammonia can nucleate directly through an acid–base stabilization mechanism to form ammonium nitrate particles. Given that these vapours are often one thousand times more abundant than sulfuric acid, the resulting particle growth rates can be extremely high, reaching well above 100 nanometres per hour. However, these high growth rates require the gas-particle ammonium nitrate system to be out of equilibrium in order to sustain gas-phase supersaturations. In view of the strong temperature dependence that we measure for the gas-phase supersaturations, we expect such transient conditions to occur in inhomogeneous urban settings, especially in wintertime, driven by vertical mixing and by strong local sources such as traffic. Even though rapid growth from nitric acid and ammonia condensation may last for only a few minutes, it is nonetheless fast enough to shepherd freshly nucleated particles through the smallest size range where they are most vulnerable to scavenging loss, thus greatly increasing their survival probability. We also expect nitric acid and ammonia nucleation and rapid growth to be important in the relatively clean and cold upper free troposphere, where ammonia can be convected from the continental boundary layer and nitric acid is abundant from electrical storms.

Additional Information

© 2020 Springer Nature Limited. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 26 September 2019; Accepted 17 March 2020; Published 13 May 2020. We thank the European Organization for Nuclear Research (CERN) for supporting CLOUD with technical and financial resources and for providing a particle beam from the CERN Proton Synchrotron. This research has received funding from the US National Science Foundation (NSF; grant numbers AGS1602086, AGS1801329 and AGS-1801280); a NASA graduate fellowship (grant number NASA-NNX16AP36H); a Carnegie Mellon University Scott Institute Visiting Fellows grant; the Swiss National Science Foundation (grant numbers 200021_169090, 200020_172602 and 20FI20_172622); the European Community (EC) Seventh Framework Programme and the European Union (EU) H2020 programme (Marie Skłodowska Curie ITN CLOUD-TRAIN grant number 316662 and CLOUD-MOTION grant number 764991); a European Research Council (ERC) Advanced Grant (number ATM-GP 227463); an ERC Consolidator Grant (NANODYNAMITE 616075); an ERC Starting Grant (GASPARCON 714621), the Academy of Finland (grants 306853, 296628, 316114 and 299544); the Academy of Finland Center of Excellence programme (grant 307331); the German Federal Ministry of Education and Research (CLOUD-12 number 01LK1222A and CLOUD-16 number 01LK1601A); the Knut and Alice Wallenberg Foundation Wallenberg Academy Fellow project AtmoRemove (grant number 2015.0162); the Austrian Science Fund (grant number P 27295-N20); the Portuguese Foundation for Science and Technology (grant number CERN/FIS-COM/0014/2017); and the Presidium of the Russian Academy of Sciences ('High energy physics and neutrino astrophysics' 2015). The FIGAERO-CIMS was supported by a Major Research Instrumentation (MRI) grant for the US NSF (AGS-1531284), and by the Wallace Research Foundation. We thank H. Cawley for producing Fig. 4a. Data availability: The full dataset shown in the figures and tables is publicly available(58). All data shown in the figures and tables and additional raw data are available upon request from the corresponding author. Source data for Figs. 1–4 and Extended Data Figs. 1–7 are provided with the paper. Code availability: Codes for the MABNAG and nano-Köhler simulations and for conducting the analysis presented here can be obtained upon request from the corresponding author. Author Contributions: M.W., R.M., J. Dommen, U.B., J. Kirkby, I.E-H. and N.M.D. planned the experiments. M.W., W.K., R.M., X-C.H., D.C., J.P., A.K., H.E.M., S.A., A.B., S. Bräkling, S. Brilke, L.C.M., B.C., L-P.D.M., J. Duplissy, H.F., L.G.C., M.G., R.G., A. Hansel, V.H., J.K., K.L., H.L., C.P.L., V.M., G.M., S.M., B.M., T.M., A.O., E.P., T.P., M.P., V.P., M.R., B.R., W.S., J.S., M. Simon, M. Sipilä, G.S., D.S., Y.J.T., A.T., R.V., A.C.W., D.S.W., Y. Wang, S.K.W., P.M.W., P.J.W., Y. Wu, Q.Y., M.Z.-W., X.Z., J. Kirkby, I.E.-H. and R.C.F. prepared the CLOUD facility or measuring instruments. M.W., W.K., R.M., X.-C.H., D.C., J.P., L.D., H.E.M., S.A., A.A., R.B., A.B., D.M.B., B.B., S. Bräkling, S. Brilke, R.C., H.F., L.G.C., M.G., V.H., J.S., J. Duplissy, H.L., M.L., C.P.L., V.M., G.M., R.L.M., B.M., T.M., E.P., V.P., A.R., M.R., B.R., W.S., M. Simon, G.S., D.S., Y.J.T., A.T., A.C.W., D.S.W., Y. Wang, S.K.W., P.M.W., P.J.W., Y. Wu, M.X., M.Z.-W., X.Z., J. Kirkby and I.E.-H. collected the data. M.W., W.K., R.M., X.-C.H., D.C., J.P., A. Heitto, J. Kontkanen, L.D., A.K., T.Y.-J., H.E.M., S.A., L.G.C., J.S., W.S., M. Simon, D.S., D.S.W., S.K.W., P.M.W., I.E.-H., R.C.F. and N.M.D. analysed the data. M.W., W.K., R.M., X.-C.H., D.C., A. Heitto, J. Kontkanen, T.Y.-J., H.E.M., D.M.B., H.L., D.S., R.V., M.X., I.R., J. Dommen, J.C., U.B., M.K., D.R.W., J. Kirkby, J.H.S., I.E.-H., R.C.F. and N.M.D. contributed to the scientific discussion. M.W., W.K., R.M., X.-C.H., D.C., J.P., A. Heitto, J. Kontkanen, T.Y.-J., I.R., J. Dommen, U.B., M.K., D.R.W., J. Kirkby, J.H.S., I.E.-H., R.C.F. and N.M.D. wrote the manuscript. The authors declare no competing interests. Peer review information: Nature thanks Hugh Coe and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Attached Files

Published - s41586-020-2270-4.pdf

Supplemental Material - 41586_2020_2270_Fig10_ESM.webp

Supplemental Material - 41586_2020_2270_Fig11_ESM.webp

Supplemental Material - 41586_2020_2270_Fig5_ESM.webp

Supplemental Material - 41586_2020_2270_Fig6_ESM.webp

Supplemental Material - 41586_2020_2270_Fig7_ESM.webp

Supplemental Material - 41586_2020_2270_Fig8_ESM.webp

Supplemental Material - 41586_2020_2270_Fig9_ESM.webp

Supplemental Material - 41586_2020_2270_MOESM10_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM11_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM1_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM2_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM3_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM4_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM5_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM6_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM7_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM8_ESM.xlsx

Supplemental Material - 41586_2020_2270_MOESM9_ESM.xlsx


Files (12.8 MB)
Name Size Download all
82.4 kB Download
6.2 MB Download
66.7 kB Download
94.1 kB Download
131.7 kB Download
9.8 kB Download
13.5 kB Download
56.3 kB Download
115.2 kB Download
25.6 kB Download
40.7 kB Download
72.4 kB Download
131.7 kB Download
48.3 kB Download
177.1 kB Download
2.8 MB Preview Download
13.4 kB Download
2.5 MB Download
182.1 kB Download

Additional details

August 22, 2023
October 23, 2023