Abstract

New particle formation, the spontaneous creation of new nanometer-sized particles in the atmosphere, is often the dominant source of particles in the remote regions and could play a crucial role in the Earth's climate. In this talk I will describe our efforts to understand the species and mechani... Show moreNew particle formation, the spontaneous creation of new nanometer-sized particles in the atmosphere, is often the dominant source of particles in the remote regions and could play a crucial role in the Earth's climate. In this talk I will describe our efforts to understand the species and mechanisms that are responsible for the formation and growth of nanometer-sized particles using two instruments developed in our laboratories: the Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS), an instrument capable of real time measurements of the molecular composition of nanoparticles as small as 6 nm in diameter, and the Cluster Chemical Ionization Mass Spectrometer (Cluster-CIMS), which can detect neutral, atmospheric molecular clusters. Results from laboratory a-pinene ozonolysis experiments point to the presence of high molecular weight gas-phase species that may contribute to the growth of newly formed nanoparticles. Ambient measurements confirm these observations, while in addition show organic salt formation also plays an important role. Show less