The collection contains monthly/yearly inverse modelling results of European non-CO2 greenhouse gas fluxes for the period 2017-2024 (FLEXPART) and 2013-2024 (NAME). The files are prepared for use with the Inverse Modelling Intercomparison Tool 'fluxy' available from https://github.com/openghg/fluxy. Results were obtained with three different inverse modelling systems: RHIME (https://doi.org/10.5194/acp-14-3855-2014), InTEM (https://doi.org/10.5194/acp-21-12739-2021), and ELRIS (https://doi.org/10.5194/acp-16-3683-2016). All systems used transport simulations from the Lagrangian Particle Dispersion Models NAME (https://doi.org/10.1007/978-0-387-68854-1) and FLEXPART (https://doi.org/10.5194/acp-5-2461-2005). The dataset was generated in the framework of the Horizon EU project PARIS (Grant Agreement nr 101081430, https://horizoneurope-paris.eu/, https://doi.org/10.3030/101081430). GHG flux estimates and their uncertainties are provided for the larger North Atlantic domain containing parts of North America and all of Europe, whereas observational constraint, depending on the compound, is mainly limited to Western, Central and Northern Europe. Flux estimates outside this general area are a associated with large uncertainties and potential biases and, as such, are not suitable for comparison or validation purposes. Similarly, observational coverage generally improved during the period coved by the inverse modelling, leading to a general reduction of uncertainty over time, whereas earlier results may lack sufficient certainty for quantitative interpretation. National emission totals are provided only for European countries (and/or regions) with smallest general uncertainties for the region comprising Ireland, United Kingdom, France, Belgium, Luxembourg, Netherlands and Germany. An interpretation of the results for eight focus countries is available as deliverable D2.3 from the project homepage (https://horizoneurope-paris.eu/deliverables/).

The inverse modelling is based on surface based in-situ and flask sampling observations primarily obtained from two sources. 1) The ICOS carbon portal for the European ObsPack methane (https://doi.org/10.18160/X5ZG-C3WE) and nitrous oxide collections (https://doi.org/10.18160/T18D-C85R). 2. Additional observations of synthetic gases obtained as part of the project PARIS, the AGAGE and DECC networks, available from the ICOS carbon portal (https://doi.org/10.18160/JK51-GFYB). The latest observations of synthetic gases from AGAGE stations is available from (https://doi.org/10.60718/75d7-qe84). Whenever the current dataset is used in further analysis and publications, the authors/creators should be contacted to assure proper use and interpretation.