1. Uncertainties in Wildfire Emission Estimates Workshop on Regional Emissions & Air Quality Modeling July 30, 2008 Shawn Urbanski, Wei Min Hao, Bryce Nordgren Missoula Fire Sciences Laboratory, US Forest Service

2. Wildfire Fire Emission Inventories The Fire Sciences Laboratory has developed a MODIS- DB burned area algorithm to: Develop wildfire emission inventories for the western US Provide ‘rapid response’ wildfire emissions for air quality forecasting/management activities Demonstrate a prototype smoke dispersion – air quality forecasting system (assimilation of MODIS derived emissions for predicting fire impacts on regional air quality)

3. Emission Estimate Method Fuel Loading Fire Information Meteorology Consumption Model Emission Factors Fuel Loading Land cover / fuel map Fuel loading model (vegetation load by fuel class) Meteorology – analysis / observations Fuel moisture (NFDRS) Consumption Model First Order Fire Effects Model (FOFEM) Fire Information MODIS-DB system (Missoula, MT) 4 daily observation per location Complete coverage of western US Combines active fire and burn scar detections – daily burned area at 1-km 2

4. X = A * M *F C * EF X Mass emission of X over Δt : M (mass of fuel - dry vegetation) A ( area burned ) Fc ( fraction of fuel consumed ) EF ( emission factor X kg / kg fuel consumed) detection & area spatial & temporal distribution land cover map fuel loading model fuel consumption model meteorology fuel condition (moisture) fire average or phase specific cover type

5. Uncertainties Associated with Land Cover and Fuel Loading Land Cover Fuel Characteristic Classifications System (FCCS) CONUS 1-km resolution 112 cover types USFS PNW Research Station, McKenzie (2007) FIA Forest Map CONUS 250-m resolution 138 SAF forest types Non-forested areas use FCCS USFS Forest Inventory & Analysis program and Remote Sensing Applications Center Fuel Loading Fuel Characteristic Classifications System (FCCS) FCCS fuel loading model Cross-walk to SAF forest types FOFEM Reference Database SAF/SRM cover types Cross-walk to FCCS USFS RMRS Missoula Fire Sciences Laboratory

6. Uncertainties Associated with Land Cover and Fuel Loading CaseLand cover map Fuel loading AFCCSFOFEM BFCCS CFIAFOFEM DFIAFCCS Fuel loading uncertainty – Case A vs. Case B Map uncertainty – Case C vs. Case D

7. Jan-06Jul-06Oct-06Apr-06Jan-07Jul-07Oct-07Apr-07 Monthly Burned Area Western US Burned area (km 2 ) 2000 6000 10000 0

8. Jan-06Jul-06Oct-06Apr-06Jan-07Jul-07Oct-07Apr-07 Monthly CO Emissions Western US 1000 3000 5000 0 CO emissions (Gigagrams -CO)

9. 0 2000 10000 20062007 Annual CO Emissions by Fuel Method 6000 B A CDB A CD FUEL METHOD CO emissions (Gigagram) range ~20%range ~10% range in fuel consumption ~10% ~20%

10. 0 500 1500 20062007 Annual PM2.5 Emissions by Fuel Method 1000 B A CDB A CD FUEL METHOD PM 2.5 emissions (Gigagram) range ~20%range ~10%

11. 0 100 300 20062007 Annual NO X Emissions by Fuel Method 200 400 B A CDB A CD FUEL METHOD NO X emissions (Gigagram) range ~20%range ~5%

12. 0 50 250 20062007 Annual Methanol Emissions by Fuel Method 150 100 200 B A CDB A CD FUEL METHOD methanol emissions (Gigagram) range ~20%range ~10% NMVOC ~1-2% of C OVOC 60-70% of NMVOC

13. 0 300 20062007 Annual Formaldehyde Emissions by Fuel Method 100 200 B A CDB A CD FUEL METHOD formaldehyde emissions (Gigagram) range ~20%range ~10%

14. 2006 E_CO Metric ton-CO km -2 -270.0 - -168.0 -168.0 - -86.0 -86.0 - -34.0 -34.0 - -7.0 -7.0 - 11.0 11.0 - 52.0 52.0 - 157.0 157.0 - 400.0 400.0 - 850.0 Fuel Loading Impact on CO emissions Min = -266 Metric ton km -2 Max = +826 Metric ton km -2

15. 24.0 - 60.4 2006 E_PM2.5 Metric ton – PM2.5 km -2 -40.5 - -27.0 -26.9 - -13.1 -13.0 - -5.2 -5.1 - -1.1 -1.0 - 1.6 1.7 - 7.8 7.9 - 23.9 60.5 - 125.3 Fuel Loading Impact on PM2.5 emissions Min = - 41 Metric ton km -2 Max = +125 Metric ton km -2

16. -0.1 - 0.6 2006 E_NO X Metric ton – NO X km - 2 -14.8 - -8.5 -8.4 - -3.5 -3.4 - -1.1 -1.0 - -0.2 0.7 - 2.3 2.4 - 5.6 5.7 - 11.4 11.5 - 23.7 Fuel Loading Impact on NO x emissions Min = - 15 Metric ton km -2 Max = +24 Metric ton km -2

17. 2007 E_CO Metric ton CO km -2 -545.6 - -332.1 -332.0 - -194.8 -194.7 - -99.0 -98.9 - -41.1 -41.0 - -9.2 -9.1 - 21.8 21.9 - 108.3 108.4 - 324.6 324.7 - 787.8 Land Cover Map Impact on CO emissions Min = - 546 Metric ton km -2 Max = +787 Metric ton km -2

18. 2007 E_PM2.5 Metric ton PM2.5 km -2 -82.8 - -50.4 -50.3 - -29.5 -29.4 - -15.0 -14.9 - -6.2 -6.1 - -1.4 -1.3 - 3.3 3.4 - 16.4 16.5 - 49.2 49.3 - 119.5 Land Cover Map Impact on PM 2.5 emissions Min = -83 Metric ton km -2 Max = +120 Metric ton km -2

19. 2007 E_NO X Metric ton NO X km -2 -15.6 - -9.3 -9.2 - -5.4 -5.3 - -2.9 -2.8 - -1.2 -1.1 - -0.3 -0.2 - 0.6 0.7 - 3.0 3.1 - 9.3 9.4 - 22.6 Land Cover Map Impact on NO x emissions Min = -16 Metric ton km -2 Max = +23 Metric ton km -2

20. Summary Choice of land cover map and fuel model have significant impact on emission estimate Uncertainty in annual emissions for western US: 20% map and fuel model combined 10% map or fuel model alone Uncertainty varies spatially and temporally Large regional uncertainties e.g. 30% in MT and ID due to map choice alone, ~ 60% map and fuel model combined Don’t forget burned area, consumption model, & EF’s