1. GEOS-CHEM meeting: Effects of enhanced boreal forest fires on global CO Fok-Yan Leung with help and thanks to Jennifer Logan, Ed Hyer, Eric Kasischke, David Streets, Leonid Yurganov and Rose Yevich. Harvard University 5 April 2005.

2. Model version used in studies v5.05.03 for 1998 GEOS3 meteorology v7.02.02 for 2002 GEOS4 meteorology Difference in mean global OH between the versions for 2001 simulation is ~10.55 x 10 5 molecules/cm 3 in v7.02.02 vs. ~10.15 x 10 5 molecules/cm 3 in v5.05.03 Default GEOS-CHEM setting is to have all BIOBSRCE emissions distributed in the boundary layer

3. Important Issues involving boreal forest burning Consideration of ground fuel burning and fire regimes to emissions estimates Sensitivity of model results to injection heights of boreal forest biomass burning emissions. Flaws in either emissions estimates or parameterization of model or both – case studies of 1998 vs 2002.

4. 1998 emissions, Russia

5. Comparison of GEOS-CHEM results with CMDL surface site data- 1998 results

6. Comparison of GEOS-CHEM results with ground based column data – 1998 Results

7. Comparison of GEOS-CHEM results with CMDL surface site data; the effect of injection heights

8. Comparison of GEOS-CHEM results with ground based column data; the effect of injection heights

9. Comparison of drymassburned between 1998 and 2002 (KAS98 and KAS02)

10. Comparison between 1998 and 2002; model and CMDL surface data

11. Comparison between 1998 and 2002; column data

12. Differences between emission sets that make a difference Treatment of vegetation types (i.e. vegetation maps) –Forest vs. peatland burning (implications for injection heights) Assumptions about carbon loading, both above ground and below ground fuels –Also, what is the latitudinal dependence of fuel loading? Assumptions about fire regimes – seasonal variations –crown fires vs surface fires, and the fraction of fuel burned –Depth of below ground fuels burned –What is the relationship between burning and hotspots? Emission factors – a function of both fire regime and vegetation type Areas burned and how important are the geographical locations of the Siberian fires?

13. Are the problems actually in the emissions set? Or are there issues in the model that also need to be considered?

14. Appendices

15. 1998 and 2002 – high fire years (from Kasischke et al., 2004)

16. Assumptions about fires KAS98 and KAS02 (Kasischke et al., 2004)

17. Comparison of GEOS-CHEM results with CMDL surface site data; anomaly 1998 results

18. Comparison of GEOS-CHEM results with ground based column data; anomaly - 1998 results

19. Comparison of GEOS-CHEM results with CMDL surface site data; the effect of injection heights Anomaly

20. Comparison of GEOS-CHEM results with ground based column data; the effect of injection heights Anomaly