CITES 2007 (APN Workshop on Atmospheric Composition and Air Quality), Tomsk, July 20-21, 2007 Tropospheric Ozone and Its Impact on Climate and Environment Hajime Akimoto Frontier Research Center for Global Change Japan Agency for Marine-Earth Science and Technology Acknowledge to APN
Contents 1. Importance of Tropospheric Ozone 2. Global Perspective of Tropospheric Ozone 3. Hemispherical Perspective of Tropospheric Ozone 4. Transport of ozone from Siberia to China to Japan 5. Impact on Vegetation and Climate
1. Importance of Tropospheric Ozone • Toxic Gas Human Health Plant Health (Forest trees and agricultural crops) • Greenhouse Gas Third GHG next to CH 4 in global average Second GHG next to CO 2 in NH average • GHG-Lifetime Controlling Gas CH 4 , HCFC, etc.
Tree Decline in USA Mt. Mitchell (North Carolina ） Appalachian Mountains San Bernardino (California)
Contribution to Global Warming of Each Atmospheric Trace Species - Radiative Forcing during 1850-2000 - Black White Soil Cloud Particle Particle Trop. CO 2 CH 4 CFC N 2 O O3 Long-lived GHG Short -lived Air Pollutants (Kyoto Gases ） Sato and Hansen (2003)
OH January Global OH concentrations O 3 + h ν → O ( 1 D) + O 2 O( 1 D) + H 2 O → 2OH OH + CH 4 , HCFC, etc. → products OH July Global CH 4 lifetime = 9.4 yr Global CH 3 CCl 3 lifetime = 5.0 yr
2. Global Perspective of Tropospheric Ozone • Global Historical Trends • Global Distribution
Trend of Near Surface Ozone in 1870-2000
Historical Trend of Global NOx Emission (TgN/yr) van Aadenne et al., Global Biogeochem. Cycles, 15, 909, 2001
Comparison of Global Surface Ozone Distribution between Pre-industrial Era ant the Present 1860 May-August 1993 May-August Lelieveld, J., F. Dentener, J. Geophys. Res., 105, 3531-3551 (2000).
Surface ozone distributions (ppbv) Jan./Apr./Jul./Oct. January April July October K. Sudo, J. Geophys., Res. 2002
3. Hemispherical Perspective of Tropospheric Ozone • East Eurasian Continental “Background” - Our Mondy Station - • Intercontinental Transport and Hemispherical Air Pollution - Trans-Eurasian Transport -
WMO/GAW Observation Sites for CO Uniqueness of Our Station, Mondy
Our Observation Network for Regional and Hemispherical Air Pollution Mondy, Russia （ 2006 m) (51 ° 39N 100 ° 55E) Vostochnaya ● NOx emission map in 1990 100 ° E
Establishment of remote “ background ” site in Eastern Siberia Mondy Ozone and CO seasonal cycle
Long-term ozone observation from 1996 to present
Long-term CO observation from 1996 to present Data missing period Due to instrument Problem and project discontinuit
Seasonal cycle of background ozone and CO at Mondy CO O 3 350 80 Mondy CO 9703-9912 Mondy ozone 9610-9912 300 70 Max: 55 ppb Max: 200 ppb 60 250 Ozone mixing ratio (ppb) CO mixing ratio (ppb) 50 200 40 150 30 100 20 Min: 35 ppb 50 Min: 75 ppb 10 0 0 Sep-96 Jan-97 May-97 Sep-97 Jan-98 May-98 Sep-98 Jan-99 May-99 Sep-99 -- Sep-96 Jan-97 May-97 Sep-97 Jan-98 May-98 Sep-98 Jan-99 May-99 Sep-99 -- Month Month Both show spring maximum and summer minimum – typical ozone and CO pattern in remote Northern Hemisphere
Daily Variation of Ozone And CO at Mondy -”Remote” CO January, 1998 O 3 April, 1998 July, 1997 October, 1997
Comparison of O3 observation at nearby Khulugaisha (3000 m) with Mondy (2006 m) Very good correlation between Mondy and Khulugaisha 100 90 is confirmed. Mondy = 0.87Khulugaisha + 4.77 80 R= 0.86 70 Mondy ozone (ppb) 60 50 Mondy has been proved to be as an 40 30 excellent remote “background” station. 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Khulugaisha ozone (ppb) Data from March 2004 to March 2005
Ozone data at Mondy in comparison with data at Listvynka, on Baikal Lake shore during winter 2003 to spring 2004 Ozone drop at Listvynka indicated local NO pollution from Listvynka or Irkutsk
Intercontinental Transport and Hemispherical Air Pollution • Relevant to the issue of global air quality, intercontinental transport and hemispherical air pollution is now attracting international concern. • Task Force on Hemispherical Transport of Air Pollution (TF HTAP) has been organized under CLRTAP. • Ozone, aerosols, POPs, and Hg are the most concerned species.
Intercontinental Transport at Northern Mid-latitudes Free Troposphere Boundary Layer N. America Europe Asia L L L H H H
Can European Pollution Affect East Asia? Source: Newell and Evans [2000]
Remote Stations for Surface O 3 in Europe and East Asia Mountain (1600-2000 m): Arosa, Mondy and Happo Sea Level: Mace Head
Mondy, Russia Arosa, Switzerland Happo, Japan
Differences in “Background” Surface Ozone between Europe and East Asia (Trajectory categorized Observational Data) Continental Background East Asia is 5-10 ppb higher than Europe Atlantic Background
Differences in “Background” Ozone between Europe and East Asia can be reproduced by a model. 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 ? O. Wild (unpublished)
Differences in Surface Ozone between Europe and East Asia 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 O. Wild (unpublished)
Can we detect European influence of surface ozone at Mondy?
Observational Evidence of European Influence of O 3 and CO at Mondy Frequency Distributions (Annual) Annual Average Concentration 500 a) Ozone O 3 Europe Siberia 400 High Latitude Amount of Data (hr) 300 200 O 3 and CO in 100 European airmass is higher than 0 20 30 40 50 60 70 80 HL EU SI Siberian and Arctic Ozone mixing ratio (ppb) 250 airmass. b) CO CO Europe Siberia 200 High Latitude Amount of data (hr) 150 100 50 0 50 100 150 200 SI HL EU CO mixing ratio (ppb)
4. Transport of ozone from Siberia to China to Japan • East Asian Air mass • Regional Ozone Pollution in China • Regional Ozone Pollution In Japan
Emission Trends of NOx and SO 2 30000 China India 25000 NOx Japan East Asia SouthEast Asia South Asia 20000 15000 10000 5000 0 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 45000 China India 40000 Japan East Asia SO 2 SouthEast Asia South Asia 35000 30000 25000 20000 15000 10000 5000 0 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
Typical Air Masses in East Asia
Three Mountain Observation Sites in China （ North China Plain ） 1538 m 2063 m NO 2 Column by SCIAMACHY Mt. Tai Mt. Hua Mt. Huang 1836 m
Seasonal cycles of ozone at three Chinese mountain Chinese mountain sites and sites and Seasonal cycles of ozone at three Siberia (monthly average) at Mondy in East in East Siberia at Mondy
Ozone variation in March 2005 100 2005 80 60 Ozone (ppb) 40 20 Mondy Khulugaisha Taishan 0 1-Mar 5-Mar 9-Mar 13-Mar 17-Mar 21-Mar 25-Mar 29-Mar Date
Concentrations of O 3 , and CO at Mt. Tai in June 2006 (Hourly Average) June, 2006
Classification of Trajectories Reaching to Oki, Japan
Estimation of Contribution of Continental Pollution to Japan based on Observation Continental Polluted Air Mass Continental Contribution of Clean Air Mass Continental Pollution
5. Impact on Vegetation and Climate • Impact on Vegetation: - AOT 40 - • Impact on Climate - Difference from long-lived (well-mixed) GHG -
AOT 40 for remote sites in Japan
Remote O 3 Observation Sites in Japan
Seasonal Variation of Ozone at remote sites in Japan 80 80 Rishiri 1998-2000 Rishiri Okinawa Okinawa 1995-1996, 1998 70 70 60 60 Ozone concentration (ppb) Ozone concentration (ppb) 50 50 40 40 30 30 20 20 10 10 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Month 80 80 Oki 1994-1998 Ogasawara 1997-1998 Oki Ogasawara 70 70 60 60 Ozone concentration (ppb) Ozone concentration (ppb) 50 50 40 40 30 30 20 20 10 10 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Month
AOT 40 (Accumulated Exposure Over a Threshold of 40 ppb) AOT40 = Σ ([O3] i - 40) δ i δ i = 0 for [O3] ＜ 40 ppb δ i = 1 for [O3] ≧ 40 ppb
Critical Level of Ozone for Forest Trees and Agricultural Crops AOT40 Accumulated Period (ppb ・ h) Crops 5,300 May-July, daylight hours Forest 10,000 April-September, 24 h per day Daylight Hours: Hours with a mean radiation of 50 W or greater
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