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**How to cite this article:** Wagner, A, Bennouna, Y, Blechschmidt, A-M, Brasseur, G, Chabrillat, S, Christophe, Y, Errera, Q, Eskes, H, Flemming, J, Hansen, KM, Inness, A, Kapsomenakis, J, Langerock, B, Richter, A, Sudarchikova, N, Thouret, V, Zerefos, C. 2021. Comprehensive evaluation of the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis against independent observations: Reactive gases. *Elementa: Science of the Anthropocene* 9(1). DOI: https://doi.org/10.1525/elementa.2020.00171.

**Domain Editor-in-Chief:** Detlev Helmig, Boulder AIR LLC, Boulder, CO, USA

**Knowledge Domain:** Atmospheric Science

**Published:** May 21, 2021

**Accepted:** April 6, 2021

**Submitted:** November 23, 2020

**Copyright:** © 2021 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/.
**How to cite this article:** Wagner, A, Bennouna, Y, Blechschmidt, A-M, Brasseur, G, Chabrillat, S, Christophe, Y, Errera, Q, Eskes, H, Flemming, J, Hansen, KM, Inness, A, Kapsomenakis, J, Langerock, B, Richter, A, Sudarchikova, N, Thouret, V, Zerefos, C. 2021. Comprehensive evaluation of the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis against independent observations: Reactive gases. *Elementa: Science of the Anthropocene* 9(1). DOI: https://doi.org/10.1525/elementa.2020.00171.

**Domain Editor-in-Chief:** Detlev Helmig, Boulder AIR LLC, Boulder, CO, USA

**Knowledge Domain:** Atmospheric Science

**Published:** May 21, 2021

**Accepted:** April 6, 2021

**Submitted:** November 23, 2020

**Copyright:** © 2021 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/.

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