AVS 49th International Symposium
    Advancing Toward Sustainability Topical Conference Tuesday Sessions
       Session AT-TuM

Invited Paper AT-TuM3
Atmospheric Aerosol Detection, Analysis and Transformation

Tuesday, November 5, 2002, 9:00 am, Room C-210

Session: Aerosols and Climate Change, Growing Energy Demands, and Benign Semiconductor Manufacturing
Presenter: P.H. McMurry, University of Minnesota
Correspondent: Click to Email
Atmospheric aerosol particles scatter light, deposit on surfaces and in lungs, and participate in chemical transformations. This lecture will focus on the formation of new particles in the atmosphere by homogeneous nucleation, and on the chemical and physical properties of such freshly nucleated particles. It is important to understand nucleation since it affects the number concentrations of particles in the atmosphere. Number concentrations, in turn, determine the extent to which clouds form, and clouds play a central role in the earth's radiation balance. Our understanding of nucleation has progressed rapidly in the past few years due to recent advances in measurement. Routine measurements of aerosol size distributions down to 3 nm are now possible. Such measurements have shown that nucleation is ubiquitous in the atmosphere. We now are carrying out measurements that will help us understand what species are responsible for the formation and growth of new atmospheric particles. We have developed techniques to measure properties of freshly nucleated (3-10 nm) particles, including their tendency to absorb water, their volatility as a function of temperature, and their chemical composition. In this lecture these new measurement methodologies will be described, and our recent measurements will be discussed.