Fabio Monforti

THOSCANE: a tool to detail CORINAIR emission inventories

Abstract THOSCANE (Tool for HOurly Specification of CORINAIR ANnual Emissions) a software tool aimed at elaborating the emission inventories produced on the basis of the CORINAIR methodology for the needs of air quality modelling community, is presented here. Air quality modellers usually need very detailed information about emissions in the area studied. Also when a box model is applied, not considering spatial features of the emissions, other details have to be inferred from the inventory in order to correctly feed the model: the hourly time profile is usually required for all pollutants, whereas details on particulate matter size spectrum and chemical composition are necessary when dealing with PM modelling and suitable speciation profiles of emitted volatile organic compounds (VOCs) is a stringent requirement for modelling complex photochemical processes in the atmosphere. THOSCANE handles the emission inventory and all these profiles to obtain detailed emission patterns suitable for complex atmospheric box models.

Ozone Modeling over Italy: A Sensitivity Analysis to Precursors Using BOLCHEM Air Quality Model

The sensitivity of ozone to the reduction of NOx and VOC over Italy has been investigated with the air quality model BOLCHEM, which includes two photochemical mechanisms: SAPRC-90 and CB-IV. The study has been carried out for some case studies during the years 1999 and 2003. The results show the relative importance of precursors in reducing the ozone levels and allow identifying regions of Italy where local emissions reduction strategies are less effective. This study also shows the effect of the errors in isoprene inventories on ozone concentrations.

BOLCHEM Air Quality Model: Performance Evaluation over Italy

The modeling system BOLCHEM for air quality simulations has been run to study the evolution of tropospheric ozone over the Italian peninsula during 1999. The comparison of measured and modeled ozone time series shows that BOLCHEM predicts well the ozone concentrations. The summer cases are better simulated than the winter ones. The model configuration using SAPRC90 meets always the US-EPA criteria for the statistical indexes UPA, MNBE and MANGE. The Italian peninsula has a very complex topography, therefore the separation of meteorology and chemistry in offline simulations can lead to a loss of potentially important information about atmospheric processes, which often have a much smaller time scale than the meteorological output frequency. Here, we show the ability of a new developed air quality model, BOLCHEM, to reproduce the observed ozone concentrations for four clear sky periods (one from winter, the others from summer season) selected based on Meteosat images of Europe. The calculated O3 concentrations were compared with measurements made at rural or semi-rural stations. The statistical measures recommended by the U.S. Environmental Protection Agency (US-EPA, 2005) for air quality model validations were also computed for hourly values of ozone concentration. BOLCHEM couples the meteorological model BOLAM (Buzzi et al., 2003) to SAPRC90 (Carter, 1990), and CB-IV (Gery et al., 1989) as alternative photochemi- cal mechanisms. The mechanisms were chosen since they adopt different criteria for grouping the organic gases: CB-IV groups the organics according to bond type, while SAPRC90 groups them according to molecule type. Figure 1 shows that the agreement between simulated and measured ozone concentrations is good for both summer and winter. Generally, the model has diffi- culties in reproducing low ozone concentrations observed during the winter and during the night. A more extensive discussion of the results can be found in Mircea et al. (2007). Table 1 shows the statistical indexes recommended by US-EPA (US- EPA, 2005). It can be seen that generally, UPA is lower than 35%, MNBE is lower than 15%, MANGE is lower than 30-35%.