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Observation and Modeling Evidence of Ozone Transport to and from Asia

LRTAP/EMEP Task Force on Hemispheric Transport of Air Pollutants, Brussels, June 1-3, 2005. 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)

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Observation and Modeling Evidence of Ozone Transport to and from Asia

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  1. LRTAP/EMEP Task Force on Hemispheric Transport of Air Pollutants, Brussels, June 1-3, 2005 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)

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

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

  5. O3 and CO over Eurasia Mace Head Mondy Zugspitze 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 O3: greatest in low/mid-trop in spring close to zero in winter PBL

  10. Remote Stations for Surface O3 from Europe to East AsiaMountain (1600-2000 m): Arosa, Mondy and HappoSea Level: Mace Head, Oki, and Okinawa

  11. Mondy, Russia Arosa, Switzerland 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 O3 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 O3 • 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 O3 and CO at Mondy during 1996-99 O3 CO Pochanart, Akimoto et. al Atmos. Environ., 2001

  18. Classification based on trajectories Monthly Mean Data Frequency Distributions (Annual Data) O3 O3 HL EU SI CO CO SI HL EU

  19. Comparison of Ozone in European Air mass with Others by Season Spring Summer Winter

  20. Impact of O3 and CO over Happo, Japan from Europe and N. America

  21. Impacts on O3 and CO over Happo, Japan from Europe and N. America in April 1996 O3 CO

  22. Contribution to Surface O3 at Happo by Difference Sources in April 1996 Japan EQS for Ox 60 ppbv 1hr av. European/N.American impacts persist during local pollution episodes (Apr 23-27): affect attainment of air quality standards

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

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

  25. Mondy 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 Waliguan EMEP Sites EANET/ GAW Sites & China

  26. Conclusions From CTM Studie • Significant European impacts over Central Asia • Average 10-30 ppbv CO, 1-4 ppbv O3 • Only slightly smaller impacts over Japan • Average 2-25 ppbv CO, 0.2-2.5 ppbv O3 • Present during anticyclonic conditions (affect AQ Stds) • N. American influence larger than European in mid-trop From Observations • Signature of European influence present in O3 and CO • Still difficult to quantify directly (new methods needed?)

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