Carbon isotopic signatures of methanol and acetaldehyde emitted from biomass burning source

Abstract

We present carbon isotopic signatures of methanol and acetaldehyde emitted from biomass burning sources using laboratory experiments. The respective SC of methanol and acetaldehyde emitted from burning experiments of five plant materials (three C 3 and two C 4 plants) were -20-46‰ and -11-25‰ The variation in δ 13 C of methanol depends on the δ 13 C of the fuel biomass and burning conditions, but the variation in δ 13 C of acetaldehyde depends on the δ 13 C of fuel biomass and is independent of burning conditions. Combining these observations with previously reported global distributions of fire types, burning conditions, amounts of biomass burned, vegetation types, and emission factors, we estimated the global isotopic signature for biomass burning source as -33 ± 16‰ for methanol. Copyright 2009 by the American Geophysical Union.