Modeled trend and future projection of surface ozone in East Asia

Transcription

1 1 November 16, 2011 Tripartite Workshop on Scientific Research of Photochemical Oxidant Modeled trend and future projection of surface ozone in East Asia Toshimasa Ohara National Institute for Environmental Studies (NIES), Japan Hiroshi Tanimoto, Tatsuya Nagashima, Masato Nishizawa (NIES, Japan) Hajime Akimoto, Jun-ichi Kurokawa (ACAP, Japan) Itsushi Uno (RIAM/Kyushu-U., Japan)

2 Background and aims (1) The rapid growth in many Asian countries in recent years led to the significant increase of urban, regional, and trans-boundary air pollution. (2) An understanding of long-term and future changes tropospheric ozone and its precursor emissions in Asia is an area of increasing scientific interest and political concern in Asia as well as global scale. (3) The aims of this work are; (a) to understand the recent trends of emissions for ozone precursors in Asia (b) to understand the long-term trends and future status of tropospheric ozone in Asia based on CTM modeling 2

3 3 Outline (1) Recent emissions in Asia (REAS 2.0) (2) Long-term trends of surface ozone (3) Future projection of surface ozone (4) Summary

4 4 Outline (1) Recent emissions in Asia (REAS 2.0) (2) Long-term trends of surface ozone (3) Future projection of surface ozone (4) Summary

5 Summary of REAS 2.0 We have updated the regional emission inventory in Asia (REAS 1.1) to the REAS 2.0. Item Description Years Spatial Resolution 0.25 degree 0.25 degree Temporal Resolution Monthly SO 2 NO x CO BC OC PM 10 PM 2.5 VOC NH 3 CH 4 CO 2 Combustion Non- Combustion Agriculture Fossil Fuel Biofuel Industrial Process Others Agricultural Field (Soil) Livestock 5

6 Temporal variations of emissions [Mt] NOx VOC Russia/ C Asia S Asia India SO PM 2.5 SE Asia E Asia Japan China

7 [Mt] % 80% 60% 40% 20% 0% NOx emissions in Asia Regional emissions Sectoral emissions Russia/ C Asia S Asia India SE Asia E Asia Japan China Domestic Others Transport Industry Power P. Growth in Asian NO x emissions from 2000 to 2008 were about 67%. NO x emissions in NE Asia were more than doubled during NO x emissions in SE Asia and India also increased rapidly (65% and 40%, respectively) due to the increase of energy consumption in power plants and road transport. Sectoral % of NOx in Asia increased in power plant and industry, while it decreased in transport and domestic sectors. 7

8 Recent trends of NOx emissions from space Annual trend of OMI/NO 2 for Inversed NOx emissions from satellite NO 2 VCD for China Consistent with EIs, but the trend of REAS is steeper. 1.5 (Irie et al., 2009) Chinese NOx emissions still continue to increase (except Beijing region). This feature is consistent with the trend of emission inventory. Ratio to emissions for Inversion REAS 1.1 REAS 2.0 INTEX-B Korea Inversion REAS 1.1 REAS Quite different after Japan Inversion REAS 1.1 REAS Completely consistent with REAS

9 [Mt] % 80% 60% 40% 20% VOC emissions in Asia Regional emissions Sectoral emissions Russia/ C Asia S Asia India SE Asia E Asia Japan China Miscellaneous Chemical Ind. Ext. & Proc. Paint Solvent Transport Growth in Asian VOC emissions from 2000 to 2008 were about 43%, which was lower than the value for NOx. VOC emissions in NE Asia increased by 55% during Sectoral % of VOC in Asia increased in solvent use (incl. for paint), while it decreased in stationary combustion. 0% Stationary comb. 9

10 NOx and VOC emissions in China, Korea, and Japan [Mt] China Japan (x5) R-Korea (x5) NOx [Mt] China Japan (X5) R-Korea (X5) VOC China s NO x emissions were more than doubled during However the increase rate became relatively smaller recently due to the penetration of low NO x boiler for coal-fired power plants and the reinforcement of vehicle emission control. China s VOC emissions increased by 68% during However the growth slowed down (or stopped in 2008?) due to fuel changes in residential sector and other factors. The increase rate for NOx was higher than the value for VOC, hence the VOC/NOx ratio was decreasing. Emission trends in Korea and Japan show the continuous decreasing or level off. 10

11 11 Outline (1) Recent emissions in Asia (REAS 2.0) (2) Long-term trends of surface ozone (3) Future projection of surface ozone (4) Summary

12 Outline of CMAQ long-term simulation Base-model CMAQ 4.4 Emission inventory (EI) REAS 1.1 TRACE-P biomass burning Meteorology RAMS with NCEP Global analysis Chemistry SAPRC99 scheme Initial & Lateral Boundary Conditions CHASER (Global CTM; Sudo et al., 2002) Fixed in climatological conc. Domain: 6400km 5600km (78 68 grids) Horizontal: 80km 80km Vertical: 14layer(RAMS=23 layer) up to 23km Model simulations (during ) EyyMyy: (year-by-year emission and met.) E00Myy (fixed emission of 2000) EyyM00 (fixed met. of 2000) China-off (zero emission for China) 12

13 Trends of springtime ozone from 1998 to 2007 Tanimoto, Ohara, and Uno (2009) GRL 13 obs. model In the free troposphere, the modeled trend is underestimated.

14 Trends of springtime ozone in western Japan from 1981 to 2005 (year-by-year emission and met.) (fixed emission of 2000) Kurokawa, Ohara et al., ACP (2009) Modeled O 3 in the EyyMyy case is consistent with the observed O 3. Inter-annual variation is caused by inter-annual variation of met. fields. Increased trend is caused by increased emissions of ozone precursors. 14

15 Changes of surface ozone in East Asia average average ppbv ppbv Ozone pollution is going from bad to worth. ppb Color : Increment of ozone (ppb) Line : Increased rate of ozone (% yr -1 ) (0.6% interval) 4~8ppbv up (+0.6~1.0% yr -1 ) >10ppbv up (>+2.0% yr -1 ) 15

16 16 Outline (1) Recent emissions in Asia (REAS 2.0) (2) Long-term trends of surface ozone (3) Future projection of surface ozone (4) Summary

17 Projected NOx emissions in Asia (RCP, GAINS, REAS1.0) NOx (Mt) Year REAS REAS(PSC) REAS(REF) REAS(PFC) Zhang et al. GAINS(Baseline) GAINS(Lower) RCP 8.5 RCP 6.0 RCP 4.5 RCP 2.6 In all scenarios, NOx increases before 2020, while their slope depend on the scenario. After 2020, all RCP scenarios predict a decrease, while GAINS predicts an increase. 17

18 Future changes of surface ozone between 2000 and PFC scenario O 3 (ppbv) REF scenario Under PSC scenario, the situation is almost same as 2000 level. Future ozone in East Asia depends on emission scenarios. Yamaji, Ohara et al. (2008) JGR 18

19 Projected tropospheric ozone in 2050 based on RCP scenarios Emission trends from four RCP scenarios during (NOx) (VOC) Modeling System RCP Emissions Chem. Emissions CMAQ v4.7 CHASER IC, BC Met. Meteorology WRF v3.2 Both NOx and VOC emissions in every region tend to decrease (or level off) after

20 Projected NOx emissions and surface ozone for 2050 based on the RCP scenarios (Mid-term projection) ΔNOx emissions (= ) Based on RCP scenarios RCP2.6 Surface ΔO 3 (= ) predicted by CHASER (Kawase et al., 2011) GgN/yr (ppbv) RCP8.5 NOx(TgN/yr) RCP RCP RCP

21 21 Summary We have updated the regional emission inventory in Asia (REAS 1.1) to the REAS 2.0 which covers during The Asian emissions of ozone precursors increased in the last decade. However, the growth of China s emissions, which is a driving force of emission growth in Asia, slowed down recently due to a series of reinforcement of emission control. In East Asia, the tropospheric ozone increased in the last three decades due to the growth of emissions of ozone precursors. In future, the ozone change strongly depends on the emission scenario.