This project involves investigation of selected oxygenated and nitrogen-containing organic compounds through laboratory and theoretical photochemical studies, and atmospheric observations. The studies will involve (1) laboratory quantification of photolysis quantum yields of peroxyacetyl nitrate, and hydroxylmethyl hydroperoxide in the near-infrared spectral region along with ab initio calculations of the strengths of the overtone transitions of these species as well as peroxynitrous acid (HOONO), (2) laboratory measurement of absorption cross sections and photolysis quantum yields for a number of aldehydes in the ultraviolet spectral region, (3) measurement of atmospheric peroxy nitrous acid (HOONO) and acetaldehyde using ground-based solar spectra along with laboratory measurement of infrared spectra of these species, (4) measurements of the isotopic fractionation of molecular hydrogen formed in the solar photolysis of formaldehyde, and (5) experiments to quantify the hydroxyl radical product yield from the reaction of molecular oxygen with vinoxy radicals. Together, these studies will improve understanding of the atmospheric fate of organic oxygenated and nitrogen-containing species, and will lead to enhanced capability to predict their impact on free radical, ozone and aerosol abundances.
The broader impacts of this project include improving our understanding of atmospheric processes related to ozone and aerosol formation, and thus leading to better strategies for improvement of air quality. This research will also provide education and training for graduate and undergraduate students, and will be enhanced by its collaborative nature involving chemists, geochemists and physicists.
