Elevated Glyoxal Concentrations over the Eastern Equatorial Pacific: A Direct Biogenic Source?

Wednesday, 17 December 2014
Ruixiong Zhang, Georgia Institute of Technology Main Campus, Atlanta, GA, United States, Yuhang Wang, Georgia Inst of Technology, Atlanta, GA, United States and Christophe Lerot, Belgian Institute for Space Aeronomy, Brussels, Belgium
Elevated atmospheric glyoxal (CHOCHO) was observed over the eastern equatorial Pacific by satellite and ship measurements. We investigated the source contributions through inverse modeling using GOME-2 observations (2007-2012) and the GEOS-Chem model. The observed high glyoxal to HCHO column ratio over the region indicates the potential presence of a direct source of glyoxal rather than secondary production. A bimodal seasonal cycle of glyoxal concentrations was found, providing further evidence for a biogenic origin of glyoxal emission. The estimate of the primary glyoxal emission over the eastern equatorial Pacific is 20-40Tg/yr, which is comparable to the previous estimate of the global continential glyoxal emission.