AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
The Absorption Enhancement of Soot Particles from Biomass Burning in the Presence of Aromatic SOA
ANTONIOS TASOGLOU, Georges Saliba, R. Subramanian, Spyros Pandis, Carnegie Mellon University
Abstract Number: 454 Working Group: Aerosol Chemistry
Abstract Smog chamber experiments were conducted to investigate the changes of the physical properties and chemical composition of soot particles from biomass burning emissions exposed to aromatic secondary organic aerosol (SOA) and to their further chemical aging. A major focus of the study was the absorption enhancement of black carbon (BC) particles due the coating of the soot particles with aromatic SOA. This coating and the change of the oxidation state of the organic aerosol can result in the enhancement of the absorption of solar radiation by biomass burning BC particles and the production of brown carbon (BrC). In our experiments we investigated emissions from the burning of European white birch bark using an environmentally efficient cook stove. Aromatic SOA was produced by the addition of aromatic volatile organic compounds (VOCs) and their reaction with hydroxyl radicals under high and low NOx conditions. A suite of instruments was used including a Soot Particle Aerosol Mass Spectrometer (SP-AMS) and a Single Particle Soot Photometer (SP2), for the mass concentration and the chemical characterization of the particles. For the study of the optical properties of the particles, we used an aethalometer and a green and a blue photoacoustic extinctiometer (PAX). The changes in particle mass concentration and the chemical composition of the particles in comparison to the absorption enhancement were investigated. Changes in the absorption wavelength dependence were examined for the possible existence of BrC.