Evaluation of modelled versus observed NMVOC compounds at EMEP sites in Europe

• DOI: 10.5194/egusphere-2023-3102
• Publication Date: 2024-01-23T19:11:02Z
• Authors: Yao Ge; Sverre Solberg; Mathew Heal; Stefan Reimann; Willem van Caspel; Bryan Hellack; Thérèse Salameh; David Simpson
• Keywords: Emission inventory; Volatile organic compound; Butane; Atmospheric chemistry; Propane; TRACER; Box model

Abstract. Atmospheric volatile organic compounds (VOC) constitute a wide range of species, acting as precursors to ozone and aerosol formation. chemistry transport models (CTMs) are crucial understanding the emissions, distribution, impacts VOCs. Given uncertainties in VOC lack evaluation studies, recent changes this work adapts European Monitoring Evaluation Programme Meteorological Synthesizing Centre – West (EMEP MSC-W) CTM evaluate emission inventories Europe. Here we undertake first intensive model-measurement comparison VOCs two decades. The modelled surface concentrations evaluated both spatially temporally, using measurements from regular EMEP monitoring network 2018 2019, 2022 campaign. To achieve this, utilised UK National Emission Inventory derive explicit profiles for individual species employed `tracer' method produce pure that directly comparable observations. Model simulations compare use inventories, CAMS CEIP, chemical mechanisms, CRIv2R5Em EmChem19rc; those 2019 only. degree which measured agree varies depending on specific species. model successfully captures overall spatial temporal variations major alkanes (e.g., ethane, n-butane) unsaturated ethene, benzene), but less though propane, i-butane, ethyne. This discrepancy underscores potential issues boundary conditions these latter their primary emissions particular solvent road sectors. Specifically, missing propane with its highlighted by large underestimations smaller ethane ratios compared measurement. Meanwhile, measurement show strong linear correlations among butane isomers pentane isomers, indicating common sources pairs isomers. However, i- n-butane n-pentane approximately one-third ratios, is largely driven significant sector. suggests speciation profile sector, or underrepresented contributions fuel evaporation sectors current both. Furthermore, ethene-to-ethyne benzene-to-ethyne differ significantly ratios. different performance strongly points shortcomings patterns magnitudes ethyne especially during winter. For OVOCs, methanal methylglyoxal display good agreement, demonstrates photo-oxidation processes reasonably well. insufficiency suitable limits other OVOCs. Finally, exhibits very similar across likely exert more impact agreement between data than total reported each Therefore, future focus may need shift towards refining through example new campaigns improve accuracy.