AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Nanoparticle Formation in a Tandem Flow Tube Apparatus (TANGENT)
CHRIS STANGL, Justin Krasnomowitz, Qi Ouyang, Lee Tiszenkel, Shanhu Lee, Murray Johnston, University of Delaware
Abstract Number: 769 Working Group: Aerosol Chemistry
Abstract Atmospheric aerosols are well known to impact radiative forcing through both direct and indirect effects, however discrepancies between modeled and measured aerosol yields in the atmosphere remain a critical deficit in our ability to accurately predict future changes in climate. In this work, a Tandem Aerosol Nucleation and Growth ENvironment Tube (TANGENT) apparatus is used to study particle formation and growth. In the experiments described here, nanoparticles are generated by sulfuric acid-water nucleation in flow tube #1 (FT-1) using sulfur dioxide oxidation by OH as the source of sulfuric acid. Aerosol from FT-1 is sent into a second flow tube (FT-2) where it is mixed with α-pinene and ozone. Initial experiments were performed with mixing ratios in FT-2 on the order of 400 ppbv sulfur dioxide, 14 ppbv α-pinene and 10-400 ppbv ozone. Under these conditions, we find that both nucleation and growth occur in FT-2, and both processes depend strongly on the extent of sulfur dioxide oxidation by OH and/or the Criegee intermediate that are produced by α-pinene ozonolysis. The results give insight into the role of sulfur dioxide for enhancing ambient nanoparticle formation in plumes.