natividad urquizo, w. pugsley, d. spitzer* & m. robinson city of ottawa *a-maps environmental...
TRANSCRIPT
Natividad Urquizo, W. Pugsley, D. Spitzer* & M. RobinsonCity of Ottawa*A-MAPS Environmental
Mapping Small Scale Air Mapping Small Scale Air Pollution Distribution Pollution Distribution using Satellite using Satellite Observations in a Large Observations in a Large Canadian CityCanadian City
Mapping Small Scale Air Mapping Small Scale Air Pollution Distribution Pollution Distribution using Satellite using Satellite Observations in a Large Observations in a Large Canadian CityCanadian City
2
Project LocationProject Location
3
Using satellite data map pollution concentrations for 5,600 km2 area.
Identify “hot spots” spatially at 1-km2 resolution hour by hour for the following air contaminants:
Nitrogen oxides (NO, NO2, NOx) Carbon monoxide Ground level ozone PM2.5
ObjectivesObjectives
4
Data sourcesData sources Ground level air quality monitors
NAPS permanent stations (3) One Quebec station (PM2.5 & O3) Mobile labs for 8 locations
Aura satellite data (13 x 24 km resolution) Air and ground transportation data Meteorological data Land use data Data processing by A-MAPS Environmental
Inc.
5
Ground Level Monitoring LocationsGround Level Monitoring Locations
6
Total Mapping AreaTotal Mapping Area
7
Data IntegrationData Integration Time of satellite overpass:
Determine grid point value at the centre of each satellite pixel
Used Kriging to interpolate with 1-km2
Smooth ground data with 3-hour running average
Calculate field ratio of ground level measurement to satellite
Calibrate pixel with spatial average of field ratio
8
Data Integration … continueData Integration … continue Calculate hourly concentrations from
interpolation in time using closest ground station
Modify values using traffic emissions and the Green function, advection and diffusion equations
Finally calibrate 1-km values from measured concentration at nearest emission source
9
Confirm previous findingsConfirm previous findings
Pollutants below hourly Canada Wide Standards 95% of the time
Pollution is locally produced and result of trans-boundary pollution
Smog events not restricted to summer days (December 13-14th)
Major roads exhibit more pollution at peak hour
10
High Pollution NodesHigh Pollution Nodes
11
Transportation Impact on NO2 ExceedancesTransportation Impact on NO2 Exceedances
NO2 > 50ppb 2007-12-10 - 2007-12-12
12
New Findings: NO2 west-east gradientNew Findings: NO2 west-east gradient
13
O3: West-East GradientO3: West-East Gradient
14
PM2.5: west-east gradientPM2.5: west-east gradient
15
More new findingsMore new findings
Origin of worst episodes: From the east (Montreal, Sept 14th) From the south (Ohio Valley, Sep 21st
& 25th) Locally produced (Dec 13th)
16
September 14th 2007 Episode Montreal InfluenceSeptember 14th 2007 Episode Montreal Influence
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
Confidence levelConfidence level
Pollutant STD (Map) STD (MOE)
CO (ppm) 0.1 - 0.18 0.11 – 0.14
NO (ppb) 5 - 9 8.5 – 8.74
NO2 (ppb) 5 - 10 10.65 – 11.5
NOx (ppb) 12 - 18 17 – 17.5
O3 (ppb) 11 - 14 13 – 13.78
PM2.5 (ug/m3) 6 5.84 – 6.75
38
Single pixel comparisonSingle pixel comparison
Orleans site measurements using mobile lab and results of modelling shows good cross-validation
Pollutant
STD
CO 0.007 (ppm)
NO 2.4 (ppb)
NO23.0 (ppb)
NOx4.4 (ppb)
O33.8 (ppb)
PM2.53.3 (ug/m3)
39
Downtown NOx concentrationsDowntown NOx concentrations
Peak hour pollution lasts 4 hours or less
Three-hour running average smoothes traffic effect
City Hall 2008-05-08
0
10
20
30
40
50
1 4 7
10
13
16
19
22
25
Hour
NO
x p
pb
NOx
NO2
NO
S_NOx
40
Relative Exposure Concentration of PM and Influence of traffic Krzyzanowski et al (2005) http://tinyurl.com/258hql
Relative Exposure Concentration of PM and Influence of traffic Krzyzanowski et al (2005) http://tinyurl.com/258hql
Shows 24 hour traffic generated exposure for PM2.5
Light pink: regional background, light blue: urban ambient and peaks in traffic
Exposure while commuting represents half of exposure to PM from traffic
41
Major Origin-Destination Flows – Morning Trips 2005Ref:http://tinyurl.com/6vlrcf
Major Origin-Destination Flows – Morning Trips 2005Ref:http://tinyurl.com/6vlrcf
42
NO2 hourly un-smooth mapsNO2 hourly un-smooth maps
43
NO2 October 4th, 2007 at 2 h
44
NO2 October 4th, 2007 at 3 h
45
NO2 October 4th, 2007 at 4 h
46
NO2 October 4th, 2007 at 5 h
47
NO2 October 4th, 2007 at 6 h
48
NO2 October 4th, 2007 at 7 h
49
NO2 October 4th, 2007 at 8 h
50
NO2 October 4th, 2007 at 9 h
51
NO2 October 4th, 2007 at 10 h
52
NO2 October 4th, 2007 at 11 h
53
NO2 October 4th, 2007 at 12 h
54
NO2 October 4th, 2007 at 13 h
55
NO2 October 4th, 2007 at 14 h
56
NO2 October 4th, 2007 at 15 h
57
NO2 October 4th, 2007 at 16 h
58
NO2 October 4th, 2007 at 17 h
59
NO2 October 4th, 2007 at 18 h
60
NO2 October 4th, 2007 at 19 h
61
NO2 October 4th, 2007 at 20 h
62
NO2 October 4th, 2007 at 21 h
63
NO2 October 4th, 2007 at 22 h
64
NO2 October 4th, 2007 at 23 h
65
NO2 October 5th, 2007 at 0 h
66
Public Health Policy ChallengesPublic Health Policy Challenges
Answers required: What sort of spatial accuracy and temporal
frequency for air pollutant concentrations is needed to comply with public health requirements?
What response or action is needed at urban “hotspots” for short duration high intensity events or for extended events?
What threshold for each pollutant should be established as a trigger for corrective action?
67
Technical Breach Areas – City of Yorkhttp://www.york.gov.uk/environment/airquality/Tech_breach.pdf
Technical Breach Areas – City of Yorkhttp://www.york.gov.uk/environment/airquality/Tech_breach.pdf
Sample of roads with pollution above standard
Ottawa/Gatineau exhibit similar “hot spots” during peak hours
Future AQ modelling at neighbourhood level
68
AcknowledgementsAcknowledgements This mapping project was possible with funding from:
GeoConnections (Natural Resource Canada) The Ottawa International Airport The City of Ottawa
In kind contributions from: Transport Canada Environment Canada Ontario Ministry of the Environment (MOE) Ministère du Développement durable, de l'Environnement et des
Parcs (of the province of Quebec) and Health Canada
A-MAPS Environmental was contracted for this project
