Modelling the impact of three sets of future vehicle emission standards on PMconcentrations in the Lower Fraser Valley

Weimin Jiang,

Éric Giroux, Dazhong Yin, and Helmut Roth

National Research Council of Canada

2004 Models-3 Conference, October 18-21, 2004 2

Outline

Introduction

The modelling scenarios

Impact of the emission standards on PM2.5

Other impacts

Summary and discussions

2004 Models-3 Conference, October 18-21, 2004 3

Introduction

Objective:

To study the impact of three sets of future vehicle emission standards on ambient PM concentrations in the Lower Fraser Valley.

The modelling system:

• CMAQ version 4.1 with NRC’s modifications

• SMOKE v1.4&2.0; MM5 v3; MCIP v2.2

• NRC’s PMx post-processor (for calculating PMx,ca)

Modelling domain

Nested 15- and 5-km domains focused on Lower Fraser Valley

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Modelling domain

Pacific Ranges

Harrison Lake

CANADAUS

Bellingham

Burlington

VancouverStra ight o f Georg ia

Vancouver Is land

PIM E3

LAN G 3

W H R O 3 C LBR 3

C H IL3

AG G A3U N BC 3

Analysis is focused on the 5 km resolution inner domain.

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Scenarios: BA, FBA, FNM

1. BA: the Pacific ’93 base case scenario

0:00 July 31 – 24:00 August 7, 1993;

2. FBA: the 2020 future base case scenario

BA projected to 2020 without considering the three sets of emission standards to be modelled;

3. FNM: the 2020 future no mobile scenario

FBA – mobile source emissions

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4. ES: the emission standards scenario

FBA + three sets of vehicle emission standards:

1) The light–duty Tier 2 vehicle emission standards to be implemented from 2004;

2) The heavy–duty vehicle NMHC and NOx emission standards to be implemented from 2004;

3) The heavy duty vehicle NOx and PM emissions and low sulphur on–road diesel standards to be implemented from 2007.

Scenario: ES

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Scenario emissions

NOx

0

1000

2000

3000

4000B

A

FB

A

FN

M ES

VOC

0

3000

6000

9000

12000

BA

FB

A

FN

M ES

SOx

0

300

600

900

1200

BA

FB

A

FN

M ES

0

1

2

3

4

5

6

7

8

1

Mobile On-Road CANADA Mobile On-Road USAFugitive Dust Mobile Off-RoadArea PointBiogenic

NH3

0

200

400

600

800

1000

BA

FB

A

FN

M ES

PM2.5

0

100

200

300

400

500

BA

FB

A

FN

M ES

PM10

0

200

400

600

800

1000

BA

FB

A

FN

M ES

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Spatial impact: episode-average PM2.5

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Spatial impact: on-road mobile contributions to episode-average PM2.5

A Mobile–Impacted Area (MIA): on–road mobile

sources contribute at least 0.5 g m-3 to episode–

average PM2.5

% reduction in on–road mobile source

contributions to PM2.5 in the MIA

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Spatial impact: maximum 1-hour PM2.5

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Temporal impact: domain-average PM2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

0:00 7/31

0:00 8/1

0:00 8/2

0:00 8/3

0:00 8/4

0:00 8/5

0:00 8/6

0:00 8/7

0:00 8/8

Pacific Daylight Time, July 31 to aug 7, 1993

Ab

s. D

iff.

[ g

m-3

]

-8

-6

-4

-2

0

2

4

6

Rel

. D

iff.

[%

]

Absolute DifferenceRelative Difference

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Significantly impacted location and time

The emission standards tend to cause more significant PM2.5 reductions in places where maximum 1–hour concentrations of PM2.5 are high or the incremental contributions of on–road mobile sources to ambient PM2.5 are more significant.

In general, the PM2.5 reductions due to the emission standards also tend to be more significant at the hours when ambient PM2.5 concentrations are high.

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Magnitude of the impact

Unit Most + Most - Average

g m-3 0.3 -1.9 -0.1

% 1.9 -15.1 -1.2

g m-3 -0.1 -1.9 -0.5

% -10.8 -76.8 -64.0

g m-3 7.4 -11.8 -2.1

% 17.9 -25.2 -3.7

g m-3 0.3 -1.9 -0.1

% 3.9 -6.2 -0.7

Maximum 1-hour PM2.5

Hourly domain-average PM2.5

Impact

Episode-average PM2.5

Mobile contributions to episode-average PM2.5

in the MIA

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Other impacts • Impact of emission projections from BA to FBA;

• Cumulative impact of emission changes from BA to ES impact on (ANH4, ANO3, ASO4), and (AORGPA, AORGA, AORGB, AORG);

• Of note: 1. Interconnected impact of NOx and SOx

emission reductions and NH3 emission increases;

2. Indirect impact of NOx emission reductions on the organic PM groups via O3 increases in some areas;

3. Higher biogenic organic PM species concentrations than anthropogenic organic species due to dominant biogenic VOC emissions.

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Summary and discussions

The emission standards will be effective in controlling on–road mobile source contributions to ambient PM2.5 levels;

The average impact on ambient PM2.5 will vary noticeably with location and time:

• Reductions will be most evident where maximum 1–hour PM2.5 concentrations are high or on–road mobile source contributions are significant, and when domain–average ambient PM2.5 concentrations are high.

• Changes in other areas and hours are expected to be minor, and may dilute or offset the positive impact of the emission standards when averaged over the whole domain or episode;

Uncertainties in PM science and in emissions;

Regional nature of the results.

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Acknowledgements

The Pollution Data Branch, Pacific & Yukon Region, and the Transportation Systems Branch of Environment Canada, Vancouver Regional District (GVRD):

Raw emission inventory data and assistance in modeling and processing the emission data ;

GVRD/Fraser Valley Regional District (FVRD), SENES Consulting Ltd./Air Improvement Resources Inc:

Emission projection factors;

US EPA and CMAS:

The original Models-3/CMAQ system;

Program of Energy Research and Development (PERD), Natural Resources Canada:

Funding support.

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