Modeling of elemental carbon over Europe

The regional EMEP model has been applied to calculate EC concentrations over Europe for the years 2002-2004 using a new EC emission inventory. The results are compared with measurements from the CARBOSOL and EMEP EC/OC campaigns. The model underestimates EC concentrations by 19% on average, and the spatial correlation is 0.80. For individual sites, the model bias varies from - 79 to 77% and the average temporal correlation is 0.53, varying from 0.25 to 0.79. The model flattens the north- south EC gradient as it tends to overestimate EC for Nordic sites and underestimate EC for more southern sites. We have also studied the contributions of various processes to the model EC results. Using EC as a tracer of primary PM emissions from combustion sources we have made a preliminary evaluation of the anthropogenic EC (PM) emission. There are indications of a possible underestimation of EC emissions from traffic in some areas and both underestimation and overestimation of EC emissions from residential combustion for some European countries. The largest uncertainties probably lie in EC emissions from residential wood/fossil combustion and are associated with both emission factors and spatial and temporal variation. The need to develop accurate and time resolved wildfire emissions is emphasized. The effect of EC aging is shown be rather limited for most of Europe (1 to 4%). Changes in EC wet scavenging ratio have a noticeable effect on calculated EC (between 5 and 25% for most Europe and 30-40% in remote areas), but EC scavenging ratios are still poorly known.