AMT Atmospheric Measurement Techniques AMT Atmos. Meas. Tech. 1867-8548 Copernicus Publications Göttingen, Germany 10.5194/amt-5-1869-2012 Soot reference materials for instrument calibration and intercomparisons: a workshop summary with recommendations Baumgardner D. 1 Popovicheva O. 2 Allan J. 3 Bernardoni V. 4 Cao J. 5 Cavalli F. 6 Cozic J. 7 Diapouli E. 8 Eleftheriadis K. 8 Genberg P. J. 9 Gonzalez C. 10 Gysel M. 11 John A. 12 Kirchstetter T. W. 13 Kuhlbusch T. A. J. 12 14 Laborde M. 11 Lack D. 15 16 Müller T. 17 Niessner R. 18 Petzold A. 19 Piazzalunga A. 20 Putaud J. P. 6 Schwarz J. 15 16 Sheridan P. 15 Subramanian R. 21 Swietlicki E. 9 Valli G. 4 Vecchi R. 4 Viana M. 22 Centro Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico Nuclear Physics, Moscow, State University, Moscow, Russia University of Manchester, Manchester, UK Department of Physics, Università degli Studi di Milano & National Institute of Nuclear Physics, Milan, Italy Institute of Earth Environment, Chinese Academy of Sciences, Xian, China European Commision – Joint Research Centre – Institute for Environment and Sustainability, Ispra, Italy Laboratory of Glaciology and Geophysics of the Environment, St Martin d'Hères Cedex, France E.R.L, Institute of Nuclear Technology & Radiation Protection, N.C.S.R. Demokritos, 15310, Attiki, Greece Div. of Nuclear Physics, Lund University, P.O. Box 118, 22100, Lund, Sweden National Institute of Standards and Technology, Gaithersburg, MD, USA Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, Villigen, Switzerland IUTA e.v., Air Quality & Sustainable Nanotechnology Unit, Duisburg, Germany Lawrence Berkeley National Laboratory, Berkeley, CA, USA King's College London, Environmental Research Group, London, UK Earth Systems Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA Leibniz Institute for Tropospheric Research, Leipzig, Germany Technische Universität, München, Germany Deutschen Zentrums für Luft- und Raumfahrt, Oberpfaffenhofen, Germany Department of Environmental and Territorial Sciences, University of Milan-Bicocca & Department of Inorganic, Metallorganic and Analytical Chemistry, Università degli Studi di Milano, Milan, Italy RTI, Research Triangle, NC, USA IDAEA-CSIC: Institute for Environmental Assessment and Water Research (IDǼA), Spanish Research Council – CSIC, Barcelona, Spain 02 08 2012 5 8 1869 1887 Copyright: © 2012 D. Baumgardner et al. 2012 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://amt.copernicus.org/articles/5/1869/2012/amt-5-1869-2012.html The full text article is available as a PDF file from https://amt.copernicus.org/articles/5/1869/2012/amt-5-1869-2012.pdf

Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure the properties of soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot. <br><Br> The current state of availability and practicability of soot standard reference materials (SRMs) was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of soot SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of users of the single-particle soot-photometer (SP2), an instrument using laser-induced incandescence, identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA) to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop, and subsequent, interactive discussions, produced a number of recommendations for the development of new SRMs, and their implementation, that would be suitable for the different soot measurement methods.

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