1. An experience on modelling-based assessment of the air quality within the Air Quality Directive framework Ana Isabel Miranda, Isabel Ribeiro, Patrícia Fernandes, Alexandra Monteiro, Cristina Monteiro, Carlos Borrego

2. Concentration Fixed measurements shall be used Combination of fixed measurements and modelling techniques and or indicative measurements may be used Upper assessment threshold Lower assessment threshold Modelling techniques or objective- estimation shall be sufficient SO 2, NO 2, NOx, PM10, PM2,5, Pb, C 6 H 6, CO Those fixed measurements may be supplemented by modelling techniques and/or indicative measurements to provide adequate information on the spatial distribution of the ambient air quality. 2008 Air Quality Directive| air quality assessment Assessment strategy depends on upper and lower assessment thresholds

3. Exceedances of upper and lower assessment thresholds shall be determined on the basis of concentration during the previous 5 years where sufficient data are available. An assessment threshold shall be deemed to have been exceeded if it has beed exceed during at least 3 separate years out of those previous five years. Assessment for 2010 and 2011 Upper and lower thresholds exceedances for 2006-2010 (5 years period).

4. Modelling 1. Model application to Portugal (5 km x 5 km), 2010 and 2011 2. Bias correction based on the multiplicative ratio adjustment technique 3. Evaluation (using the DELTA tool when possible) The approach Monitoring 1. Monitoring stations selection and data treatment, for the period 2006-2010 2. Comparison with the upper and lower thresholds, for every pollutant 3. 2010 data treatment for the model evaluation AQ assessment based on a combination of Modelling and Measuring values NO 2, O 3, PM10, PM2.5, SO 2, CO, C 6 H 6.

5. MM5-EURAD Meteorological conditions Emissions

6. 125x125 km 2 25x25 km 2 5x5 km 2 Simulation domains

7. Emissions EMEP 2008 for the larger domains Portuguese inventory 2008 for the portuguese domain Transports Industrial processes

8. Monitoring stations

9. SUBST an additive correction of the mean bias RAT a multiplicative ratio correction We started to compare… Bias-correction techniques

10. after BIAS correction, model results have a decrease > 70% on the average systematic error the multiplicative ratio: better correction technique Bias-correction techniques RAT & SUBST synoptic conditions are characterized by a 3-4 day period. (Borrego et al., 2011, Atmospheric Environment) O3O3 PM10

11. PM10 daily average (2010) Ervedeira monitoring station

12. NO 2 maximum daily (2010) Ervedeira monitoring station obs RAT04 original

13. Validation SO 2 Hourly values – Calendário 2010 RDE = 15%; R = 0.63;bias = -1.01 µg.m -3 ; MSE = 4.31 µg.m -3 measured modelled

14. SO 2 4 th maximum of the daily averages (protection of human health) Threshold values were not exceeded Upper Lower LV Zones and agglomerations

15. SO 2 2010 2011 It was not possible to have the needed data everywhere 4 th maximum of the daily averages (protection of human health) < LAT LAT-UAT > UAT

16. SO 2 Annual average winter period (ecosystem protection) 2010 2011 < LAT LAT-UAT >UAT

17. SO 2 Modelling results CORINE Land Cover 2006 GIS Annual average winter period (ecosystems protection)

18. SO 2 25 th maximum hourly value 2010 2011 LV

19. Validation NO 2 Hourly data

20. Validation NO 2 Hourly data

21. NO 2 Annual mean Zones and agglomerations Upper Lower LV

22. NO 2 Annual mean 2010 2011 LV < LAT LAT-UAT > UAT

23. NO 2 Annual mean Modelling results Population data at sub- municipality level GIS National roads network

24. NO 2 19 th maximum of the hourly averages (protection of human health) Zones and agglomerations Upper Lower LV

25. NO 2 2010 2011 19 th maximum of the hourly averages < LAT LAT-UAT > UAT LV

26. NO 2 19 th maximum of the hourly averages

27. NO 2 Number of hours exceeding the LV 2010 2011

28. Validation PM10 Daily average

29. Validation PM10 Daily average

30. PM10 Annual average 2011 2010 < LAT LAT-UAT > UAT LV

31. 2011 2010 PM10 Daily average < LAT LAT-UAT > UAT LV

32. Notwithstanding this modelling work no modelling-based report to the Comission was delivered. This work was requested by the Portuguese Agency for the Environment. It was presented to the national agency and to the different regional entities in charge of the air quality assessment in Portugal. Several comments and feedbacks were received. They were very interested and willing to do a cost-benefit analysis of using modelling tools and reducing monitoring stations instead of keeping the maintenance costs they’re facing nowadays. We’re doing 2012 and we’re going to increase spatial resolution. Final comments

33. But … There is a strong difficulty to trust models and people is afraid of using them, because: they were always working with AQ monitoring networks and that’s what they know they think models are a kind of “monster” and they do not provide a really added value February 2009

34. Attitude towards models changed and people are much more receptive to their use for air quality assessment. Thanks to FAIRMODE!!!!

35. www.ua.pt/gemac miranda@ua.pt Thank you very much!!!