ACPD Atmospheric Chemistry and Physics Discussions ACPD Atmos. Chem. Phys. Discuss. 1680-7375 Göttingen, Germany 10.5194/acpd-12-24821-2012 Are black carbon and soot the same? Buseck P. R. 1 2 Adachi K. 1 2 3 Gelencsér A. 4 Tompa É. 4 Pósfai M. 4 School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85282, USA Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85282, USA Atmospheric Environment and Applied Meteorology Research Department, Meteorological Research Institute, Tsukuba, Ibaraki, Japan Department of Earth and Environmental Sciences, University of Pannonia, Veszprém, Hungary 21 09 2012 12 9 24821 24846 Copyright: © 2012 P. R. Buseck 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://acp.copernicus.org/preprints/12/24821/2012/acpd-12-24821-2012.html The full text article is available as a PDF file from https://acp.copernicus.org/preprints/12/24821/2012/acpd-12-24821-2012.pdf

The climate change and environmental literature, including that on aerosols, is replete with mention of black carbon (BC), but neither reliable samples nor standards exist. Thus, there is uncertainty about its exact nature. That confusion can be avoided if terms are defined and widely understood. Here we discuss an ambiguity between BC and soot and propose a more precise definition for soot as a specific material, which we call ns-soot, where "ns" refers to carbon nanospheres. We define ns-soot as particles that consist of nanospheres, typically with diameters < 100 nm, that possess distinct structures of concentrically wrapped, graphene-like layers of carbon and with grape-like (acinoform) morphologies. We additionally propose that, because of their importance for climate modeling and health issues, distinctions are made among bare, coated, and embedded ns-soot. BC, on the other hand, is not a well-defined material. We propose that the term should be restricted to light-absorbing refractory carbonaceous matter of uncertain character and that the uncertainty is stated explicitly.

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