The Ambient Air Quality Directives offer the opportunity for Member States (MS) to report on the air quality status via the use of modelling results. The Implementing Provision on Reporting (IPR) and related e-Reporting process have accelerated and strengthened this possibility. As a result, an increasing number of MS are reporting modelling data. However, there is still a clear lack of guidance on the use of model results in the formal reporting cycle (e.g. estimation of exceedances, exposure in given areas or spatial representativeness of the monitoring station). Based on the work carried out in the past years, the ambition is to prepare guidance to support best practices in this respect. The activities within this crosscutting task focus on:

• 1 Providing guidance on the assessment of spatial representativeness of monitoring stations depending of the context of the application domain. This can involve/require network optimization, selection of stations for model validation and assimilation or exceedances estimated
• 2 Defining specific methods to assess the estimation of areas and population exposed to exceedances
• 3 Providing guidance on fit-for-purpose modelling approaches to assess exposure and exceedances indicators
• 4 Supporting the e-reporting process in relation to the "Exceedance situation" data type