Chemical Imaging of Biomass Burning Particles Present in the Summer Stratosphere

STEVEN SHARPE, Felipe Rivera-Adorno, Temitope Olayemi, Yaowei Li, Xiaoli Shen, Ryan Moffet, John Dykema, Frank Keutsch, Daniel Cziczo, Alexander Laskin, Purdue University

     Abstract Number: 306
     Working Group: Remote and Regional Atmospheric Aerosol

Abstract
The increasing size, severity, and frequency of wildfires has led to drastic increases in particulate matter concentrations in the troposphere. However, pyrocumulonimbuses (pyroCB) generated by large scale wildfire events perturb the environment and inject biomass burning organic aerosols (BBOA) into the lower stratosphere. We have applied chemical imaging techniques as part of the Dynamic Chemistry of the Summer Stratosphere (DCOTSS) campaign in order to determine the composition, morphology, and mixing state of stratospheric BBOA; evaluate the effects of BBOA on stratospheric chemistry; and assess the optical properties of stratospheric BBOA. Chemical imaging with Scanning Transmission X-Ray Microscopy coupled with Near Edge X-Ray Absorption Fine Structure (STXM/NEXAFS) has allowed us to calculate the organic mass fraction and mixing state of stratospheric BBOA and provided high and low limit estimates of total alkene reactions with ozone. Our results are correlated with online PALMS and DPOPs instruments deployed during research flights in the stratosphere.