AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
New Particle Source Identification in Antarctica – Results from the 2ODIAC Field Campaign
Michael Giordano, Lars Kalnajs, Anita Avery, J. Doug Goetz, Sean Davis, Terry Deshler, Anondo Mukherjee, Andrew Slater, PETER DECARLO, Drexel University
Abstract Number: 316 Working Group: Remote and Regional Atmospheric Aerosols
Abstract Understanding the sources and evolution of aerosols is crucial for constraining the impacts that aerosols have on a global scale. One of the major outstanding questions in aerosol science is the source and evolution of the Antarctic aerosol population. Real-time, high-resolution chemical speciation is necessary to identify aerosol sources but this data is lacking over the continent. However, the 2ODIAC (2-Season Ozone Depletion and Interaction with Aerosols Campaign) field campaign in 2014 and 2015 saw the first ever deployment of a real-time, high resolution aerosol mass spectrometer (HR-ToF-AMS) to the continent. Data from the AMS, and a suite of other aerosol and meteorological instruments, is used to investigate the relative importance of sulfate to the total Antarctic aerosol number population. The sulfate contribution is shown to undergo three distinct phases as seasons shift from winter to summer. The first phase, in the Austral winter, is dominated by highly aged sulfate particles which comprise the majority (>50%) of the aerosol population. The second phase, previously unidentified, is the generation of a sub-40nm aerosol population of unknown composition when daily high solar irradiation is between 100-300 Wm-2. The third phase is marked by an increased importance of non-sea-spray derived sulfate to the total aerosol population (oxidation of dimethyl-sulfide, DMS). The conclusions that the third phase is due to phytoplankton production are constrained using PMF analysis on the AMS data set.