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

We present carbon isotopic signatures of methanol and acetaldehyde emitted from biomass burning sources using laboratory experiments. The respective delta C-13 of methanol and acetaldehyde emitted from burning experiments of five plant materials ( three C-3 and two C-4 plants) were -20 - -46 parts per thousand and -11 - -25 parts per thousand. The variation in delta C-13 of methanol depends on the delta C-13 of the fuel biomass and burning conditions, but the variation in delta C-13 of acetaldehyde depends on the delta C-13 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 parts per thousand for methanol. Citation: Yamada, K., R. Hattori, Y. Ito, H. Shibata, and N. Yoshida (2009), Carbon isotopic signatures of methanol and acetaldehyde emitted from biomass burning source, Geophys. Res. Lett., 36, L18807, doi:10.1029/2009GL038962.