PM 2.5 Transport From Wildfires

1. PM2.5 Transport From Wildfires Sean Ryan Case Study: Bugaboo Fire – Georgia/Florida, May 2007

2. Bugaboo Scrub Fire - Background • April to June 2007 • Largest fire in Georgia/Florida history Image courtesy U.S. Government

3. Bugaboo Scrub Fire - Background

4. Bugaboo Scrub Fire - Background • Started April 16, 2007 when high winds blew a tree onto power lines. • April 30th 80K acres burned • May 9th 116K acres burned • May 22nd 475K acres burned • Fire containment began in early June after heavy rainfall from tropical storm Barry.

5. Bugaboo Scrub Fire - Background • Smoke from the fire traveled hundreds of miles, affecting areas as far away as north Georgia and even Mississippi. • Atlanta • Visibility reduced to ¼ mile • Irritated eyes, noses, lungs, asthma

6. Purpose of This Study • Use MODIS aerosol optical thickness and HYSPLIT model back trajectories to track smoke from the fire on a regional scale. • Determine meteorological conditions that support the transport of smoke (PM2.5) long distances.

7. Methods • Wang & Christopher (2003) found that MODIS retrieved AOT correlated well (R=0.98) with 24-hr average PM2.5 measurements. • PM2.5 = (AOT + 0.012)/0.014 • Determine worst days (when out of compliance with EPA regulation) for Atlanta region and the near-fire region. • Determine synoptic scale meteorological conditions favorable to transport of smoke, or containment of smoke near the fires.

8. Methods • Used NCEP Reanalysis data to compute mean composite and anomaly analyses for days in each “regime.” • Used HYSPLIT model to compute trajectories

9. MODIS • Moderate Resolution Imaging Spectroradiometer • MODIS sensors on Terra and Aqua polar orbiting satellites • Products • Aerosol product  monitors ambient aerosol thickness, derives aerosol size distribution (ocean) and aerosol type (continents) • True Color

10. MODIS – Aerosol Retrieval Method

11. MODIS True Color Images 16 May, 2007 22 May, 2007

12. MODIS AOT Images 16 May, 2007 22 May, 2007

13. PM2.5 (MODIS Derived)

14. PM2.5 (MODIS Derived)

15. Meteorological Conditions - High ATL PM2.5

16. Meteorological Conditions - High ATL PM2.5

17. Meteorological Conditions - High ATL PM2.5

18. Meteorological Conditions - High ATL PM2.5

19. Atlanta skyline on 22 May, 2007 (image courtesy of AP)

20. Meteorological Conditions - High Fire Region PM2.5

21. Meteorological Conditions - High Fire Region PM2.5

22. Meteorological Conditions - High Fire Region PM2.5

23. Meteorological Conditions - High Fire Region PM2.5

24. Conclusions • High ATL PM2.5 Days • Anomalous ridging at the surface and mid-levels extending along east coast and into eastern Canada. • HYSPLIT trajectories confirm that source region for air over ATL on these days was almost directly over fire. • Smoke confined to fire region • Anomalous ridging across western and central U.S., with weak trough in place across eastern U.S. • HYSPLIT trajectories show that air on these days was confined relatively closely to the fires.

25. Resources • Wang, J., S.A. Christopher, 2004: Intercomparison between satellite-derived aerosol optical thickness and PM2.5 mass: Implications for air quality studies. Geophys. Res. Let., 30, ASC4. • Algorithm for Remote Sensing of Tropospheric Aerosol from MODIS. Algorithm Theoretical Basis Document, NASA Goddard Space Flight Center • Analyses and visualizations used in this study were produced with the Giovanni online data system, developed and maintained by the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC). • NCEP/NCAR Reanalyis Data, NOAA Climate Diagnostic Center, Climate Analysis Branch • HYSPLIT Model, NOAA Air Resources Laboratory