TY - JOUR

T1 - Trans-Eurasian transport of ozone and its precursors

AU - Wild, O

AU - Pochanart, P

AU - Akimoto, H

PY - 2004/6/2

Y1 - 2004/6/2

N2 - Long-range transport of air across the European and Asian continents brings substantial quantities of ozone and other oxidants to northeast Asia from upwind sources over Europe and North America. This transport differs significantly from that over the Pacific and Atlantic Oceans because of weaker and less frequent frontal systems over the continent and because of weaker convective lifting over European sources. Slower O-3 formation, faster destruction at low altitudes, and greater deposition over continental regions lead to Europe having a smaller impact on O-3 than other source regions. We present chemical transport model studies of the formation and transport of O3 from European precursor sources and investigate the extent of their impacts over Eurasia. We focus on measurement sites at 100degreesE, representing the inflow to east Asia on which regional pollutant sources build, and on northeast Asia, which may be directly affected by transport across Eurasia. The seasonality in O-3 production over Europe is simulated well, and transport principally in the boundary layer propagates these changes in O-3 over Eurasia, leading to monthly mean impacts at Mondy, Siberia, of 0.5-3.5 ppbv. Impacts over Japan are smaller, 0.2-2.5 ppbv, and are very similar to those from North American sources, which dominate at higher altitudes. By following the effect of daily emissions independently, we clearly demonstrate that this greater North American impact is associated with lifting over the Atlantic. European and North American sources contribute to background O-3 over Japan in the anticyclonic conditions that favor regional O-3 buildup and are thus expected to have a small but significant effect on regional air quality. Finally, we demonstrate that location and transport lead to European sources having a different impact on OH, and hence on tropospheric oxidizing capacity and climate, from other major Northern Hemisphere source regions.

AB - Long-range transport of air across the European and Asian continents brings substantial quantities of ozone and other oxidants to northeast Asia from upwind sources over Europe and North America. This transport differs significantly from that over the Pacific and Atlantic Oceans because of weaker and less frequent frontal systems over the continent and because of weaker convective lifting over European sources. Slower O-3 formation, faster destruction at low altitudes, and greater deposition over continental regions lead to Europe having a smaller impact on O-3 than other source regions. We present chemical transport model studies of the formation and transport of O3 from European precursor sources and investigate the extent of their impacts over Eurasia. We focus on measurement sites at 100degreesE, representing the inflow to east Asia on which regional pollutant sources build, and on northeast Asia, which may be directly affected by transport across Eurasia. The seasonality in O-3 production over Europe is simulated well, and transport principally in the boundary layer propagates these changes in O-3 over Eurasia, leading to monthly mean impacts at Mondy, Siberia, of 0.5-3.5 ppbv. Impacts over Japan are smaller, 0.2-2.5 ppbv, and are very similar to those from North American sources, which dominate at higher altitudes. By following the effect of daily emissions independently, we clearly demonstrate that this greater North American impact is associated with lifting over the Atlantic. European and North American sources contribute to background O-3 over Japan in the anticyclonic conditions that favor regional O-3 buildup and are thus expected to have a small but significant effect on regional air quality. Finally, we demonstrate that location and transport lead to European sources having a different impact on OH, and hence on tropospheric oxidizing capacity and climate, from other major Northern Hemisphere source regions.

KW - tropospheric ozone

KW - intercontinental transport

KW - CARBON-MONOXIDE

KW - TROPOSPHERIC OZONE

KW - AIR-POLLUTION

KW - INTERCONTINENTAL TRANSPORT

KW - NORTH-ATLANTIC

KW - SURFACE OZONE

KW - MACE-HEAD

KW - SEASONAL-VARIATION

KW - ASIAN EMISSIONS

KW - UNITED-STATES

U2 - 10.1029/2003JD004501

DO - 10.1029/2003JD004501

M3 - Journal article

VL - 109

SP - -

JO - Journal of Geophysical Research: Atmospheres

JF - Journal of Geophysical Research: Atmospheres

SN - 0747-7309

IS - D11

M1 - D11302

ER -