HR: 10:35h
AN: A32B-02 INVITED     [Abstracts]
TI: Emissions From Boreal fires: Issues in Reconciling Bottom-up and Top-down Estimates.
AU: * Logan, J A
EM: jal@io.harvard.edu
AF: Harvard University, DEAS/DEPS, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Leung, F
EM: fyl@io.harvard.edu
AF: Harvard University, DEAS/DEPS, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138 United States
AB: Boreal fires have produced hemispheric-scale pollution in recent high-fire years such as 1998, 2002, and 2003. Emissions from these fires caused significant interannual variability in CO and aerosols at northern mid-latitudes. We used the GEOS-Chem model to constrain estimates of emissions from the boreal fires in 1998, and to investigate effects on atmospheric composition. Our results for simulated CO were strongly influenced by assumptions made about the heights at which the fire emissions were injected in the model. We found that it was possible to simulate the anomaly in both surface and column CO only if a significant fraction of the emissions were injected above the boundary layer. Surface data alone did not provide an adequate constraint on the fire emissions/injection heights. Literature estimates for CO emissions from boreal fires in 1998 and 2002 are similar, but preliminary GEOS-Chem simulations, together with CO observations, imply that emissions in 2002 must have been smaller than those in 1998. We will discuss the implications of the top-down inferences for constraining uncertainties in the bottom-up estimates, particularly in terms of assumptions about surface fuel consumption.
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005