High resolution modelling of atmosphere-canopy exchange of acidifying and eutrophying components and carbon dioxide for European forests

The Integrated Deposition Model (IDEM) was improved by incorporating a novel multilayer biochemical dry deposition module for gases. The aerosol and base cation deposition module was adopted from IDEM. For evaluation of primary and ecosystem productivity, carbon respiration schemes were included. The resulting Framework for Atmosphere- Canopy Exchange Modelling (FACEM) was then evaluated by the case studies presented here. First, results for deposition of SOx, NOy and NHx were compared with site observations, showing correlations of up to R-2 = 0.60. Applicability for grid deposition calculations for these compounds was then evaluated for Europe. The model was clearly able to reproduce the elevated deposition near the important emission areas in Europe. Next, we compared the modelled CO2 fluxes with measurements from 26 European sites. Correlations of up to R-2 = 0.81 indicate good performance. To evaluate grid performance, the 2003 European heat wave was studied in a final case study, resulting in convincing correspondence with the observed productivity anomalies.