SUNY scientists examine the chemical reactions that give rise to excessive atmospheric ozone.

Scientists know that organic compounds and nitrogen oxides interact with sunlight to produce ozone that pollutes the air we breath. Although a scientist may know that a particular type of ozone-producing compound is emitted, it can be very difficult to predict which specific reactions the molecules of the compound will undergo. A molecule's fate is constantly changing as it reacts with other nearby molecules or falls apart to make two new molecules. The determination of the amount of ozone production from any one molecule is largely a mystery.

Computational modeling provides a method of discovering the most likely fates of atmospheric molecules. Models take into account emissions of organic compounds and nitrogen oxides, their transport, and their chemical reactions. Scientists can use the computational models to test regulations and requirements for minimizing ozone concentrations. If the models do not consider the correct chemical fates of the organic compounds, then the regulations may not be effective, or they may be more costly than necessary.

Critical factors in atmospheric molecules' destinies are the reactions of alkoxy radicals, molecules that have an unpaired electron on an oxygen atom bound directly to a carbon atom. They are important because they are formed from nearly every organic compound in the atmosphere. At any given time, they might undergo any of five different reactions, which determine the amount of ozone produced.

Access Online | Posted 7-16-2002