Atmospheric Nanoparticles: Measurements and Observations
Jim Smith, Ph.D.
National Center for Atmospheric Research
Abstract:
In this talk, I will provide an overview of the latest measurement techniques used in the study of sub-50 nm diameter atmospheric aerosol, aka “nanoparticles.” I will review techniques for detecting and identifying the composition of neutral and charged aerosol as small as 1 nm in diameter, utilizing principles of condensational growth, charged particle and ion mobility, and mass spectrometry. I will also discuss nanoparticle generation methods that have facilitated improvements in instrumentation. With this understanding of the instruments employed in nanoparticle research, I will present some key observations from recent laboratory and field studies. These studies seek answers to such questions as “What are the mechanisms and species responsible for the formation of new particles in the atmosphere?” and “What are the effects of new particle formation on human health and climate?”
Biosketch:
Jim Smith is a scientist in the Atmospheric Chemistry Division at the National Center for Atmospheric Research (NCAR). He received his Ph.D. in Environmental Science and Engineering at the California Institute of Technology in 2000, and currently is head of the Ultrafine Aerosols Research Group at NCAR. His research interests focus on performing laboratory and field measurements in order to understand and quantify the mechanisms of atmospheric nanoparticle formation and growth. He is the developer of the Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS), an instrument that can measure the molecular composition of 8 to 50 nm diameter atmospheric aerosol at ambient concentrations.