1 Emission Control Impact on Ozone Levels from mobile and point sources in southern China Ying Li, Alexis Lau, Jimmy Fung

2 Exceedance seen at all sites – even urban ones

3 Emission update and Model verification

4 MODELING SYSTEM (recently update) Meteorological MM5v3.6.3 Emission Processor SMOKE Gridded Emission INTEX-B Air Quality Model CMAQ 4.6 Air Quality Model CAMx 5.10

5 27km 9km 3km ParameterValue ProjectionLambert-Conformal Alpha15 degrees North Latitude Beta40 degrees North Latitude x center114 degrees East Longitude y center28.5 degrees North Latitude Coordinate system projection parameters for the PATH Modelling system.

6 INTEX-B D1

7 Spatial allocation (srg) of emissions 1 New area Old area New mobile Old mobile

8 Spatial allocation (srg) of emissions 2 New marine Old marine New SZ area Old SZ area

9 Station: Lau Fau Shan

10 Simulation of ozone maxima is improved (b) Luhu site of GZ Donghu site of Jiangmen Simulation of ozone maxima is improved

11 Temporal trend of Ozone- NOx-VOC sensitivity

12 O3 variation caused by reducing 30% NOx emission of all emission source O3_perturbation case - O3_base case >0 (red)  VOC-sensitive <0 (blue)  NOx-sensitive 8 AM VOC limited

13 O3 variation caused by reducing 30% NOx emission of all emission source O3_perturbation case - O3_base case >0 (red)  VOC-sensitive <0 (blue)  NOx-sensitive 2 PM VOC NOX limited

14 Base case: O3 concentration at 2PM

15 Feasible ozone control strategies, and evaluation Mobile : NOx & VOC Point : NOx Area : VOC

16 减排措施 适合范围 目标污染物 可削减 % 汽油 小客 汽油 小货 汽油 大客 柴油 小货 柴油 大客 柴油 大货 摩托 车 a. 推行国Ⅲ标准 √√√√√√√ NOx ＆ VOC 11.1% b. 机动车限行 √√√√√ NOx ＆ VOC 5.9% c. 推行国Ⅳ标准 √√√√√√√ NOx ＆ VOC 12.9% 其它 √√√√√√ 3 ～ 4% 总合～ 30% 交通源及点源控制措施及减排效率 减排措施 适用范围目标污染物可 削减 % 大电厂小电厂工业源 低氮燃烧 √√√ NOx20-60% SNCR √√ NOx40% SCR √√ NOx80%

17 Design of Control Scenarios (1) Reducing both VOC and NOx emissions of PRD mobile source by 50%; (2) Reducing VOC emissions of PRD mobile and area source by 50% (less feasible); (3) Reducing NOx emission from point source by 50%; (4) Reducing NOx emission from point source by 85%; (5) case 1 + case 3

18 What’s the mobile control impact on ozone concentration?

19 GZ city averaged effect FS city averaged effect GZ luhu site FS huijingcheng site

20 What’s the point source control impact on ozone concentration?

21 The O3 time series of NOx/VOCs zero impact of GZ city average

22 Autumn case :O 3 and O 3 variation by reducing 50% NOx from point source Color: Base case Contour: black: O3 decr. white: O3 incr Color: with NOX control Contour: black: O3 decr. white: O3 incr

23 Autumn case :O 3 and O 3 variation by reducing 50% NOx from point source Color: Base case Contour: black: O3 decr. white: O3 incr Color: with NOX control Contour: black: O3 decr. white: O3 incr

24 Summer case :O 3 and O 3 variation by reducing 50% NOx from point source Color: Base case Contour: black: O3 decr. white: O3 incr Color: with NOX control Contour: black: O3 decr. white: O3 incr

25 O 3 Frequency distribution of base case and 4 NOx reduction cases

26 CaseSource category Emission type and reduction Control feasibility D3 total O3 variation (ppb) 1PRD&HK On-road mobile NOx 50% VOC 50% high PRD&HK On-road mobile, area VOC 50%low PRD&HK Point sourceNOx 50%high PRD&HK Point sourceNOx 85%high PRD&HK Point source, on-road mobile NOx(50%pt 50%mv) VOC 50%mv high83070 Comparison of control strategies VOC control almost always lead to ozone decrease NOx control lead to ozone increase at the locations with low concentration, and decrease at locations with high concentration.

27 Summary of feasible O3 Control strategy priority of the autumn case Reduce PRD 50% traffic is the most effective control strategy Reduce PRD 50% VOCs from traffic and area has similar effect in GZ The large point sources are not the major sources for these ozone increased, but lead to NOx-titration effect. The contribution from these large point sources is notable in the areas further downwind. The sources that generate the elevated ozone in the upwind areas to the point sources and the point sources that positively contribute to the ozone formation should be considered as the real contributing sources for the highest ozone concentration.