Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation

Autor(en)

Jasper Kirkby, Joachim Curtius, Jonathan Duplissy, Stéphanie Gagne, Luisa Ickes, Andreas Kürten, Agnieszka Kupc, A. Metzger, Linda Rondo, A. David, Josef Dommen, Mikael Ehn, Heikki Junninen, Ari Laaksonen, Katrianne Lehtipalo, J. M. Lima, Vladimir S. Makhmutov, Serge Mathot, Pierre Minginette, Sandra Mogo, Tuomo Nieminen, Antti Onnela, Tuukka Petäjä, John H. Seinfeld, Mikko Sipilä, Yurii Ivanovich Stozhkov, Frank Stratmann, Joonas Vanhanen, Yirö Viisanen, Aron Vrtala, Paul Wagner, Ernest Weingartner, Heike Wex, Paul Winkler, Ken Carslaw, Douglas R. Worsnop, Urs Baltensperger, Markku Kulmala

Abstrakt

Atmospheric aerosols exert an important influence on climate(1) through their effects on stratiform cloud albedo and lifetime(2) and the invigoration of convective storms(3). 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 vapours(4), although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small(5,6). 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 ammonia(7). 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 H(2)SO(4)-H(2)O can occur in the midtroposphere 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.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

European Organization for Nuclear Research (CERN), Johann Wolfgang Goethe-Universität Frankfurt am Main, University of Helsinki, Paul Scherrer Institute, Universidade de Lisboa, Lebedev Physical Institute, California Institute of Technology (Caltech), Leibniz-Institut für Troposphärenforschung, Finnish Meteorological Institute, University of Leeds, Aerodyne Res Inc, University of Eastern Finland

Journal

Nature

Band

476

Seiten

429-433

Anzahl der Seiten

5

ISSN

0028-0836

DOI

https://doi.org/10.1038/nature10343

Publikationsdatum

2011

Peer-reviewed

Ja

ÖFOS 2012

103034 Teilchenphysik

Sustainable Development Goals

SDG 13 – Maßnahmen zum Klimaschutz

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/d7ef8bd0-a4c0-411e-86d0-fbbc4bfb94fa