1. Observation and Modeling Evidence of Ozone Transport to and from Asia Hajime Akimoto (Oliver Wild and Pakpong Pochanart) Frontier Research Center for Global Change (FRCGC) Japan Agency for Marine-Earth Science and Technology (JAMSTEC) LRTAP/EMEP Task Force on Hemispheric Transport of Air Pollutants, Brussels, June 1-3, 2005

2. Free Troposphere Boundary Layer N. AmericaAsiaEurope Intercontinental Transport at Northern Mid-latitudes H H H L L L

3. Trans-Eurasian Transport Motivations Trans-Pacific and Trans-Atlantic transport well studied –PEM-West, TRACE-P, ACE-Asia, NARE, ITCT Trans-Eurasian transport less well understood Unique features –meteorological mechanisms for export –chemical influences due to latitude and meteorology –emissions and deposition over continent Questions How does pollutant export differ from that from N. America or East Asia? What are the impacts on oxidation and climate? To what extent does European pollution affect central and eastern Asia? How does this compare with N. American influence?

4. 10% Increase of Emission in N. America 10% Increase of Emission in Europe 10% Increase of Emission in E. Asia Model-calculated Characteristic of Intercontinental Transport from Three Continents Adapted from: O. Wild, H. Akimoto, J. Geophys. Res., 106, 27,729 (2001) longitude Height longitude

5. O 3 and CO over Eurasia Mace Head Zugspitze Mondy Happo

6. Export of Oxidants from Europe Horizontal transport in PBL dominates export Seasonal variation in export dependent on species

7. Can European Pollution Affect East Asia? Source: Newell and Evans [2000]

8. Trajectories Arriving at 100°E Newell and Evans [2000]

9. European Impacts at 100°E CO: greatest in high-latitude PBL in wintertime O 3 : greatest in low/mid-trop in spring close to zero in winter PBL

10. Remote Stations for Surface O 3 from Europe to East Asia Mountain (1600-2000 m): Arosa, Mondy and Happo Sea Level: Mace Head, Oki, and Okinawa

11. Arosa, Switzerland Mondy, Russia Happo, Japan

12. Seasonal Variation of Background Ozone in East Asia and Europe -Observation-

13. Seasonal Variation of Regionally Polluted Ozone in East Asia and Europe -Observation-

14. Differences in Surface Ozone between Europe and East Asia Derive regional background –remove local emissions Compare: Mace Head (Ireland) Arosa (Switzerland) Mondy (Siberia) Happo (Japan) East Asian Ozone lower in summer due to Asian monsoon Ozone 5-10 ppbv higher at Asian sites from autumn to spring – Why ?

15. Differences in Surface Ozone between Europe and East Asia Consider mean difference –Asian sites – European sites –local emissions removed Stratospheric influence greater over Asia –driven by subsidence over Central Asia Residual largely due to: –emissions over Europe –emissions over Eurasia Background O 3 higher over Asia –implications for air quality

16. Impacts of European Sources at 100º East CO –Winter/spring maximum, summer minimum –Boundary layer impacts greatest O 3 –Spring maximum, summer minimum –Additional minimum in winter –Greater impacts in mid- troposphere Mondy, 52N Can we detect European influence from the measurements?

17. Raw obserbational data of O 3 and CO at Mondy during 1996-99 Pochanart, Akimoto et. al Atmos. Environ., 2001 O3O3 COCO

19. Classification based on trajectories EU SI HL O3O3 O3O3 CO Monthly Mean DataFrequency Distributions (Annual Data)

20. Comparison of Ozone in European Air mass with Others by Season Spring SummerWinter

21. Impact of O 3 and CO over Happo, Japan from Europe and N. America

22. Impacts on O 3 and CO over Happo, Japan from Europe and N. America in April 1996 O3O3 CO

23. Contribution to Surface O 3 at Happo by Difference Sources in April 1996 60 ppbv 1hr av. European/N.American impacts persist during local pollution episodes (Apr 23-27): affect attainment of air quality standards Japan EQS for O x

24. Seasonal Variation of Trajectory Categorized ozone in Japan Rishiri Oki Okinawa Ogasawara

25. Trend of Annual Average Concentration of Ox and Precursors in Tokyo (Average of 23 Stations) Oxidant Measure Committee Report, Tokyo Metropolitan Government (2005)

26. Mondy Waliguan Vostochnaya (?) Long-term measurements needed over Eurasia Regional coverage over Asia relatively poor Transport from Europe occurs at high latitudes More sites needed over Central and Northern Asia EMEP SitesEANET/ GAW Sites & China

27. Conclusions From CTM Studie Significant European impacts over Central Asia – Average 10-30 ppbv CO, 1-4 ppbv O 3 Only slightly smaller impacts over Japan – Average 2-25 ppbv CO, 0.2-2.5 ppbv O 3 – Present during anticyclonic conditions (affect AQ Stds) – N. American influence larger than European in mid-trop From Observations Signature of European influence present in O 3 and CO – Still difficult to quantify directly (new methods needed?)