05490 IUPAC Gold Book - scattering cross-section 10.1351/goldbook.S05490 S05490 current 1 The scattering coefficient per particle (\(\frac{\rm{cm}^{2}}{\rm{particle}}\)); \[b_{\rm{scat}}=n\ \sigma _{\rm{scat}}\] where \(n\) is the number concentration of particles (\(\rm{particles cm}^{-3}\)) and \(\sigma _{\rm{scat}}\) is the scattering cross-section. \(b_{\rm{scat}}\), the scattering component of extinction due to gas and particles, is measured in the atmosphere using a nephelometer. For a homogeneous atmosphere it is related in theory to the meteorological range (\(L_{\rm{V}}\)): \(L_{\rm{V}}=\frac{3.9}{b_{\rm{scat}}}\); \(b_{\rm{scat}}\) and \(b_{\rm{abs}}\) represent the scattering and absorption coefficients per unit length for a light beam (of path length \(L\)) which has a spectral radiance (intensity) \(I_{0}\) incident on a sample of air and \(I\) is the transmitted spectral radiance (intensity), \(\ln (\frac{I_{0}}{I}) = L\ (b_{\rm{scat}}+b_{\rm{abs}})\). coefficient https://goldbook.iupac.org/terms/view/C01124 extinction https://goldbook.iupac.org/terms/view/E02293 scattering https://goldbook.iupac.org/terms/view/S05487 spectral radiance https://goldbook.iupac.org/terms/view/S05824 PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2212 (https://doi.org/10.1351/pac199062112167) https://goldbook.iupac.org/terms/view/S05490/html https://goldbook.iupac.org/terms/view/S05490/json https://goldbook.iupac.org/terms/view/S05490/plain Citation: 'scattering cross-section' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.S05490 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-06-30T15:25:00+00:00