1. ACCENT/GLOREAM 2006, 11-13 October, Paris Photo-oxidants formation and transport over Europe during the heat wave period in July 2006 Joanna Struzewska Warsaw University of Technology, Warsaw, Poland Jacek Kaminski York University, Toronto, Canada

2. ACCENT/GLOREAM 2006, 11-13 October, Paris Outline July 2006 case study GEM-AQ model description and experiment setup Result analysis – heat wave development Impact on photochemical pollution Summary Future plans

3. ACCENT/GLOREAM 2006, 11-13 October, Paris July 2006 – case study Prolonged heat wave period over Europe The hottest July since official measurements begun Two sub-periods might be distinguished Impacts Droughts Increased mortality Air quality problem over entire continent Extreme events over Western Europe

4. ACCENT/GLOREAM 2006, 11-13 October, Paris Heat wave development Based on weather services reports: July 3 rd - Heat wave in Western Europe (France) July 4 th - Hot air reached Central Europe July 6 th - Severe thunderstorms over Western Europe July 7 th - Hot air from over Africa passing towards Lithuania and Latvia July 13 th High air temperature across Europe – African air from the south-west and air from Asia from the east

5. ACCENT/GLOREAM 2006, 11-13 October, Paris Aim of the study Analysis of photochemical pollution during first heat wave period over Central Europe in July 2006 (July 3 – 14) Analysis based on GEM-AQ model simulation over Europe Meteorological situation over Europe used for the interpretation of air quality indices GEM-AQ model evaluation: Meteorological and air quality measurements - 14 stations from Poland Ozone measurements - 5 UK and 4 French stations (Airparif) Station type: rural / background

6. ACCENT/GLOREAM 2006, 11-13 October, Paris GEM-AQ model description The Canadian operational weather forecast model, the Global Environmental Multiscale (GEM) (Côté, et al., 1998) is used as a host meteorological model for inclusion of tropospheric air quality processes: Gas phase chemistry Aerosol chemistry and physics (not used in this study) Heterogenous chemistry (not used in this study) Antropogenic and biogenic emissions Dry and wet removal Vertical diffusion of gas and aerosol trace species

7. ACCENT/GLOREAM 2006, 11-13 October, Paris GEM-AQ experiment setup Grid: global variable resolution mode 0.135 deg (~15 km) over Europe (core) 400 x 350 (core) Time span: 3 - 14 of July 2006 Time step: 450 s. Modelling strategy OA every 6 hours used to produce trial fields Chemical initial conditions from 5-year run with GEM-AQ, 1.5x1.5 deg. uniform resolution

8. ACCENT/GLOREAM 2006, 11-13 October, Paris Model domain - core

9. ACCENT/GLOREAM 2006, 11-13 October, Paris Results’ analysis - meteorology Meteorological analysis: Synoptic situation (pressure patterns, circulation) Average temperature 10 – 17 LT (each day and averaged for the simulation period) Number of hours with the temperature exceeding 30 o C Cloudiness (averaged for the period)

10. ACCENT/GLOREAM 2006, 11-13 October, Paris Synoptic situation July 4 th Low pressure system forced transport of hot air masses towards Western Europe

11. ACCENT/GLOREAM 2006, 11-13 October, Paris Synoptic situation July 6 th Mutual location of pressure systems over Africa and Central Europe allowed for transport of hot air masses to the north

12. ACCENT/GLOREAM 2006, 11-13 October, Paris Synoptic situation July 13 th Circulation patterns causing the transport of hot air masses towards Europe from the south and east

13. ACCENT/GLOREAM 2006, 11-13 October, Paris Air temperature (8 hour average)

14. ACCENT/GLOREAM 2006, 11-13 October, Paris Number of hours with air temperature exceeding 30 o C

15. ACCENT/GLOREAM 2006, 11-13 October, Paris Average cloud cover

16. ACCENT/GLOREAM 2006, 11-13 October, Paris Result analysis - ozone Air quality indices - ozone: Maximum 8-h moving average – each day (area exposed to > 120 ug/m 3 ) Number of hours exceeding information treshold (180 μg/m 3 ) Number of hours exceeding alert treshold (240 μg/m 3 ) Average 8-hour concentration for the period (10 – 17 LT)

17. ACCENT/GLOREAM 2006, 11-13 October, Paris O 3 - maximum 8-h moving average

18. ACCENT/GLOREAM 2006, 11-13 October, Paris Information threshold exceedings

19. ACCENT/GLOREAM 2006, 11-13 October, Paris 8-hour average temperature and O 3

20. ACCENT/GLOREAM 2006, 11-13 October, Paris Comparison with O3 measurements Wicken Fen - UK

21. ACCENT/GLOREAM 2006, 11-13 October, Paris Comparison with O3 measurements Ramboulliet - France

22. ACCENT/GLOREAM 2006, 11-13 October, Paris Comparison with O3 measurements Widuchowa - Poland

23. ACCENT/GLOREAM 2006, 11-13 October, Paris Comparison with O3 measurements Mscigniew - Poland

24. ACCENT/GLOREAM 2006, 11-13 October, Paris Summary 1/4 The on-line GEM-AQ model reproduced correctly development of pressure systems and inflow of hot air masses towards Europe Good agreement with surface synoptic maps and meteorological measurements Heat wave during the first week of July 2006 was connected with the development of low pressure system over France and favourable anticyclonic circulation over Central Europe

25. ACCENT/GLOREAM 2006, 11-13 October, Paris Summary 2/4 Inflow of humid and relatively cooler air from over Atlantic Ocean towards Western Europe generated instability, causing severe thunderstorms and gales over France and Germany Stable high over Central-Eastern Europe blocked the front movement and transported hot air masses towards north-eastern Europe During the second week of July frontal systems over Westren Europe dissipated and hot air was transported from over Africa and Asia

26. ACCENT/GLOREAM 2006, 11-13 October, Paris Summary 3/4 The GEM-AQ model reproduced high ozone concentrations during heat wave period Good agreement with O 3 measurements (rural- background station type) Ozone variability better reproduced for UK and French monitoring stations Emission data might be less accurate for Central-Eastern Europe Bigenic emission used for this study might not be representative for heat wave period For some Polish stations ozone concentrations slightly overestimated especially during nighttime

27. ACCENT/GLOREAM 2006, 11-13 October, Paris Summary 4/4 High concentration of ozone affected most of European continent Air quality standards were exceeded especially in Central Europe (120 μg/m 3 8-h moving average and the information threshold exceeded) High pressure system allowed for persisting of hot and polluted air mass, clear sky and weak wind conditions enhanced photochemical production Ozone pollution in northern part and Baltic countries might be connected with transport but might has been enhances by biogenic VOC emisions during heat wave period

28. ACCENT/GLOREAM 2006, 11-13 October, Paris Future plans Numerical simulation for the period 15 – 31 of July Air mass ageing index analysis Analysis of biogenic VOC emissions (especially in Baltic countries) Comparison with other available AQ measurements and available satellite images