Title: COMPARISON OF LINK-BASED AND SMOKE PROCESSED MOTOR VEHICLE EMISSIONS OVER THE GREATER TORONTO AREA
1 - COMPARISON OF LINK-BASED AND SMOKE PROCESSED
MOTOR VEHICLE EMISSIONS OVER THE GREATER TORONTO
AREA - Junhua Zhang1, Craig Stroud1, Michael D. Moran1,
Brett Taylor2, and David Lavoué3 - Air Quality Research Division, Environment
Canada, Toronto, Ontario, Canada - Pollutant Inventories and Reporting Division,
Environment Canada, Gatineau, Quebec, Canada - Golder Associates Ltd., 2390 Argentia Road,
Mississauga, Ontario, Canada
11th Annual CMAS Conference, Chapel Hill, NC,
Oct. 15-17, 2012
2 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
3Objective 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
4Emissions Processing by SMOKE (1)
Zhang et al., 2012, 20th International Emission
Inventory Conference
AQ Model Inputs
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
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
Right Time Right Location Right Species Right
Amount
5Emissions Processing by SMOKE (2)
Weekly Profiles for On-Road Mobile Emissions
Four Weekly Profiles from EPA
6Emissions Processing by SMOKE (3)
Diurnal Profiles for On-Road Mobile Emissions
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 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
Urban Roads 6 Road Classes
Rural Roads 6 Road Classes
Heavy Duty Vehicles All Roads
7Spatial Surrogates for On-Road Mobile Emissions
BAQS-Met 2.5km AURAMS Domain
Emissions Processing by SMOKE (4)
Based on National Road Network Population
Urban Local Road
Urban Secondary Road
Urban Primary Road
Rural Secondary Road
Rural Primary Road
Rural Local Road
8Link-Based Emissions Processing (1)
- 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
- Emission Factors
- Vehicle Fleet Information Vehicle
- Type, Age Distribution, Speed
- Fuel Types
- Type of Emissions Exhaust,
- Evaporative, Tire Dust, Brake Dust
- Meteorology
9Link-Based Emissions Processing (2)
Kanaroglou et al., 2009, Final Report to
Environment Canada
Traffic Flow Software TRAFFIC, Centre for
Spatial Analysis (CSpA), McMaster University,
Canada Emission Factors MOBILE6.2C, Canadian
Version of US EPA MOBILE6.2
GTA Road Network
Traffic Analysis Zones (1,316)
Source Kanaroglou et al., 2009, Final Report to
Environment Canada
10Link-Based Emissions Processing (3)
Link-based emissions were mapped to the same
AURAMS 2.5km domain to compare with SMOKE
processed emissions
11 Temporal Comparisons
Time series of domain total NO and CO emissions
during a week in July
- Link-based emissions have significant rush hour
peaks - Rush hour peaks are not clear for SMOKE-processed
emissions, especially NO - SMOKE-processed emissions are larger than
link-based emissions mid-day, night, and
weekends - Vehicles from outside the GTA were not considered
in the link-based emissions
12 Spatial Comparisons (1)
Link-based Highways vs. SMOKE-Processed Primary
Roads
Link-based Highways
SMOKE-Processed Primary Roads
Domain Average Diurnal Variation
- Link-based highways correspond reasonably well
with SMOKE primary road - Much higher emissions from SMOKE
13 Spatial Comparisons (2)
Link-based Arterial Roads vs. SMOKE-Processed
Secondary Roads
Link-based Arterial Roads
SMOKE-Processed Secondary Roads
Domain Average Diurnal Variation
- Much lower emissions from SMOKE
- Link-based emissions are concentrated in the
downtown area, which is reasonable - SMOKE surrogate based on road length and of
lanes
14 Spatial Comparisons (3)
Link-based Pseudo Links vs. SMOKE-Processed Local
Roads
Link-based Pseudo Links
SMOKE Processed Local Roads
Domain Average Diurnal Variation
- SMOKE-processed emissions compare reasonably well
with link-based emissions
15Improvements 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 Class Original Surrogate ( EPA) Revised Surrogate
Urban Interstate Primary Road Primary Road
Urban Freeway Primary Road Primary Road
Urban Principal Arterial Primary Road Primary Road
Urban Minor Arterial Primary Road Secondary Road
Urban Collector Secondary Road Secondary Road
Urban Local Local Road Local Road
Sensitivity Test Assigning Urban Minor Arterial
Road to Secondary Road surrogate
16Improvements to SMOKE Processing of On-road
Emissions (2)
Sensitivity to Surrogate Assignment
17Improvements 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
Secondary Road Surrogate from Link-based Emissions
Original Secondary Road Surrogate
18 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
19AcknowledgementsThanks 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 Temporal Comparisons
Time Series of NO and CO emissions during a week
in July, grid cell in Downtown