Laboratory simulated atmospheric aging processes of combustion-generated soot particles
Poster PDF
Authors
Andrew Thomas Lambe — Aerodyne Research, Inc.
Adam Thomas Ahern — Aerodyne Research, Inc.
Timothy B Onasch — Aerodyne Research
Justin Wright — Boston College
David Croasdale — Boston College
Douglas R Worsnop — Aerodyne Research
Paul Davidovits — Boston College
Category
Aerosol Mixing State
Description
The climate forcing of particles containing absorbing material such as refractory black carbon (rBC) is complex because of the potential for positive and negative radiative forcing effects. To investigate the effect of chemical composition on CCN activity of rBC-containing particles, laboratory experiments were conducted in which ethylene flame soot particles were generated and exposed to OH radicals in a Potential Aerosol Mass (PAM) flow reactor over OH exposures equivalent to approximately one day to ten days of atmospheric oxidation. OH oxidation of the soot converted hydrophobic organic coatings to CCN-active hydrophilic molecules such as carboxylic acids.,As expected, soot particles thermally denuded of organic compounds are characterized by lower CCN activity. In a separate set of experiments, SOA was condensed on the soot particles and the enhanced CCN activity was measured. Implications of atmospheric aging of rBC-containing particles are discussed.Lead PI
Paul Davidovits — Boston College