Comparison of Peroxy Radical Concentrations at Several Contrasting Sites

Abstract

The importance of the peroxy radicals in gas phase atmospheric chemistry has prompted the development of a number of methods for their measurement. These have resulted in several reports of H02 and R02 levels around the globe. The chemical amplifier has been used for measurements in seven intensive measurement campaigns over the last few years. The measured levels tell a great deal about the tropospheric chemistry of these radicals and also tell much about our understanding of the processes that create and destroy them. The results of these measured levels at sites that differ greatly in oxidant precursor concentration as well as photochemical activity are compared. A steady-state model has been developed to help explain the radical observations, and its use is discussed.