Venue: AGU Fall Meeting 2012
Kelley C. Wells; Dylan B. Millet; Karen E. Cady-Pereira; Mark W. Shephard; Ming Luo; Daven K. Henze (2012) Quantifying surface emissions of methanol using observations from the Tropospheric Emission Spectrometer. AGU Fall Meeting, San Francisco, CA
Methanol is the most abundant non-methane organic compound in the atmosphere, and a precursor of carbon monoxide, formaldehyde and ozone. Biogenic emissions from terrestrial plants constitute the largest fraction of the global methanol source, while biomass burning and anthropogenic emissions can make significant contributions on a regional scale. The recent availability of tropospheric methanol observations from space provides a powerful new constraint for understanding methanol emission processes on a global scale. Here we employ two years of global methanol observations from the Tropospheric Emission Spectrometer (TES) with the adjoint of the GEOS-Chem CTM to quantify the surface methanol flux, and interpret the results in terms of emission rates from different plant functional types. The satellite data imply a downward revision of the model emissions in portions of the tropics, and an upward revision in midlatitudes. The largest increases to the model emissions occur in areas that are dominated by shrubs and grasses, suggesting a refinement in methanol emission factors as a function of plant functional type. Applying the optimized emission rates in the model results in an improvement of the simulation as compared to an ensemble of airborne and ground-based observations.