Spectroscopy and Photochemistry of Atmospheric Organic Hydrates Relevant in Aerosol Nucleation and Climate

I’m researching atmospheric organic hydrates in order to understand their role in aerosol nucleation and effects on climate.  Organics comprise a significant portion of aerosols.  The organics I’m interested in are gem-diols and their fluorinated analogs as well as organic acids. In this research we seek to understand how organics are processed by solar radiation in the atmosphere and what spectral changes occur as they bind to water.  This will be achieved through spectroscopy (Fourier Transform and Cavity Ring Down) to reveal shifts in spectra and subsequently the ability of aerosols to scatter and absorb light as well as their effects on temperature, radiative transfer and climate.

The reactions we propose to study are initiated by light in the solar wavelength range that is abundant at the Earth’s surface, the low energy visible red. Thermodynamic data will be obtained in order to evaluate the abundance of compounds and the energy required to initiate a reaction that processes these organics in an aqueous environment. By studying anthropogenic as well as biogenic organic acids and alcohols, we can understand the atmospheric fate and processingof these organics and predict their role in the broader scope of climate change through comparing the natural and human-made sources.

Publications:

1. "Experimental and Theoretical Study of the OH Vibrational Spectra and Overtone Chemistry of Gas-Phase Vinylacetic Acid." M. E. Dunn, G. C. Shields, K. Takahashi, R. T. Skodje and V. Vaida Journal of Physical Chemistry A, 112(41), 10226-10235 (2008).

Insturments:

Cavity Ring Down, CRD

Bruker FT-IR Spectrometer