A Comprehensive NMVOC Speciation Database for European Atmospheric Modelling.

Speciated non-methane volatile organic compound (NMVOC) emissions are essential for air quality modelling, as they underpin atmospheric oxidation processes, secondary pollutant formation, and the evaluation of mitigation strategies. Yet, these emissions remains poorly quantified in Europe. Here, we introduce a new database of NMVOC speciation profiles that prioritises European-specific data consistent with present-day technologies, fuels, and regulatory frameworks, and covers all anthropogenic emission sources reported by European countries. The database includes 130 chemical speciation profiles and over 900 individual NMVOC species, systematically compiled and harmonised from the literature. To facilitate integration within official emission inventories, the profiles are mapped to the Selected Nomenclature for Air Pollution (SNAP) and Nomenclature for Reporting (NFR) sector classifications. Each profile provides species-level mass fractions and their aggregation into the 25 Global Emissions Inventory Activity (GEIA) NMVOC groups, enabling straightforward integration with chemical mechanisms used in contemporary air quality models. In addition, a ready-to-use file compatible with the Copernicus Atmosphere Monitoring Service European regional emission inventory (CAMS-REG) is provided.