Organic compounds are emitted into the atmosphere from a variety of sources, both natural and man-made. The lifetimes of these compounds are governed by their reactions with the OH (hydroxyl) radical. After attack by OH (or other oxidants such as ozone, NO₃ radicals or Cl atoms) the organics undergo a series of transformations involving peroxy radicals and alkoxy radicals. The final product distributions are governed by the relative branching channels of these radical reactions.

At NCAR we study the reactions of organic compounds using two laboratory techniques. In the first, we use Fourier Transform Infrared Spectrometry to investigate the overall product yields. The second involves time-resolved IR laser spectroscopy to detect HO₂ (hydroperoxy) radicals directly. Coupled together, the two techniques offer a powerful means to study atmospheric oxidation mechanisms.

In this talk I will review some general principles of atmospheric oxidation chemistry, and highlight them with details of a few representative organic species.

Short Bio

Dr. Tyndall received BA with Honors in natural sciences Churchill College received in Cambridge England and a PhD 1982, at the Department of Physical Chemistry, Cambridge University, England. He has been engaged in laboratory studies of atmospheric oxidation mechanisms, published 100 total refereed publications in atmospheric chemistry and is a co-author of two books on atmospheric chemistry. He is currently, an editor of Geophysical Research Letters. Before joining NCAR as a scientist, Atmospheric Chemistry Division (Senior Scientist since 2002) he did a postdoctoral research at Max-Planck Institut für Chemie, Airchemistry Division, Mainz, Germany and Research Associate, CIRES, University of Colorado, Boulder, working in NOAA Aeronomy Laboratory.