Presentation on theme: "Natividad Urquizo, W. Pugsley, D. Spitzer* & M. Robinson City of Ottawa *A-MAPS Environmental Mapping Small Scale Air Pollution Distribution using Satellite."— Presentation transcript:
Natividad Urquizo, W. Pugsley, D. Spitzer* & M. Robinson City of Ottawa *A-MAPS Environmental Mapping Small Scale Air Pollution Distribution using Satellite Observations in a Large Canadian City
3 l Using satellite data map pollution concentrations for 5,600 km 2 area. l Identify hot spots spatially at 1-km 2 resolution hour by hour for the following air contaminants: l Nitrogen oxides (NO, NO 2, NOx) l Carbon monoxide l Ground level ozone l PM 2.5 Objectives
4 Data sources l Ground level air quality monitors l NAPS permanent stations (3) l One Quebec station (PM 2.5 & O 3 ) l Mobile labs for 8 locations l Aura satellite data (13 x 24 km resolution) l Air and ground transportation data l Meteorological data l Land use data l Data processing by A-MAPS Environmental Inc.
7 Data Integration l Time of satellite overpass: l Determine grid point value at the centre of each satellite pixel l Used Kriging to interpolate with 1-km 2 l Smooth ground data with 3-hour running average l Calculate field ratio of ground level measurement to satellite l Calibrate pixel with spatial average of field ratio
8 Data Integration … continue l Calculate hourly concentrations from interpolation in time using closest ground station l Modify values using traffic emissions and the Green function, advection and diffusion equations l Finally calibrate 1-km values from measured concentration at nearest emission source
9 Confirm previous findings l Pollutants below hourly Canada Wide Standards 95% of the time l Pollution is locally produced and result of trans-boundary pollution l Smog events not restricted to summer days (December 13-14 th ) l Major roads exhibit more pollution at peak hour
37 Confidence level PollutantSTD (Map)STD (MOE) CO (ppm)0.1 - 0.180.11 – 0.14 NO (ppb)5 - 98.5 – 8.74 NO 2 (ppb)5 - 1010.65 – 11.5 NO x (ppb)12 - 1817 – 17.5 O 3 (ppb)11 - 1413 – 13.78 PM 2.5 (ug/m 3 )65.84 – 6.75
38 Single pixel comparison l Orleans site measurements using mobile lab and results of modelling shows good cross- validation PollutantSTD CO 0.007 (ppm) NO 2.4 (ppb) NO 2 3.0 (ppb) NO x 4.4 (ppb) O3O3 3.8 (ppb) PM 2.5 3.3 (ug/m 3 )
39 Downtown NOx concentrations l Peak hour pollution lasts 4 hours or less l Three-hour running average smoothes traffic effect
40 Relative Exposure Concentration of PM and Influence of traffic Krzyzanowski et al (2005) http://tinyurl.com/258hql http://tinyurl.com/258hql Relative Exposure Concentration of PM and Influence of traffic Krzyzanowski et al (2005) http://tinyurl.com/258hql http://tinyurl.com/258hql l Shows 24 hour traffic generated exposure for PM2.5 l Light pink: regional background, light blue: urban ambient and peaks in traffic l Exposure while commuting represents half of exposure to PM from traffic
41 Major Origin-Destination Flows – Morning Trips 2005 Ref:http://tinyurl.com/6vlrcf
66 Public Health Policy Challenges l Answers required: l What sort of spatial accuracy and temporal frequency for air pollutant concentrations is needed to comply with public health requirements? l What response or action is needed at urban hotspots for short duration high intensity events or for extended events? l What threshold for each pollutant should be established as a trigger for corrective action?
67 Technical Breach Areas – City of York http://www.york.gov.uk/environment/airquality/Tech_breach.pdf l Sample of roads with pollution above standard l Ottawa/Gatineau exhibit similar hot spots during peak hours l Future AQ modelling at neighbourhood level
68 Acknowledgements l This mapping project was possible with funding from: l GeoConnections (Natural Resource Canada) l The Ottawa International Airport l The City of Ottawa l In kind contributions from: l Transport Canada l Environment Canada l Ontario Ministry of the Environment (MOE) l Ministère du Développement durable, de l'Environnement et des Parcs (of the province of Quebec) and l Health Canada l A-MAPS Environmental was contracted for this project
69 Contact information: l Natividad Urquizo 613-580-2424 x 27914 Natividad.Urquizo@ottawa.ca