This work investigates the impact of the inorganic thermodynamic module on chemical transport model simulation. The study has been focused on Northern Italy, one of the most polluted area in Europe, where high PM10 levels are reached despite the Regional and National Authority efforts to limit emission in the atmosphere. Two different configurations of the Chemical Transport Model TCAM have been tested performing yearly simulation over the selected domain for 2005. In the first configuration, the SCAPE2 thermodynamic module has been implemented, while in the second one, ISORROPIA-II has been integrated into the system. An exhaustive evaluation of the performances is presented for total PM10 with respect to its daily values, measured in a subset of the monitoring sites available, and the differences in aerosol speciation have been analyzed in 4 stations with data collected in the frame of PARFIL monitoring campaign. The ISORROPIA-II module configuration shows better overall performances both in terms of correlation and Normalized Mean Absolute Error for PM10. The chemical evaluation of the inorganic ions performances shows quite different behavior for the two configurations, with ISORROPIA-II providing better results for Normalized Mean Absolute Error and Normalized Mean Error.
