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Trans-Eurasian Transport of Ozone and its Precursors. Oliver Wild, Pakpong Pochanart and Hajime Akimoto Frontier Research Center for Global Change Yokohama, Japan. Second ICAP Workshop, Oct 21, 2004, Chapel Hill, NC. Trans-Eurasian Transport. Motivation
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Trans-Eurasian Transport of Ozone and its Precursors Oliver Wild, Pakpong Pochanart and Hajime Akimoto Frontier Research Center for Global Change Yokohama, Japan Second ICAP Workshop, Oct 21, 2004, Chapel Hill, NC
Trans-Eurasian Transport Motivation • Trans-Pacific and Trans-Atlantic transport well studied • PEM-West, TRACE-P, ACE-Asia, NARE, ITCT • Trans-Eurasian transport less well understood due to location, landmass and meteorology • 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? Key Foci: Air Quality, Oxidizing Capacity, Climate
Continental Outflow in Spring N. American O3 European O3 4 ppbv isosurface of O3 in April
Ozone Over Japan Background O3 over Japan is rising • Rising NOx/CO/NMHC emissions over Asian mainland • What are the impacts from further afield? Ohara and Sakata 2003: Data from 341 monitoring stations
FRSGC/UCI Global CTM • Tropospheric gas-phase chemistry • Linearized stratospheric chemistry for O3 • Emissions for 1990 from EDGAR v2.0 • Driven by 2 sets of meteorology:
O3 and CO over Eurasia Mace Head Mondy Zugspitze Happo
Trajectories Arriving at 100°E viz. Newell and Evans [2000]
Trajectories Arriving at 100°E viz. Newell and Evans [2000]
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
Impacts at Mondy (52ºN, 101ºE) CO CO O3 O3
Impacts on CO over Japan in April 1996 • Patterns of European and N. American influence very similar • Transport pathways are similar • European influence about 25% greater
Impacts on CO over Japan in April 1996 10-8 kg/m2/s
Impacts on O3 over Japan in April 1996 • Patterns of European and N. American influence appear quite different • Transport pathways are similar, but timing of events is different • European influence on O3 is smaller than that from N. America
Impacts on O3 over Japan in April 1996 10-9 kg/m2/s
Surface O3 at Happo 60 ppbv Japan 1hr std European/N.American impacts persist during local pollution episodes (Apr 23-27): affect attainment of air quality standards
Annual Global Mean Profiles • Different impacts on OH and hence on CH4 • Expect different climate responses
Conclusions Impacts on Central Asia • High-latitude flow round Siberian High and Tibet • European impacts average 10-30 ppbv CO, 1-4 ppbv O3 • European influence on O3 suppressed in winter Impacts on Japan • Significant background enhancements in O3 and CO • Modest surface O3 impacts, but will affect Air Quality Stds • N. American influence larger than European in mid-trop Global Impacts • European emissions may lead to net decrease in OH • Significantly different indirect climate effects expected
Measurement Sites over Eurasia Mondy Vostochnaya Taishan Waliguan Happo Long-Term Measurements over Asia • Regionally polluted sites over China now operational • Transport from Europe occurs at high latitudes • More sites needed over Central and Northern Asia Huashan Huangshan