Professor Education Education: B.S. (1995) Chemistry, California Institute of Technology Ph.D. (2000) Chemistry, Massachusetts Institute of Technology Research Research Areas: Analytical Chemistry Physical Chemistry Environmental/Atmospheric Chemistry Research Interests: 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 Selected Publications: 2018 2017 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. ; 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. 2014 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. Wiegand, J. R. ; L. Mathews, D. ; Smith, G. D. A UV–Vis Photoacoustic Spectrophotometer. Analytical Chemistry 2014, 86, 6049 - 6056. Phillips, S. M. ; Smith, G. D. Light Absorption by Charge Transfer Complexes in Brown Carbon Aerosols. Environmental Science & Technology Letters 2014, 1, 382 - 386. 2013 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. 2012 Renbaum-Wolff, L. ; Smith, G. D. "Virtual Injector" Flow Tube Method for Measuring Relative Rates Kinetics of Gas-Phase and Aerosol Species. Journal of Physical Chemistry A 2012, 116, 6664–6674. 2011 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. 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. 2009 Renbaum, L. ; Smith, G. The importance of phase in the radical-initiated oxidation of model organic aerosols: reactions of solid and liquid brassidic acid particles. Physical Chemistry Chemical Physics 2009, 11, 2441–2451. 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. 2007 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. 2006 Hearn, J. ; Smith, G. A mixed-phase relative rates technique for measuring aerosol reaction kinetics. Geophysical Research Letters 2006, 33, L17805, doi:10.1029/2006GL026963. Hearn, J. D. ; Smith, G. D. Reactions and mass spectra of complex particles using Aerosol CIMS. International Journal of Mass Spectrometry 2006, 258, 95–103. 2005 Hearn, J. ; Smith, G. Measuring rates of reaction in supercooled organic particles with implications for atmospheric aerosol. Physical Chemistry Chemical Physics 2005, 7, 2549–2551. Hearn, J. ; Lovett, A. ; Smith, G. Ozonolysis of oleic acid particles: evidence for a surface reaction and secondary reactions involving Criegee intermediates. Physical Chemistry Chemical Physics 2005, 7, 501–511. 2004 Hearn, J. ; Smith, G. Kinetics and product studies for ozonolysis reactions of organic particles using aerosol CIMS. Journal of Physical Chemistry A 2004, 108, 10019–10029. Hearn, J. ; Smith, G. ; Smith, G. A Chemical Ionization Mass Spectrometry Method for the Online Analysis of Organic Aerosols. Analytical Chemistry 2004, 76, 2820–2826. 2003 Smith, G. D. ; Woods, E. ; Baer, T. ; Miller, R. E. Aerosol uptake described by numerical solution of the diffusion - Reaction equations in the particle. Journal of Physical Chemistry A 2003, 107, 9582–9587. 2002 Smith, G. D. ; Molina, L. T. ; Molina, M. J. Measurement of radical quantum yields from formaldehyde photolysis between 269 and 339 nm. Journal of Physical Chemistry A 2002, 106, 1233–1240. Woods, E. ; Smith, G. ; Miller, R. ; Baer, T. ; Baer, T. ; Miller, R. Depth Profiling of Heterogeneously Mixed Aerosol Particles Using Single-Particle Mass Spectrometry. Analytical Chemistry 2002, 74, 1642–1649. Smith, G. ; Woods, E. ; DeForest, C. ; Baer, T. ; Miller, R. ; Baer, T. ; Miller, R. Reactive Uptake of Ozone by Oleic Acid Aerosol Particles: Application of Single-Particle Mass Spectrometry to Heterogeneous Reaction Kinetics. Journal of Physical Chemistry A 2002, 106, 8085–8095. Sykes, D. ; Woods, E. ; Smith, G. ; Baer, T. ; Miller, R. ; Baer, T. ; Miller, R. Thermal vaporization-vacuum ultraviolet laser ionization time-of-flight mass spectrometry of single aerosol particles. Analytical Chemistry 2002, 74, 2048–2052. 2001 Woods, E. ; Smith, G. D. ; Dessiaterik, Y. ; Baer, T. ; Miller, R. E. Quantitative detection of aromatic compounds in single aerosol particle mass spectrometry. Analytical Chemistry 2001, 73, 2317–2322. Smith, G. ; Tablas, F. ; Molina, L. ; Molina, M. ; Molina, M. Measurement of Relative Product Yields from the Photolysis of Dichlorine Monoxide (Cl2O). Journal of Physical Chemistry A 2001, 105, 8658–8664. 2000 Smith, G. ; Molina, L. ; Molina, M. ; Molina, M. Temperature dependence of O(1D) quantum yields from the photolysis of ozone between 295 and 338 nm. Journal of Physical Chemistry A 2000, 104, 8916–8921. 1997 Percival, C. J. ; Smith, G. ; Molina, L. ; Molina, M. ; Molina, M. Temperature and Pressure Dependence of the Rate Constant for the ClO + NO2 Reaction. Journal of Physical Chemistry A 1997, 101, 8830–8833. 1995 Smith, G. D. ; Bernstein, K. E. {BULLET: a computer simulation of shotgun DNA sequencing}. Bioinformatics 1995, 11, 155–157.