Physics/Environmental Chemistry Seminars


Marsha I. Lester  
Edmund J. and Louise W. Kahn Professor in the Natural Sciences
Department of Chemistry, University of Pennsylvania


Physics Seminar at Mercer University
Thursday 10/21/2004, 3:45pm
Willet Science Center 101

Infrared Spectroscopy and Dynamics of
Reaction Intermediates in Atmospheric Chemistry

Free Public Lecture at Wesleyan College
Thursday 10/21/2004, 7pm
Peyton Anderson Amphitheatre, Taylor Hall

Significant Radical Chemistry
in the Lower Atmosphere

Free radicals, in particular HOx and NOx radicals, play a prominent role in the chemistry of the lower atmosphere.  For example, hydroxyl radicals (OH) are often known as the troposphere’s “detergent” because they break down most trace constituents of the atmosphere.  More generally, these radicals are involved in the oxidation of volatile organic compounds, the formation of photochemical smog, the production of acid rain, and the catalytic destruction of ozone in the stratosphere.  This lecture will cover key chemical reactions associated with the very complex chemistry of the lower atmosphere, and touch on current policy-related work with regard to air pollution regulation and abatement.  In addition, the presentation will focus on a new view of the mechanism for one of the most important reactions in the lower atmosphere, the conversion of OH and NO2 radicals into stable nitric acid (HNO3), which is expected to have a profound impact on atmospheric models of HOx and NOx chemistry.

Please join us for light refreshments at 3:30pm outside WSC 109.