1

Emission Control Impact on Ozone Levelsfrom mobile and point sources in southern China

Ying Li, Alexis Lau, Jimmy Fung

2Exceedance seen at all sites – even urban ones

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Emission updateEmission update

andand

Model verificationModel verification

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MODELING SYSTEM (recently update)

Meteorological

MM5v3.6.3

Emission Processor

SMOKE 2.4

+Gridded Emission

INTEX-B

Air Quality Model

CMAQ 4.6

Air Quality Model

CAMx 5.10

5-522 -468 -414 -360 -306 -252 -198 -144 -90 -36 18 72 126 180 234 288 342

-967.5

-913.5

-859.5

-805.5

-751.5

-697.5

-643.5

-589.5

-535.5

-481.5

-427.5

-373.5

-319.5

-2403 -1971 -1539 -1107 -675 -243 189 621 1053 1485 1917 2349-1876.5

-1660.5

-1444.5

-1228.5

-1012.5

-796.5

-580.5

-364.5

-148.5

67.5

283.5

499.5

715.5

931.5

1147.5

1363.5

1579.5

1795.5

-291 -264 -237 -210 -183 -156 -129 -102 -75 -48 -21 6 33 60 87 114 141-754.5

-727.5

-700.5

-673.5

-646.5

-619.5

-592.5

-565.5

-538.5

-511.5

-484.5

-457.5

-430.5

27km

9km

3km

Parameter Value

Projection Lambert-Conformal

Alpha 15 degrees North Latitude

Beta 40 degrees North Latitude

x center 114 degrees East Longitude

y center 28.5 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

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Spatial allocation (srg) of emissions 2

New marine

Old marine

New SZ area

Old SZ area

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Station: Lau Fau Shan

10

Simulation of ozone maxima

is improved

Luhu site of GZ

Donghu site of Jiangmen

Simulation of ozone maxima

is improved

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Temporal trend of Ozone-NOx-VOC sensitivity

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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

VOClimited

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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

VOCNOX

limited

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Base case: O3 concentration at 2PM

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Feasible ozone control strategies, and evaluation

Mobile : NOx & VOCPoint : NOxArea : VOC

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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 √ √ √ NOx 20-60%

SNCR √ √ NOx 40%

SCR √ √ NOx 80%

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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

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What’s the mobile control impact on ozone concentration?

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GZ city averaged effect FS city averaged effect

GZ luhu site FS huijingcheng site

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What’s the point source control impact on ozone

concentration?

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

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Autumn case :O3 and O3 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

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Autumn case :O3 and O3 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

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Summer case :O3 and O3 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

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O3 Frequency distribution of base case and 4 NOx reduction cases

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Case Source categoryEmission type and reduction

Controlfeasibility

D3 total O3 variation (ppb)

1 PRD&HK On-road mobileNOx 50%VOC 50%

high 34820

2PRD&HK On-road

mobile, areaVOC 50% low 16740

3 PRD&HK Point source NOx 50% high 19470

4 PRD&HK Point source NOx 85% high 43430

5PRD&HK Point source,

on-road mobileNOx(50%pt 50%mv)

VOC 50%mvhigh 83070

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.

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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 GZThe 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.