- Chem Sci 402D
Assistant Professor, Chemistry
- PhD, University of Nevada, Reno
Atmospheric aerosols and clouds play important roles in determining the Earth’s climate. Trace gases and aerosols, constitute only a tiny fraction of the atmospheric mass, however they interfere with the solar radiative transfer through the atmosphere. Along with molecular scattering and absorption from gases, aerosol particles and clouds determine in part what fraction of solar radiation reaches the Earth’s surface and what fraction of it returns to space. Aerosol particles are especially complex. Particles can exert both a direct effect by reflecting and absorbing solar radiation. They also promote an indirect effect by influencing cloud properties and lifetimes. Water uptake by particles is responsible for haze formation, cloud formation, and can affect the amount of water vapor in the atmosphere, thus it is a key indirect effect. Overall, the uncertainty in aerosol radiative forcing is considerably larger than that due to greenhouse gases (IPCC 1996, 2007). This limits our scientific ability to predict future surface temperature changes and to unambiguously detect a greenhouse warming signal. Organic aerosol components arise from a combination of anthropogenic and biogenic sources. These include but are not limited to: biomass combustion, vehicle emissions, meat cooking, secondary reactions, and emissions from plants and animals. The components of aerosol may either by emitted to the atmosphere as fine particulate matter or as gases.
My primary research interests are to identify organic aerosol constituents from a variety of atmospheric environments. For identification of we use advanced liquid chromatography (LC) separations and advanced mass spectrometry (MS) techniques. Hydrophilic organic compounds are some of the toughest organic compounds to separate by traditional LC techniques. We are currently exploring new LC column chemistries with ultra-high pressure pumps for fast and thorough separations. We exploit the identity of organic compounds by using several MS techniques as well.
Links of Interest
- Understanding the identities, occurrence, and transformation of aerosol organic compounds
- Identifying organic aerosol constituents from a variety of atmospheric environments
- Exploration of new LC column chemistries with ultrahigh pressure pumps for fast and thorough separations
- Aqueous reaction pathways