Tropospheric methanol observations from space: constraints on the seasonality of biogenetic emissions

Author: K.C. Wells, Karen Cady-Pereira and Yaping Xiao
Date: 
December 9, 2011
Type: 
Poster presentation
Venue: 
AGU Fall Meeting 2011
Citation: 

K.C. Wells, D.B. Millet, Karen E. Cady Pereira, M.W. Shephard, Yaping Xiao, C. Clerbaux (2011) Tropospheric methanol observations from space: constraints on the seasonality of biogenetic emissions. AGU Fall Meeting 2011.

Methanol is the most abundant non-methane organic compound in the atmosphere, and is an important precursor of atmospheric pollutants such as CO and formaldehyde. The recent development of methanol retrievals from nadir-viewing satellite-based platforms offers powerful new information for quantifying methanol emissions on a global scale. This study uses methanol observations from the Tropospheric Emission Spectrometer (TES) on the Aura satellite and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp-A satellite, in conjunction with aircraft data, to investigate methanol emissions from major plant functional types in the GEOS-Chem global chemical transport model (driven with MEGAN biogenic emissions). We first evaluate the TES methanol retrievals by comparing to simulation results and flight observations from several North American field campaigns. Results show that the retrieval performs well when the degrees of freedom for signal are above 0.5. We analyze one full year of TES and IASI observations and find a persistent model underestimate in springtime, and make recommendations for an improved seasonal distribution of biogenic methanol emissions over temperate regions of the globe.