TY - JOUR A1 - Jokinen, Tuija A1 - Sipilä, Mikko A1 - Kontkanen, Jenni A1 - Vakkari, Ville A1 - Tisler, Priit A1 - Duplissy, Ella-Maria A1 - Junninen, Heikki A1 - Kangasluoma, Juha A1 - Manninen, Hanna Elina A1 - Petäjä, Tuukka A1 - Kulmala, Markku A1 - Worsnop, Douglas R. A1 - Kirkby, Jasper A1 - Virkkula, Aki A1 - Kerminen, Veli-Matti T1 - Ion-induced sulfuric acid–ammonia nucleation drives particle formation in coastal Antarctica T2 - Science advances N2 - Formation of new aerosol particles from trace gases is a major source of cloud condensation nuclei (CCN) in the global atmosphere, with potentially large effects on cloud optical properties and Earth’s radiative balance. Controlled laboratory experiments have resolved, in detail, the different nucleation pathways likely responsible for atmospheric new particle formation, yet very little is known from field studies about the molecular steps and compounds involved in different regions of the atmosphere. The scarcity of primary particle sources makes secondary aerosol formation particularly important in the Antarctic atmosphere. Here, we report on the observation of ion-induced nucleation of sulfuric acid and ammonia—a process experimentally investigated by the CERN CLOUD experiment—as a major source of secondary aerosol particles over coastal Antarctica. We further show that measured high sulfuric acid concentrations, exceeding 107 molecules cm−3, are sufficient to explain the observed new particle growth rates. Our findings show that ion-induced nucleation is the dominant particle formation mechanism, implying that galactic cosmic radiation plays a key role in new particle formation in the pristine Antarctic atmosphere. Y1 - 2018 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/48577 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-485779 SN - 2375-2548 N1 - opyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited. VL - 4 IS - 11, eaat9744 SP - 1 EP - 6 PB - Assoc. CY - Washington, DC [u. a.] ER -