Current Research

The Smith group studies the chemistry and optical properties of aerosol particles that are important in the atmosphere.  In particular, we develop instrumentation to measure how they scatter and absorb UV-visible sunlight.

We develop and use a variety of tools such as:

 

* photoacoustic spectroscopy (PAS) to measure absorption by particles

 

* cavity ringdown (CRD) and broadband cavity-enhanced spectroscopy (BBCES) to measure extinction (scattering + absorption) by particles

 

*filter collection with offline analysis to learn about how and why ambient aerosols absorb sunlight 

Selected Publications

Phillips, S. M. ; Bellcross, A. D. ; Smith, G. D. Light Absorption by Brown Carbon in the Southeastern United States is pH-dependent. Environmental Science & Technology 2017, 51, 6782 - 6790.
Phillips, S. M. ; Smith, G. D. Spectroscopic comparison of water- and methanol-soluble brown carbon particulate matter. Aerosol Science and Technology 2017, 51, 1113 - 1121.
Phillips, S. M. ; Smith, G. D. Further Evidence for Charge Transfer Complexes in Brown Carbon Aerosols from Excitation–Emission Matrix Fluorescence Spectroscopy. The Journal of Physical Chemistry A 2014, 141205113635004.
Phillips, S. M. ; Smith, G. D. Light Absorption by Charge Transfer Complexes in Brown Carbon Aerosols. Environmental Science & Technology Letters 2014, 1, 382 - 386.
Wiegand, J. R. ; L. Mathews, D. ; Smith, G. D. A UV–Vis Photoacoustic Spectrophotometer. Analytical Chemistry 2014, 86, 6049 - 6056.
Toole, J. R. ; Renbaum-Wolff, L. ; Smith, G. D. A Calibration Technique for Improving Refractive Index Retrieval from Aerosol Cavity Ring-Down Spectroscopy. Aerosol Science And Technology 2013, 47, 955–965.
Zhao, Z. ; Husainy, S. ; Smith, G. D. Kinetics Studies of the Gas-Phase Reactions of NO 3 Radicals with Series of 1-Alkenes, Dienes, Cycloalkenes, Alkenols, and Alkenals. The Journal of Physical Chemistry A 2011, 115, 12161 - 12172.
Zhao, Z. ; Husainy, S. ; Stoudemayer, C. T. ; Smith, G. D. Reactive uptake of NO3 radicals by unsaturated fatty acid particles. Physical Chemistry Chemical Physics 2011, 13, 17809.
Renbaum, L. H. ; Smith, G. D. Artifacts in measuring aerosol uptake kinetics: the roles of time, concentration and adsorption. Atmospheric Chemistry and Physics Discussions 2011, 11, 7971 - 8002.
Renbaum, L. ; Smith, G. Organic nitrate formation in the radical-initiated oxidation of model aerosol particles in the presence of NOx. Physical Chemistry Chemical Physics 2009, 11, 8040–8047.
Hearn, J. ; Smith, G. Ozonolysis of mixed oleic acid/n-docosane particles: The roles of phase, morphology, and metastable states. Journal of Physical Chemistry A 2007, 111, 11059–11065.
Hearn, J. ; Renbaum, L. ; Wang, X. ; Smith, G. Kinetics and products from reaction of Cl radicals with dioctyl sebacate (DOS) particles in O2: a model for radical-initiated oxidation of organic aerosols. Physical Chemistry Chemical Physics 2007, 9, 4803–4813.