Applying the delta tool to support the Air Quality Directive: evaluation of the TCAM chemical transport model

Abstract

This paper presents an application of the DELTA evaluation Tool V3.2 to support the EU Air Quality Directive (AQD, 2008). This software, designed in the frame of the FAIRMODE project (Forum for Air Quality Modelling in Europe, http://fairmode.ew.eea.europa.eu/), is currently used as support to working groups of modellers across Europe in the diagnostics and assessment of air quality model performances under the AQD (2008). The skills of the DELTA Tool V3.2 are tested by looking at the results of a one-year (2005) simulation performed by the Transport Chemical Aerosol Model (TCAM) model (Carnevale et al. 2008) at 6x6 km2 resolution over the Po Valley. Modelled daily PM10 concentrations at surface level are compared to observations provided by approximately 50 stations distributed across the domain. The main statistical parameters (i.e. Bias, Root Mean Square Error, correlation coefficient, standard deviation) as well as different types of diagrams (scatter plots, time series plots, Taylor and Target plots) have been produced. The representation of the observation uncertainty in the Target plot, used to derive model performance criteria (MPC) for the main statistical indicators is also presented and discussed.