1. COMPARISON OF LINK-BASED AND SMOKE PROCESSED MOTOR VEHICLE EMISSIONS OVER THE GREATER TORONTO AREA Junhua Zhang 1, Craig Stroud 1, Michael D. Moran 1, Brett Taylor 2, and David Lavoué 3 1. Air Quality Research Division, Environment Canada, Toronto, Ontario, Canada 2. Pollutant Inventories and Reporting Division, Environment Canada, Gatineau, Quebec, Canada 3. Golder Associates Ltd., 2390 Argentia Road, Mississauga, Ontario, Canada 11 th Annual CMAS Conference, Chapel Hill, NC, Oct. 15-17, 2012

2. Page 2 – October 6, 2015 OVERVIEW: Introduction On-road mobile emissions processing by SMOKE Link-based on-road mobile emissions processing Temporal and spatial comparisons between SMOKE-processed and link-based on-road emissions Potential improvements to representation of on-road emissions for air quality modelling, especially for high-resolution modeling

3. Page 3 – October 6, 2015 Objective of this study:  Prepare on-road mobile emissions for high resolution (~1km) air quality modeling for the Greater Toronto Area (GTA) Largest urban area in Canada, with a population of 5.5 million in 2011 Major highways that link cities in the U.S. and Canada Busy local arterial network

4. Page 4 – October 6, 2015 Emissions Processing by SMOKE (1): Canadian On-Road Emissions Inventory Temporal: Monthly Totals Spatial: Mostly Provincial Totals Source Category: By Vehicle Type and by Road Type Pollutants: PM, VOC, NOx, etc. SMOKE Temporal ( Weekly & Diurnal Profiles ): Hourly Spatial ( Spatial Surrogates ): Each Grid Cell, e.g., 42 km, 15 km, 2.5 km Chemical Species ( Chemical Speciation Profiles ): PM Species: Sulphate, Nitrate, Ammonium, Elemental Carbon, Organic Matter, Crustal Material VOC Species: Propane, Alkenes, Alkanes, Toluene, Isoprene, etc. NOx Species: NO2, NO AQ Model Inputs Right Time Right Location Right Species Right Amount Zhang et al., 2012, 20th International Emission Inventory Conference

5. Page 5 – October 6, 2015 Emissions Processing by SMOKE (2): Four Weekly Profiles from EPA: Weekly Profiles for On-Road Mobile Emissions:

6. Page 6 – October 6, 2015 Emissions Processing by SMOKE (3): 12 profiles for Light Duty Vehicles from EPA for 12 Road Classes 1 derived profile from FEVER Study for Heavy Duty Vehicles for All Roads Urban Roads: 6 Road Classes Heavy Duty Vehicles: All Roads Rural Roads: 6 Road Classes Urban Interstate Urban Freeway Urban Principal Arterial Urban Minor Arterial Urban Collector Urban Local Rural Interstate Rural Principal Arterial Rural Minor Arterial Rural Major Collector Rural Minor Collector Rural Local Diurnal Profiles for On-Road Mobile Emissions

7. Page 7 – October 6, 2015 Spatial Surrogates for On-Road Mobile Emissions: BAQS-Met 2.5km AURAMS Domain Based on National Road Network & Population Urban Local RoadUrban Secondary RoadUrban Primary Road Rural Secondary Road Rural Primary Road Rural Local Road Emissions Processing by SMOKE (4):

8. Page 8 – October 6, 2015 Traffic Flow:  Street Network  Traffic Analysis Zones (TAZs)  Vehicle Specific Hourly Origin- Destination Matrices  Vehicle Specific Hourly Traffic Flow on each segment of the road On-Road Mobile Emissions:  HC, NOX, CO, PM, Toxics, etc.  Hourly on Each Road Segment (link)  By Vehicle Type or Total Link-Based Emissions Processing (1): Emission Factors:  Vehicle Fleet Information: Vehicle Type, Age Distribution, Speed  Fuel Types  Type of Emissions: Exhaust, Evaporative, Tire Dust, Brake Dust  Meteorology

9. Page 9 – October 6, 2015 Link-Based Emissions Processing (2): Kanaroglou et al., 2009, Final Report to Environment Canada GTA Road Network Traffic Analysis Zones (1,316) Traffic Flow Software: TRAFFIC, Centre for Spatial Analysis (CSpA), McMaster University, Canada Emission Factors: MOBILE6.2C, Canadian Version of US EPA MOBILE6.2 Source: Kanaroglou et al., 2009, Final Report to Environment Canada

10. Page 10 – October 6, 2015 Link-Based Emissions Processing (3): Link-based emissions were mapped to the same AURAMS 2.5km domain to compare with SMOKE processed emissions

11. Page 11 – October 6, 2015 Temporal Comparisons: Time series of domain total NO and CO emissions during a week in July 1)Link-based emissions have significant rush hour peaks 2)Rush hour peaks are not clear for SMOKE- processed emissions, especially NO 3)SMOKE-processed emissions are larger than link-based emissions: mid-day, night, and weekends 4)Vehicles from outside the GTA were not considered in the link-based emissions

12. Page 12 – October 6, 2015 Spatial Comparisons (1): Link-based Highways vs. SMOKE-Processed Primary Roads Link-based HighwaysSMOKE-Processed Primary Roads Domain Average Diurnal Variation 1)Link-based highways correspond reasonably well with SMOKE primary road 2)Much higher emissions from SMOKE

13. Page 13 – October 6, 2015 Spatial Comparisons (2): Link-based Arterial Roads vs. SMOKE-Processed Secondary Roads Link-based Arterial RoadsSMOKE-Processed Secondary Roads Domain Average Diurnal Variation 1)Much lower emissions from SMOKE 2)Link-based emissions are concentrated in the downtown area, which is reasonable 3)SMOKE surrogate based on road length and # of lanes

14. Page 14 – October 6, 2015 Spatial Comparisons (3): Link-based Pseudo Links vs. SMOKE-Processed Local Roads Link-based Pseudo LinksSMOKE Processed Local Roads Domain Average Diurnal Variation 1)SMOKE-processed emissions compare reasonably well with link-based emissions

15. Page 15 – October 6, 2015 Improvements to SMOKE Processing of On-road Emissions (1): Sensitivity to Surrogate Assignment The issue: Compared with link-based emissions, too much emissions on primary roads, too little on secondary roads Inventory Road ClassOriginal Surrogate ( EPA) Revised Surrogate Urban InterstatePrimary Road Urban FreewayPrimary Road Urban Principal ArterialPrimary Road Urban Minor ArterialPrimary RoadSecondary Road Urban CollectorSecondary Road Urban LocalLocal Road Sensitivity Test: Assigning Urban Minor Arterial Road to Secondary Road surrogate

16. Page 16 – October 6, 2015 Improvements to SMOKE Processing of On-road Emissions (2): Sensitivity to Surrogate Assignment

17. Page 17 – October 6, 2015 Improvements to SMOKE Processing of On-road Emissions (3): Build a secondary road surrogate based on link-based emissions The issue: SMOKE secondary road surrogate is based on road length and number of lanes, without considering traffic volume Original Secondary Road Surrogate Secondary Road Surrogate from Link-based Emissions

18. Page 18 – October 6, 2015 Conclusions:  Significant differences between SMOKE-processed and link-based mobile emissions in the Greater Toronto Area, both temporally and spatially  During weekdays, the link-based emissions have significant peaks during both morning and afternoon rush hours. The peaks are not so clear for SMOKE processed emissions, especially for NO emissions  For SMOKE, assignment of spatial surrogates may need to be adjusted  The SMOKE secondary road surrogate needs to be improved to reflect the variation of traffic volumes in the city  Emissions from vehicles coming from outside the city need to be included in the link-based emissions inventory to be suitable for AQ modeling studies  Emission factors from MOVES, instead of MOBILE, should be used in the future for link-based emissions processing

19. Acknowledgements Thanks to the project team in the Centre for Spatial Analysis (CSpA), McMaster University for processing the link-based emissions Thanks to our colleagues in Environment Canada for their helpful discussions

20. Page 20 – October 6, 2015 Temporal Comparisons: Time Series of NO and CO emissions during a week in July, grid cell in Downtown