A global analysis of climate-relevant aerosol properties retrieved from the network of GAW near-surface observatories
Authors: Laj Paolo , Bigi Alessandro , Rose Clémence , Andrews Elisabeth , Lund Myhre Cathrine , Collaud Coen Martine , Wiedensohler Alfred , Schultz Michael , Ogren John A. , Fiebig Markus , Gliß Jonas , Mortier Augustin , Pandolfi Marco , Petäjä Tuukka , Kim Sang-Woo , Aas Wenche , Putaud Jean-Phillipe , Mayol-Bracero Olga , Keywood Melita , Labrador Lorenzo , Aalto Pasi , Ahlberg Erik , Alados Arboledas Lucas , Alastuey Andrés , Andrade Marcos , Artíñano Begoña , Ausmeel Stina , Arsov Todor , Asmi Eija , Backman John , Baltensperger Urs , Bastian Susanne , Bath Olaf , Beukes Johan Paul , Brem Benjamin T. , Bukowiecki Nicolas , Conil Sébastien , Couret Cedric , Day Derek , Dayantolis Wan , Degorska Anna , Dos Santos Sebastiao Martins , Eleftheriadis Konstantinos , Fetfatzis Prodromos , Favez Olivier , Flentje Harald , Gini Maria I. , Gregorič Asta , Gysel-Beer Martin , Hallar Gannet A. , Hand Jenny , Hoffer Andras , Hueglin Christoph , Hooda Rakesh K. , Hyvärinen Antti , Kalapov Ivo , Kalivitis Nikos , Kasper-Giebl Anne , Kim Jeong Eun , Kouvarakis Giorgos , Kranjc Irena , Krejci Radovan , Kulmala Markku , Labuschagne Casper , Lee Hae-Jung , Lihavainen Heikki , Lin Neng-Huei , Löschau Gunter , Luoma Krista , Marinoni Angela , Meinhardt Frank , Merkel Maik , Metzger Jean-Marc , Mihalopoulos Nikolaos , Nguyen Nhat Anh , Ondracek Jakub , Peréz Noemi , Perrone Maria Rita , Petit Jean-Eudes , Picard David , Pichon Jean-Marc , Pont Véronique , Prats Natalia , Prenni Anthony , Reisen Fabienne , Romano Salvatore , Sellegri Karine , Sharma Sangeeta , Schauer Gerhard , Sheridan Patrick , Sherman James Patrick , Schütze Maik , Schwerin Andreas , Sohmer Ralf , Sorribas Mar , Steinbacher Martin , Sun Junying , Titos Gloria , Tokzko Barbara , Tuch Thomas , Tulet Pierre , Tunved Peter , Vakkari Ville , Velarde Fernando , Velasquez Patricio , Villani Paolo , Vratolis Sterios , Wang Sheng-Hsiang , Weinhold Kay , Weller Rolf , Yela Margarita , Yus-Diez Jesus , Zdimal Vladimir , Zieger Paul , Zikova Nadezda 
Published: February 2020

Abstract. Aerosol particles are essential constituents of the Earth’s atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence time resulting in a highly heterogeneous distribution in space and time. There is a clear need to document this variability at regional scale through observations involving, in particular, the in-situ near-surface segment of the atmospheric observations system. This paper will provide the widest effort so far to document variability of climate-relevant in-situ aerosol properties (namely wavelength dependent particle light scattering and absorption coefficients, particle number concentration and particle number size distribution) from all sites connected to the Global Atmosphere Watch network. High quality data from more than 90 stations worldwide have been collected and controlled for quality and are reported for a reference year in 2017, providing a very extended and robust view of the variability of these variables worldwide. The range of variability observed worldwide for light scattering and absorption coefficients, single scattering albedo and particle number concentration are presented together with preliminary information on their long-term trends and comparison with model simulation for the different stations. The scope of the present paper is also to provide the necessary suite of information including data provision procedures, quality control and analysis, data policy and usage of the ground-based aerosol measurements network. It delivers to users of the World Data Centre on Aerosol, the required confidence in data products in the form of a fully-characterized value chain, including uncertainty estimation and requirements for contributing to the global climate monitoring system.