Source apportionment methodologies Sample Clauses

Source apportionment methodologies. Classical methods to do source apportionment, such as receptor and source-oriented modelling approaches are available and becoming more widely used by member states. Nevertheless, it must be clear that even the most advanced tools have strengths and limitations. For instance receptor models are appropriate for urban areas and source- oriented sites, and can be used to identify main source categories even when there is poor information about source chemistry and location. However, these receptor models require time series of pollution measurements and chemical characterization and are not adequate for reactive species. In that case source-oriented approaches, such as eulerian models, that provide estimates of reactive species concentrations for every cell in the grid with hourly time resolution are suitable to estimate the sources of secondary pollutants. The complexity of these types of models makes it difficult to estimate the uncertainty of the output, which depends on the quality and resolution of the emission inventories. Therefore, the most robust approach to deal with source identification is the use of different models with the same data or with different data for the same area to simultaneously validate the results and assess the quality of the output quantitatively.