Spatial representativity : report of 2013 WG2/SG1 activity

The attached document addresses the progress of the FAIRMODE/SG1 activity since it starts in June 2013 up to the month of November 2013, for a total of about 100 working days. During this period the analysis has focused on the development of a novel methodology - point-centred semi variogram (pcsv) - for help assessing the spatial representativeness of the air quality receptors in Europe. The technique has been successfully developed and tested on a proxy of measured ambient air quality concentration data, namely results from an atmospheric modelling system. Action taken: 1. Established collaboration with the CERC group of the UK, developer and distributor of the Atmospheric Dispersion Modelling System (ADMS), for sharing of model results of pollutant dispersion in London. These data have been used as proxy in our analysis; 2. Established collaboration with the ARIA technologies SA of France for sharing of the AIRCITY high resolution modelling results of pollutant dispersion in Paris. The ARIA group has manifested the willingness to cooperate on the SG1 activity, although data for Paris have not yet been exploited. 3. Development, testing, and coding of the pcsv technique; 4. Application of the pcsv methods to the ADMS data using the positioning of European AIRBASE air quality receptors as centre of the analysis; 5. Preparation of the attached report. We note that about 90% of the total time has been spent on item 3 and 4 of the action list. The code we have produced is computing-intensive and has been run at the limit of the available computing resources (single PC unit). The code requires about ten days to complete a full run (three species, two years, fourteen central points). The results obtained are promising, the technique is robust and applicable to several pollutants, though it should be considered that generalisation is difficult, as any other cases needs to be treated individually. The necessity of developing a generalised method will require more time as other cases will need to be considered and the analogies among them taken in to account.