Abstract

Atmospheric aerosols exert an important influence on climate1 through their effects on stratiform cloud albedo and lifetime2 and the invigoration of convective storms3. Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours4, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small5,6. Despite extensive research, fundamental questions remain about the nucleation rate of sulphuric acid particles and the mechanisms responsible, including the roles of galactic cosmic rays and other chemical species such as ammonia7. Here we present the first results from the CLOUD experiment at CERN. We find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100–1,000-fold. Time-resolved molecular measurements reveal that nucleation proceeds by a base-stabilization mechanism involving the stepwise accretion of ammonia molecules. Ions increase the nucleation rate by an additional factor of between two and more than ten at ground-level galactic-cosmic-ray intensities, provided that the nucleation rate lies below the limiting ion-pair production rate. We find that ion-induced binary nucleation of H2SO4–H2O can occur in the mid-troposphere but is negligible in the boundary layer. However, even with the large enhancements in rate due to ammonia and ions, atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary-layer nucleation.

  • Subscribe to Nature for full access:

    $199

    Subscribe

Additional access options:

Already a subscriber?  Log in  now or  Register  for online access.

References

  1. 1.

    IPCC. Climate Change 2007: the Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge Univ. Press, 2007)

  2. 2.

    & in Clouds in the Perturbed Climate System (eds & ) 319–338 (MIT Press, 2009)

  3. 3.

    et al. Flood or drought: how do aerosols affect precipitation? Science 321, 1309–1313 (2008)

  4. 4.

    , , , & Impact of nucleation on global CCN. Atmos. Chem. Phys. 9, 8601–8616 (2009)

  5. 5.

    et al. Contribution of particle formation to global cloud condensation nuclei concentrations. Geophys. Res. Lett. 35, L06808 10.1029/2007GL033038 (2008)

  6. 6.

    & Can cosmic rays affect cloud condensation nuclei by altering new particle formation rates? Geophys. Res. Lett. 36, L09820 10.1029/2009GL037946 (2009)

  7. 7.

    Getting to the critical nucleus of aerosol formation. Science 328, 1366–1367 (2010)

  8. 8.

    et al. Atmospheric nucleation: highlights of the EUCAARI project and future directions. Atmos. Chem. Phys. 10, 10829–10848 (2010)

  9. 9.

    et al. Sulphuric acid closure and contribution to nucleation mode particle growth. Atmos. Chem. Phys. 5, 863–878 (2005)

  10. 10.

    et al. Atmospheric nanoparticles formed from heterogeneous reactions of organics. Nature Geosci. 3, 238–242 (2010)

  11. 11.

    & Gaseous ammonia and ammonium ions in the free troposphere. Nature 321, 503–505 (1986)

  12. 12.

    & A preliminary study of the effect of ammonia on particle nucleation in the marine boundary layer. J. Geophys. Res. 100 (D4), 7147–7160 (1995)

  13. 13.

    , , & Laboratory studies of particle nucleation: initial results for H2SO4, H2O, and NH3 vapors. J. Geophys. Res. 104, 23709–23718 (1999)

  14. 14.

    et al. Atmospheric new particle formation enhanced by organic acids. Science 304, 1487–1490 (2004)

  15. 15.

    et al. Secondary aerosol formation from atmospheric reactions of aliphatic amines. Atmos. Chem. Phys. 7, 2313–2337 (2007)

  16. 16.

    et al. Laboratory study on new particle formation from the reaction OH + SO2: influence of experimental conditions, H2O vapour, NH3 and the amine tert-butylamine on the overall process. Atmos. Chem. Phys. 10, 7101–7116 (2010)

  17. 17.

    et al. Observations of aminium salts in atmospheric nanoparticles and possible climatic implications. Proc. Natl Acad. Sci. USA 107, 6634–6639 (2010)

  18. 18.

    et al. Formation of nanoparticles of blue haze enhanced by anthropogenic pollution. Proc. Natl Acad. Sci. USA 106, 17650–17654 (2009)

  19. 19.

    et al. Evidence for the role of organics in aerosol particle formation under atmospheric conditions. Proc. Natl Acad. Sci. USA 107, 6646–6651 (2010)

  20. 20.

    Multi-ion complexes in the stratosphere—implications for trace gases and aerosol. Nature 284, 610–611 (1980)

  21. 21.

    , & The role of ion-induced aerosol formation in the lower atmosphere. J. Aerosol Sci. 17, 466–470 (1986)

  22. 22.

    , & A new source of tropospheric aerosols: Ion–ion recombination. Geophys. Res. Lett. 25, 635–638 (1998)

  23. 23.

    , & Atmospheric ion-induced nucleation of sulfuric acid and water. J. Geophys. Res. 109, D08204 10.1029/2003JD004460 (2004)

  24. 24.

    & Laboratory study of cluster ions formation in H2SO4–H2O system: implications for threshold concentration of gaseous H2SO4 and ion-induced nucleation kinetics. Atmos. Environ. 41, 3740–3747 (2007)

  25. 25.

    , , , & Cosmic ray-induced aerosol-formation: first observational evidence from aircraft-based ion mass spectrometer measurements in the upper troposphere. Geophys. Res. Lett. 29, 1698–1701 (2002)

  26. 26.

    et al. Particle formation by ion nucleation in the upper troposphere and lower stratosphere. Science 301, 1886–1889 (2003)

  27. 27.

    & Variation of cosmic ray flux and global cloud coverage—a missing link in solar-climate relationships. J. Atmos. Sol. Terr. Phys. 59, 1225–1232 (1997)

  28. 28.

    Cosmic rays and climate. Surv. Geophys. 28, 333–375 (2007)

  29. 29.

    et al. The role of sulfuric acid in atmospheric nucleation. Science 327, 1243–1246 (2010)

  30. 30.

    & A semi-analytical method for calculating rates of new sulfate aerosol formation from the gas phase. Atmos. Chem. Phys. 7, 3447–3459 (2007)

  31. 31.

    , , & Amines are likely to enhance neutral and ion-induced sulfuric acid–water nucleation in the atmosphere more effectively than ammonia. Atmos. Chem. Phys. 8, 4095–4103 (2008)

  32. 32.

    , , & Dependence of nucleation rates on sulfuric acid vapor concentration in diverse atmospheric locations. J. Geophys. Res. 113, D10209 0.1029/2007JD009253 (2008)

  33. 33.

    et al. Connection between new particle formation and sulfuric acid at Hohenpeissenberg (Germany) including the influence of organic compounds. Boreal Envir. Res. 14, 616–629 (2009)

  34. 34.

    et al. Results from the CERN pilot CLOUD experiment. Atmos. Chem. Phys. 10, 1635–1647 (2010)

  35. 35.

    et al. A high-resolution mass spectrometer to measure atmospheric ion composition. Atmos. Meas. Tech. 3, 1039–1053 (2010)

  36. 36.

    , & Effect of working fluid on sub-2 nm particle detection with a laminar flow ultrafine condensation particle counter. Aerosol Sci. Technol. 43, 81–96 (2009)

  37. 37.

    et al. Particle size magnifier for nano-CN detection. Aerosol Sci. Technol. 45, 533–542 (2011)

  38. 38.

    , & Radial differential mobility analyzer for one nanometer particle classification. Aerosol Sci. Technol. 43, 53–59 (2009)

  39. 39.

    et al. Towards direct measurement of atmospheric nucleation. Science 318, 89–92 (2007)

  40. 40.

    , & High resolution PTR-TOF: quantification and formula confirmation of VOC in real time. J. Am. Soc. Mass Spectrom. 21, 1037–1044 (2010)

  41. 41.

    , & O2+ as reagent ion in the PTR-MS instrument: detection of gas-phase ammonia. Int. J. Mass Spectrom. 265, 382–387 (2007)

  42. 42.

    & Experimental thermodynamics of cluster ions composed of H2SO4 and H2O. 2. Measurements and ab initio structures of negative ions. J. Phys. Chem. A 107, 9812–9824 (2003)

  43. 43.

    & Analytical formulae connecting the ‘real’ and the ‘apparent’ nucleation rate and the nuclei number concentration for atmospheric nucleation events. J. Aerosol Sci. 33, 609–622 (2002)

  44. 44.

    & On the formation and growth of atmospheric nanoparticles. Atmos. Res. 90, 132–150 (2008)

Download references

Acknowledgements

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 J.-L. Agostini, S. Atieh, J. Baechler, D. Bloess, G. Bowden, A. Braem, T. Callamand, A. Castel, L.-P. De Menezes, G. Favre, L. Ferreira, L. Gatignon, D. Gregorio, M. Guinchard, E. Ivanova, F. Josa, I. Krasin, R. Kristic, A. Kuzmin, O. Maksumov, S. Mizin, R. Richter, R. Sitals, A. Vacca, R. Veenhof, A. Wasem and M. Wilhelmsson for their contributions to the experiment. This research has received funding from the EC Seventh Framework Programme under grant agreement no. 215072 (Marie Curie Initial Training Network, ‘CLOUD-ITN’) and ERC-Advanced Grant ‘ATMNUCLE’ no. 227463, the German Federal Ministry of Education and Research (project no. 01LK0902A), the Swiss National Science Foundation (project nos 206621_125025 and 206620_130527), the Academy of Finland Center of Excellence program (project no. 1118615), the Austrian Science Fund (FWF; project nos P19546 and L593), and the Russian Academy of Sciences and Russian Foundation for Basic Research (grant N08-02-91006-CERN).

Author information

Affiliations

  1. CERN, CH-1211 Geneva, Switzerland

    • Jasper Kirkby
    • , Jonathan Duplissy
    • , André David
    • , Stefan Haider
    • , Serge Mathot
    • , Pierre Minginette
    •  & Antti Onnela
  2. Goethe-University of Frankfurt, Institute for Atmospheric and Environmental Sciences, 60438 Frankfurt am Main, Germany

    • Joachim Curtius
    • , João Almeida
    • , Sebastian Ehrhart
    • , Luisa Ickes
    • , Andreas Kürten
    • , Linda Rondo
    • , Daniela Wimmer
    •  & Fabian Kreissl
  3. SIM, University of Lisbon and University of Beira Interior, 1749-016 Lisbon, Portugal

    • João Almeida
    • , Antonio Amorim
    • , Jorge Lima
    • , Sandra Mogo
    • , Paulo Pereira
    •  & Antonio Tomé
  4. University of Leeds, School of Earth and Environment, LS2-9JT Leeds, United Kingdom

    • Eimear Dunne
    •  & Kenneth S. Carslaw
  5. University of Helsinki, Department of Physics, FI-00014 Helsinki, Finland

    • Jonathan Duplissy
    • , Alessandro Franchin
    • , Stéphanie Gagné
    • , Siegfried Schobesberger
    • , Mikael Ehn
    • , Heikki Junninen
    • , Katrianne Lehtipalo
    • , Jyri Mikkilä
    • , Tuomo Nieminen
    • , Tuukka Petäjä
    • , Mikko Sipilä
    • , Joonas Vanhanen
    • , Douglas R. Worsnop
    •  & Markku Kulmala
  6. Helsinki Institute of Physics, University of Helsinki, FI-00014 Helsinki, Finland

    • Jonathan Duplissy
    • , Stéphanie Gagné
    •  & Mikko Sipilä
  7. University of Vienna, Faculty of Physics, 1090 Vienna, Austria

    • Agnieszka Kupc
    • , Aron Vrtala
    • , Paul E. Wagner
    •  & Paul M. Winkler
  8. Ionicon Analytik GmbH and University of Innsbruck, Institute for Ion and Applied Physics, 6020 Innsbruck, Austria

    • Axel Metzger
    • , Martin Breitenlechner
    • , Armin Hansel
    • , Daniel Hauser
    • , Werner Jud
    •  & Ralf Schnitzhofer
  9. Paul Scherrer Institut, Laboratory of Atmospheric Chemistry, CH-5232 Villigen, Switzerland

    • Francesco Riccobono
    • , Federico Bianchi
    • , Josef Dommen
    • , Hansueli Walther
    • , Ernest Weingartner
    •  & Urs Baltensperger
  10. Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany

    • Georgios Tsagkogeorgas
    • , Frank Stratmann
    •  & Heike Wex
  11. University of Milan, Department of Inorganic, Metallorganic, and Analytical Chemistry, 20133 Milan, Italy

    • Federico Bianchi
  12. California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, California 91125, USA

    • Andrew Downard
    • , Richard C. Flagan
    •  & John H. Seinfeld
  13. Lebedev Physical Institute, Solar and Cosmic Ray Research Laboratory, 119991 Moscow, Russia

    • Alexander Kvashin
    • , Vladimir Makhmutov
    •  & Yuri Stozhkov
  14. University of Eastern Finland, FI-70211 Kuopio, Finland

    • Ari Laaksonen
  15. NOAA Earth System Research Laboratory, Boulder, Colorado 80305, USA

    • Edward R. Lovejoy
  16. Finnish Meteorological Institute, FI-00101 Helsinki, Finland

    • Yrjo Viisanen
  17. Aerodyne Research Inc., Billerica, Massachusetts 01821, USA

    • Douglas R. Worsnop

Authors

  1. Search for Jasper Kirkby in:

  2. Search for Joachim Curtius in:

  3. Search for João Almeida in:

  4. Search for Eimear Dunne in:

  5. Search for Jonathan Duplissy in:

  6. Search for Sebastian Ehrhart in:

  7. Search for Alessandro Franchin in:

  8. Search for Stéphanie Gagné in:

  9. Search for Luisa Ickes in:

  10. Search for Andreas Kürten in:

  11. Search for Agnieszka Kupc in:

  12. Search for Axel Metzger in:

  13. Search for Francesco Riccobono in:

  14. Search for Linda Rondo in:

  15. Search for Siegfried Schobesberger in:

  16. Search for Georgios Tsagkogeorgas in:

  17. Search for Daniela Wimmer in:

  18. Search for Antonio Amorim in:

  19. Search for Federico Bianchi in:

  20. Search for Martin Breitenlechner in:

  21. Search for André David in:

  22. Search for Josef Dommen in:

  23. Search for Andrew Downard in:

  24. Search for Mikael Ehn in:

  25. Search for Richard C. Flagan in:

  26. Search for Stefan Haider in:

  27. Search for Armin Hansel in:

  28. Search for Daniel Hauser in:

  29. Search for Werner Jud in:

  30. Search for Heikki Junninen in:

  31. Search for Fabian Kreissl in:

  32. Search for Alexander Kvashin in:

  33. Search for Ari Laaksonen in:

  34. Search for Katrianne Lehtipalo in:

  35. Search for Jorge Lima in:

  36. Search for Edward R. Lovejoy in:

  37. Search for Vladimir Makhmutov in:

  38. Search for Serge Mathot in:

  39. Search for Jyri Mikkilä in:

  40. Search for Pierre Minginette in:

  41. Search for Sandra Mogo in:

  42. Search for Tuomo Nieminen in:

  43. Search for Antti Onnela in:

  44. Search for Paulo Pereira in:

  45. Search for Tuukka Petäjä in:

  46. Search for Ralf Schnitzhofer in:

  47. Search for John H. Seinfeld in:

  48. Search for Mikko Sipilä in:

  49. Search for Yuri Stozhkov in:

  50. Search for Frank Stratmann in:

  51. Search for Antonio Tomé in:

  52. Search for Joonas Vanhanen in:

  53. Search for Yrjo Viisanen in:

  54. Search for Aron Vrtala in:

  55. Search for Paul E. Wagner in:

  56. Search for Hansueli Walther in:

  57. Search for Ernest Weingartner in:

  58. Search for Heike Wex in:

  59. Search for Paul M. Winkler in:

  60. Search for Kenneth S. Carslaw in:

  61. Search for Douglas R. Worsnop in:

  62. Search for Urs Baltensperger in:

  63. Search for Markku Kulmala in:

Contributions

J.A. performed the nucleation rate analysis. S.S. conducted the APi-TOF analysis. J.A., F.B., M.B., A. Downard, E.D., J. Duplissy, S.E., A.F., S.G., D.H., L.I., W.J., J.K., F.K., A. Kürten, A. Kupc, K.L., V.M., A.M., T.N., F.R., L.R., R.S., S.S., Y.S., G.T. and D.W. conducted the data collection and analysis. J.A., K.S.C., J.C., E.D., S.E., L.I., E.R.L. and F.S. performed the modelling. J.K. wrote the manuscript. U.B., K.S.C., J.C., J.K., M.K., J.H.S. and D.R.W. did data interpretation and editing of the manuscript. All authors contributed to the development of the CLOUD facility and analysis instruments, and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Jasper Kirkby.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    The file contains Supplementary Text and Data, Supplementary References and Supplementary Figures 1-4 with legends.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nature10343

Rights and permissions

To obtain permission to re-use content from this article visit RightsLink.

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.