AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Biological Impacts on Carbon Speciation and Morphology of Laboratory Generated Sea Spray Aerosols
Don Pham, Rachel O'Brien, Matthew Fraund, Daniel Bonanno, Olga Laskina, Charlotte Beall, Kathryn Moore, Sara Forestieri, Xiaofei Wang, Chris Lee, Camille Sultana, Vicki Grassian, Christopher Cappa, Kimberly Prather, RYAN MOFFET, University of the Pacific
Abstract Number: 495 Working Group: Aerosol Chemistry
Abstract An isolated wave channel facility was used to generate sea spray aerosol during a one month mesocosm study. Two consecutive phytoplankton blooms occurred and sea spray aerosol were sampled throughout. Scanning Transmission X-Ray Microscopy coupled with Near Edge X-Ray Absorption Fine Structure (SXTM-NEXAFS) spectroscopy was used to determine spatially resolved molecular information for carbon within individual particles. Morphological changes and organic enrichment in the emitted particles occurred during two blooms. The extent of organic enrichment correlates with the occurrence of aliphatic-rich organic species as detected by an intense C1s→σ(C-H)* excitation. These aliphatic-rich species had a strong association with graphitic carbon, detected by a C1s→σ* exciton excitation. This enrichment was unique to particles collected in the aerodynamic size range 0.18-0.32 µm and corresponded with the decrease in hygroscopicity. Aliphatic organics can significantly suppress the particle hygroscopicity when they replace salt, thus influencing the effect sea spray aerosol particles have on light scattering and cloud formation.