Modeling Biogenic Emission Sources of Acetone and Other Oxygenated Organic Carbon Compounds

Acetone is of considerable interest in atmospheric chemistry as a source of HOx radicals and peroxyacetylnitrate (PAN) to the upper troposphere. The potential biogenic sources of acetone include terrestrial plant canopies, oxidation of dead plant matter, harvest of cultivated plants, biomass burning, and the oceans. These sources are very poorly constrained at present. Based on laboratory, field, and satellite observations to date, we present a first global modeling approach for estimating daily emissions of acetone from the terrestrial biosphere. Our modeling approach is driven by observed surface climate and estimates of vegetation leaf area index (LAI) generated at 0.5 degree spatial resolution from the NOAA satellite Advanced Very High Resolution Radiometer (AVHRR). Seasonal changes in LAI are estimated using modified MODIS radiative transfer algorithms to identify the probable dates and locations of crop harvest in cultivated areas and litterfall of newly dead plant matter in non-cultivated areas. Temperature-dependent emission factors are applied to derive global budgets of acetone fluxes from terrestrial plant canopies, oxidation of dead plant matter, and harvest of cultivated plants.