US EPA 2007 National Air Quality Conferences February 12, 2007 Presented by Charles L. Blanchard

1. Forecasting Challenges: Impacts of Local Emissions on PM2.5 Mass Concentrations in Birmingham, Alabama US EPA 2007 National Air Quality Conferences February 12, 2007 Presented by Charles L. Blanchard Sponsored by Jefferson County Department of Health

2. Outline • PM2.5 AQI forecasting during 2005 • Local PM2.5 spikes • Local PM emissions • Factors influencing PM spikes • Implications for forecasting The theme: Local emissions affect forecasting success. What forecasting tools are needed?

4. JCDH PM2.5 Forecasting in 2005 Accuracy of AQI Category Forecasts (Good-Moderate-Sensitive-Unhealthy) Overall Jan – Dec 2005 = 72 Percent Monthly Ranges = 52 to 84 Percent

5. 24-hour moving averages Forecast 5-8-2005 AQI 60 Moderate Forecast correct except at N. Birmingham monitor

6. 1-hour concentrations Hourly data show spikes at Wylam and N. Birmingham

7. What are the PM2.5 spikes? • Local and urban PM contributions are superimposed on regional component • Multiple lines of evidence link local excess PM at Wylam and North Birmingham to several geographical source complexes

8. (Compared with 15 ug m -3 Annual PM2.5 NAAQS)

9. (Compared with 35 ug m-3, new 24-hr PM2.5 NAAQS, effective 12-18-2006)

10. PM 2.5 at Wylam and N. Birminghamcan be split into three components (annual average values) • Regional component ~12 – 14 mg m-3 • General urban component ~2 mg m-3 • Local component ~3 – 4 mg m-3

11. Regional PM Local PM Influences General Urban PM General Urban PM (Sites Ordered From SW to NE)

12. Factors Influencing PM Spikes • Local surface wind direction & speed • Local sources and intermittent emissions • Day of week (usually on weekdays) • Time of day

13. Factors Influencing PM Spikes: I. Local Surface Wind Direction

14. 0 0 0 0 315 315 45 45 315 315 45 45 270 270 90 90 270 270 90 90 0 0 2 2 4 4 6 6 8 8 0 0 1 1 2 2 3 3 4 4 OC ( OC ( ug ug m m - - 3) 3) EC ( ug ug m m - - 3) 3) 225 225 135 135 225 225 135 135 180 180 180 180 0 0 0 0 315 315 45 45 315 315 45 45 270 270 90 90 270 270 90 90 0 0 200 200 400 400 600 600 800 800 0 0 20 20 40 40 60 60 80 80 CO ( CO ( ppbv ppbv ) ) NOy NOy ( ( ppbv ppbv ) ) 225 225 135 135 225 225 135 135 180 180 180 180 Mean hourly concentrations by wind direction at N. Bhm, 2001-2004

15. PM2.5 (mg m-3)

16. PM10 Measurements

17. SO2 (ppbv)

18. Factors Influencing PM Spikes: II. Local PM Sources and Intermittent Emissions

19. Regional and Urban Carbon Both Contribute to PM2.5 Note: Calculated urban modern TC and OC are zero within limits of measurement uncertainties.

20. Birmingham Metals Concentrations Are High Compared to Other Cities Calcium not measured at Atlanta

21. Intermittent emissions - observed plume duration 10 min

22. Factors Influencing PM Spikes: III. Day of Week

23. Fine PM > 80 mg m-3

27. Factors Influencing PM Spikes: IV. Time of Day

28. Fine PM > 80 mg m-3

29. Proximity to PM Sources Affects Sites Many days with unique spikes at one urban site One regional PM episode

30. Implications for Forecasting: Are Multiple Approaches Needed to Incorporate PM Spikes? • Meteorological analysis (regional scale) • Modeling (local emission sources) • Empirical methods (transients)