AUTHOR=Stremme Wolfgang , Grutter Michel , Baylón Jorge , Taquet Noemie , Bezanilla Alejandro , Plaza-Medina Eddy , Schiavo Benedetto , Rivera Claudia , Blumenstock Thomas , Hase Frank TITLE=Direct solar FTIR measurements of CO2 and HCl in the plume of Popocatépetl Volcano, Mexico JOURNAL=Frontiers in Earth Science VOLUME=Volume 11 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2023.1022976 DOI=10.3389/feart.2023.1022976 ISSN=2296-6463 ABSTRACT=Volcanic CO 2 emissions inventories have a great importance to understand the geological carbon cycle. Volcanoes provide the primary pathway for Solid Earth volatiles to reach the Earth's atmosphere and have the potential to significantly contribute to the carbon-climate feedback.2012-2016 could be determined from a statistical treatment of the detected CO 2 and HCl columns in the IR spectra, and their corresponding molecular ratios. A total of 25 events were used to derive a mean CO 2 /HCl molecule ratio of 11.4± 4.4 and an average HCl emission rate of (3.0±0.3) kg/s could be determined. The CO 2 emissions of Popocat épetl were found to be around 0.32% of the total anthropogenic CO 2 emissions in the country (Instituto Nacional de Ecología y Cambio Clim ático (INECC), 2018) and 3.6% of the Mexico City Metropolitan Area (MCMA) , according to the corresponding emission inventories (Espinoza et al., 2018). CO 2 emissions from the Popocat épetl volcano can be considered to play a negligible role for the global CO 2 budget, but should be taken into account for the study of the carbon cycle on regional scales.