Seminar

Abstract

Photochemical oxidation of volatile organic compounds (VOCs) is central to the formation of tropospheric ozone and SOA. It has become clear that models of VOC oxidation are often inadequate, in particular away from urban centers. Formaldehyde and α-dicarbonyls are oxidation products of many important VOCs and thus can be used as tracers of VOC oxidation chemistry.

We have developed robust instrumentation for ultra-high sensitivity measurement of these VOC tracers by combining spectroscopic techniques that are new for field instrumentation with novel lasers. We will compare results from atmospheric models of VOC oxidation chemistry with measurements from rural sites and laboratory measurements of reaction kinetics. We will discuss implications for models of ozone formation and SOA formation from glyoxal. We will also present a study of the chemical processes controlling the fate of glyoxal in aerosol to gain insight into organic reaction mechanisms that could affect aerosol yields and optical properties.