Influence of boundary conditions and anthropogenic emission inventories on simulated O3 and PM2.5 concentrations over Lebanon

Özet

This study investigates the influence of boundary conditions and anthropogenic emission inventories onthe simulated O3 and PM2.5 concentrations over a middle-eastern country e Lebanon. The Polyphemuschemical transport model (CTM) is used over Lebanon to simulate O3 and PM2.5 concentrations. Comparisonsto measurements at a sub-urban site of Beirut between 2 and 13 July 2011 show that O3 islargely over-estimated when concentrations from a large-scale model are used as boundary conditions,as used in Waked et al. (2013). A global anthropogenic emission inventory (EDGAR-HTAP) is used withPolyphemus, in order to provide anthropogenic emissions for the Middle-East domain. Over Lebanon,sensitivity to emissions and to boundary conditions have been investigated. The comparison of EDGARHTAPto Waked et al. (2012) over Lebanon highlights high discrepancies between the inventories both interms of emission estimates and spatial distribution. However, when studying the sensitivity toboundary conditions, O3 is well modeled when a Middle-East domain and the Lebanon domain arenested and thus achieves better statistics. The observed concentration is 48.8 mg m3 and the respectiveconcentrations for the simulation using MOZART4 and the one using the Polyphemus/Middle-East are154.8 and 65.1 mg m3. As for PM2.5 which is less sensitive to regional transport than O3, the influence ofthe boundary conditions on the PM2.5 concentrations at the site of comparison is low. The observedconcentration is 20.7 mg m3, while the modeled concentrations are 20.7 and 20.1 mg m3 respectively