Comparison of modelled and monitored deposition fluxes of sulphur and nitrogen to ICP-forest sites in Europe
Résumé
Concerning precipitation, the EMEP model and ICP network showed very similar overall levels (within 4% for 1997 and 11% for 2000). The correlation was, however, poor (r2=0.15?0.23). This can be attributed largely to the influence of a few outliers, combined with a small range of rainfall amounts for most points. Correlations between modelled and observed deposition values in this study were rather high (r2 values between 0.4?0.8 for most components and years), with mean values across all sites being within 30%. The EMEP model tends to give somewhat lower values for SO2?4, NO3? and NH4+ wet deposition to ICP, but differences in mean values were within 20% in 1997 and 30% in 2000. Modelled and observed concentrations of SO2?4, NO3? and NH4+ in precipitation are very similar on average (differences of 0?14%), with good correlation between modelled and observed data (r2=0.50?0.78). Differences between the EMEP model and ICP measurements are thought to arise from a mixture of problems with both the observations and model. However, the overall conclusion is that the EMEP model performs rather well in reproducing patterns of S and N deposition to European forests.