Term: deposition velocity https://doi.org/10.1351/goldbook.D01602 Definition: The ratio of flux density (often given in units of g cm-2 s-1) of a substance at a sink surface to its concentration in the atmosphere (corresponding units of g cm-3). While the units of this ratio are clearly those of velocity (in this case cm s-1), the ratio is not a flow velocity in the normal sense of the word. Source: PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2184 (https://doi.org/10.1351/pac199062112167) Citation: 'deposition velocity' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.D01602 License: 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. Disclaimer: 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.