1. CHIMERE air quality forecasts : results during Pays de la Loire summer 2004 experiment and end-user point of view ! Arnaud REBOURS - AIR PAYS DE LA LOIRE ! ACRI-ST 1st CHIMERE workshop 21, 22 March 2005 -Palaiseau France

2. French air pollution control networks organization Air Pays de la Loire NANTES PARIS Pays de la Loire region : 3 200 000 inhab.; 32 000 km2 ! 2 missions : air quality survey and information

3. Air Pays de la Loire ! Territorial cover La Roche/Y Cholet Laval St-Nazaire ! 10 survey zones ! 50 survey sites ! continuous control ! 15 minutes time resolution Nantes Le Mans Angers

4. ! Modelisation tools ! Regional scale : Calgrid 10 august 2003 ! Street scale : OSPM NO2 - Nantes 2001 ! Industrial scale : Calpuff 11 feb. 2003 - refinery Scenario mode

5. CONTEXT ! 18 june 2004 french regulation : during pollution episodes, air quality public information is based on observations or on risk of exceedings of thresholds -> necessity of forecasting development ! Period : 13 july - 12 october 2004 ! Summer 2004 experiment : operation by ACRI-ST of an air quality forecast system based on MM5- CHIMERE over the Pays de la Loire region

6. LOCAL FORECASTING PLATFORM ! 2 zones : Great West area (15 km) and Pays de la Loire region (5 km) GWEST 15 km APL 5 km ! 2 pollutants : O3 and NO2 ! 4 daily outputs : D-1, D, D+1 and D+2 ! hourly time step

7. InputsOutputs Emissions inventory : 5km and 50 km Meteorological data : NCEP Continental chemistry : PREV AIR 2D Data Platform publication Maps Forecast computer : MM5-CHIMERE Interface computer Job programmer LOCAL FORECASTING PLATFORM

8. Meteo- rology pollution zone pollutant 4 days forecasts WEB INTERFACE

9. FORECAST PRELIMINARY RESULTS ! Observation data : 20 survey sites ! Statistical criteria : BIAS and NMSE

10. FORECAST PRELIMINARY RESULTS ozone

11. FORECAST PRELIMINARY RESULTS ozone

12. FORECAST PRELIMINARY RESULTS ozone

13. FORECAST PRELIMINARY RESULTS ozone

14. FORECAST PRELIMINARY RESULTS NO2

15. FORECAST PRELIMINARY RESULTS NO2

16. POST-PROCESSING ON FORECASTS ! Vigilance maps improve public information ! 13 alert zones :5 departments (counties), 7 agglomerations, 1 industrial area ! 3 symbolic colours : green, orange, red calculation ! 2 ways : forecasting observation validation

17. POST-PROCESSING ON FORECASTS ! Vigilance maps improve public information Forecasted exceeding Procedure activating conditions - agglomerations : 2 sites - departments : 2 agglomerations or 30% of the zone

18. communiqués (fax and e-mail) web site : www.airpl.org POST-PROCESSING ON FORECASTS ! Vigilance maps improve public information

19. POST-PROCESSING ON FORECASTS ! Air quality index prediction,...)= Annual maps ! Exceedings evaluations of limit values, quality objectives and target values

20. CONCLUSION ! Forecast results are acceptable for ozone and better than continental modeled values for NO2 ! Local platform brings helps to diagnosis : background pollution in the great west of France, influence of Paris pollution, meteorological forecast parameters ! Post processing improve air quality information in connection with alert system or daily pollution

21. PROSPECTS ! Integration of detailed emission calculations (AIREMIS) ! Integration of meteorological and pollution vertical profiles ! Local platform should be operated by Air Pays de la Loire during summer 2005 ! Statistical adaptation of modeled results with observations for D-1 and D steps

22. FORECAST PRELIMINARY RESULTS ozone

23. FORECAST PRELIMINARY RESULTS NO2 ! Emissions inventory comparison