10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Simultaneous Water Uptake and Size-resolved Bounce Measurement of Secondary Organic Aerosols
DEVOUN STEWART, David De Haan, Richard Gardner, University of San Diego
Abstract Number: 1101 Working Group: Aerosol Chemistry
Abstract The phase change of secondary organic aerosols in the atmosphere is of significant scientific interest because of its effects on climate. The effect of aerosols on climate is closely linked to aerosol interaction with water. Solid aerosols can uptake water under humid conditions, which causes them to liquefy. Under these conditions, the optical properties of aerosols, which depends on its size and phase, will change. The light scattering properties of aerosols increase significantly when particle absorbs water. Since the climate effects of aerosols are closely tied to interactions with water, we developed an instrument capable of simultaneous aerosol water uptake and size-resolved bounce measurements. This instrument uses two SMPS system connected to a MOUDI impactor to simultaneously measure both particle growth and bounce factors at various controlled relative humidity. The size-resolved bounce measurements allow us to determine how much water uptake is required for the aerosol to liquefy. In this presentation, we will present results of the size-resolved phase change and growth factors of different secondary organic aerosols. Our instrument was validated by measuring the growth and bounce factor of ammonium sulfate aerosols.