Comparing three vegetation monoterpene emission models to measured gas concentrations with a model of meteorology, air chemistry and chemical transport

[摘要] Biogenic volatile organic compounds (BVOCs) are essential in atmosphericchemistry because of their chemical reactions that produce and destroytropospheric ozone, their effects on aerosol formation and growth, and theirpotential influence on global warming. As one of the important BVOC groups,monoterpenes have been a focus of scientific attention in atmosphericresearch. Detailed regional measurements and model estimates are needed tostudy emission potential and the monoterpene budget on a global scale. Sincethe use of empirical measurements for upscaling is limited by many physicaland biological factors, such as genetic variation, temperature and light,water availability, seasonal changes, and environmental stresses,comprehensive inventories over larger areas are difficult to obtain. Weapplied the boundary-layer–chemistry-transport model SOSA (model to Simulate the concentrations ofOrganic vapours and Sulphuric Acid) to investigateScots pine (Pinus sylvestris) monoterpene emissions in a boreal coniferous forest at theSMEAR (Station for Measuring forestEcosystem–Atmosphere Relations) II site, southern Finland. SOSA was applied to simulate monoterpeneemissions with three different emission modules: the semiempirical G95,MEGAN (Model of Emissions of Gases andAerosols from Nature) 2.04 with improved descriptions of temperature and light responses andincluding also carbonyl emissions, and a process-based model SIM–BIM (SeasonalIsoprenoid synthase Model – Biochemical Isoprenoid biosynthesis Model). Forthe first time, the emission models included seasonal and diurnal variationsin both quantity and chemical species of emitted monoterpenes, based onparameterizations obtained from field measurements. Results indicate thatmodelling and observations agreed reasonably well and that the model can beused for investigating regional air chemistry questions related tomonoterpenes. The predominant modelled monoterpene concentrations, α-pinene and Δ³-carene, are consistent with observations.

[学科分类] 地球化学与岩石