Thornton Group Department of Atmospheric Sciences University of Washington, Seattle
Group Members	Research Projects	Joel Thornton
		thornton@atmos.washington.edu

Our research projects are generally geared toward improving our understanding of regional and global tropospheric oxidation chemistry, and its relation to air quality and climate, through a combination of field measurements, laboratory process studies, and computer modeling. In particular, we are interested in both the daytime and nighttime chemistry of nitrogen oxide radicals, which act as catalysts for ozone production, controls on the OH radical, and as a source of nitrogen to ecosystems. Nocturnal nitrogen oxide chemistry, via NO3 and N2O5, involves heterogeneous reactions on aerosols and reactions with biogenic volatile organic compounds with implications for aerosol mass (and therefore climate forcings) and halogen chemistry in the polluted marine boundary layer. We are thus also interested in the effects of oxidants as sources and sinks of aerosol organic mass, and the role of heterogeneous chemistry generally, but specifically that involved in the removal of nitrogen oxides, and the activation and recycling of halogen species. As part of these efforts we focus on the development of field deployable detection technologies involving selected-negative ion chemical ionization mass spectrometry and unique kinetic and product studies of heterogeneous chemistry in the laboratory. Below are links to more detailed descriptions of recent results and activities related to these topics.

A version of the UW-CIMS instrument in field-deployable form. New York City skyline from the RV Knorr. Photo by Chris Cappa

Nitrogen Oxide Chemistry, Transport, and Deposition	Chemistry and Effects of Aerosol Organic Matter	Tropospheric Halogen Chemistry
Influence of Asian pollution at Mount Bachelor during INTEX-B 2006	Organics at the Gas-Aerosol Interface	Laboratory Studies of Halogen Activation from Sea Ice Brines
Acyl Peroxy Nitrate Fluxes and Vertical Gradients over a Ponderosa Pine Forest During BEARPEX 2007	Heterogeneous Oxidation of Aerosol Organic Matter	ClNO2 Production by N2O5 During LILACS and ICEALOT
N2O5 and NO3 Reactivity Determinations	Gas-Particle Composition Measurements by Impaction-CIMS
TO BE UPDATED SOON		TO BE UPDATED SOON