1 2 A Phenomenology of New Particle Formation (NPF) at 3 Thirteen European Sites 4 5 Dimitrios Bousiotis1, Francis D. Pope1, David C. Beddows1, 6 Manuel Dall’Osto2, Andreas Massling3, Jacob Klenø Nøjgaard3,4, 7 Claus Nordstrøm 3, Jarkko V. Niemi5, Harri Portin5, Tuukka Petäjä6, 8 Noemi Perez7, Andrés Alastuey7, Xavier Querol7, Giorgos Kouvarakis8, 9 Stergios Vratolis9, Konstantinos Eleftheriadis9, Alfred Wiedensohler10, 10 10 10 1† 10 Kay Weinhold , Maik Merkel , Thomas Tuch and Roy M. Harrison 11 12 1Division of Environmental Health and Risk Management 13 School of Geography, Earth and Environmental Sciences 14 University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom 15 16 2Institute of Marine Sciences 17 Passeig Marítim de la Barceloneta, 37-49, E-08003, Barcelona, Spain 18 19 3Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark 20 21 4The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark 22 23 5Helsinki Region Environmental Services Authority (HSY), 24 FI-00066 HSY, Helsinki, Finland 25 26 6Institute for Atmospheric and Earth System Research (INAR) / Physics, Faculty of Science, 27 University of Helsinki, Finland 28 29 7Institute of Environmental Assessment and Water Research (IDAEA - CSIC), 08034, 30 Barcelona, Spain 31 32 8Environmental Chemical Processes Laboratory (ECPL), Department of Chemistry, 33 University of Crete, 70013, Heraklion, Greece To whom correspondence should be addressed (Email:
[email protected]) †Also at: Department of Environmental Sciences / Center of Excellence in Environmental Studies, King Abdulaziz University, PO Box 80203, Jeddah, 21589, Saudi Arabia 1 34 35 9Environmental Radioactivity Laboratory, Institute of Nuclear and Radiological Science & 36 Technology, Energy & Safety, NCSR Demokritos, Athens, Greece 37 38 10Leibniz Institute for Tropospheric Research (TROPOS), 39 Permoserstr.