Summary: Constraining global isoprene emissions with Global Ozone Monitoring
Experiment (GOME) formaldehyde column measurements
Changsub Shim, Yuhang Wang, and Yunsoo Choi
Department of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
Paul I. Palmer and Dorian S. Abbot
Department of Earth and Planetary Sciences and Division of Engineering and Applied Sciences, Harvard University,
Cambridge, Massachusetts, USA
Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
Received 24 November 2004; revised 21 July 2005; accepted 15 September 2005; published 17 December 2005.
 Biogenic isoprene plays an important role in tropospheric chemistry. Current isoprene
emission estimates are highly uncertain because of a lack of direct observations.
Formaldehyde (HCHO) is a high-yield product of isoprene oxidation. The short
photochemical lifetime of HCHO allows the observation of this trace gas to help constrain
isoprene emissions. We use HCHO column observations from the Global
Ozone Monitoring Experiment (GOME). These global data are particularly useful for
studying large isoprene emissions from the tropics, where in situ observations are sparse.
Using the global Goddard Earth Observing SystemChemistry (GEOS-CHEM)
chemical transport model as the forward model, a Bayesian inversion of GOME HCHO
observations from September 1996 to August 1997 is conducted to calculate global