High-resolution emission inventory of the Lombardy region: development and comparison with measurements

In the framework of the EUROTRAC-2 subproject limitation of oxidant production an emission inventory was developed for the Lombardy region in Italy with a 1 h temporal and 3 km spatial resolution. The emissions were processed in a bottom-up approach. We outline the emissions processing strategy used and summarize the inventory characteristics. Spatial maps and diurnal series charts of the total emissions of nitrogen oxides (NO x ), carbon monoxide CO, volatile organic compounds (VOC) are provided. The emission inventory shows distinct patterns for the urban area and the non-metropolitan region. We compare ratios of CO to NO x and CO to different VOC-classes between the emission inventory and measurements performed at two sites representative for the urban and non-metropolitan areas. Ratios were determined from the slopes of correlations between CO and the respective species class. Observed CO/NO x ratios are higher in the urban and non-metropolitan area by factors of 2 and 3, respectively. CO/VOC ratios show different discrepancies depending on the VOC-class but are generally lower in the emission inventory. Observations at the two sites yielded similar concentration ratios opposite to the inventory.