Type: Presentation
Venue: AGU Fall Meeting 2012
Citation:
John Worden; Kevin Wecht; Christian Frankenberg; Matthew J. Alvarado; Peter M. Bergamaschi; Kevin W. Bowman; Eric A. Kort; Susan S. Kulawik; Meemong Lee; Vivienne Payne; Helen M. Worden (2012) Top-down and bottom up estimates of methane emissions from the 2006 Indonesian peat fires using Aura TES satellite observations of CH4 and CO and GEOS-Chem." AGU Fall Meeting, San Francisco, CA.
Tropical fires represent a significant source of methane, yet their contribution to the global methane budget is highly uncertain because fire emissions are highly variable from year-to-year and because the CH4 emissions depend on the stage of the fire. In this paper we use new observations of atmospheric CH4 (as well as CO) in the free troposphere from the Aura Tropospheric Emission Sounder satellite instrument to place constraints on the role of fire emissions versus microbial production (e.g. wetlands and livestock) on the tropical atmospheric methane distribution during a time of significant peat fire emissions from Indonesia in the fall of 2006. We first evaluate the global CH4 distributions from TES and GEOS-Chem and find that biases between observation and model are consistent with previous validation studies of TES data using aircraft measurements. Comparisons account for the vertical resolution and a priori constraints associated with the TES CH4 and CO estimates. Tropospheric averages of CH4 and CO are calculated and the slopes of these distributions are compared to similar distributions calculated by the GEOS-Chem model. For the Indonesia peat fires, we find that TES and GEOS-Chem CH4 distributions as well as the slopes of the observed and modeled CH4/CO distributions are consistent (within the TES observation error). These comparisons provide confidence in the total CH4 emissions used in GEOS-Chem from Indonesia of 4 Tg with 2.8 Tg coming from the peat fires.