AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Ocean Biology Effects on Saccharide Composition in Sea Spray Aerosol
ELIAS HASENECZ, Wyeth Gibson, Samantha Kruse, Jon Sauer, Kathryn Mayer, Chris Lee, Kimberly Prather, Elizabeth Stone, University of Iowa
Abstract Number: 785 Working Group: Carbonaceous Aerosol
Abstract Ocean biology impacts the chemical composition of sea spray aerosol (SSA) and consequently properties like cloud formation. Saccharides comprise a significant portion of SSA organic mass and are examined to evaluate how ocean biology impacts SSA’s physicochemical properties. Sub and supermicron SSA was collected during two phytoplankton blooms, one with added heterotrophic bacteria. Saccharides were hydrolyzed, then separated and quantified by high performance ion chromatography with pulsed amperometric detection. Peak total saccharide concentrations were similar across the two mesocosm experiments and decreased in SSA after the phytoplankton bloom by a factor of up to 8.5. This decrease was more prominent by a factor of two times in bacteria spiked mesocosms suggesting added bacteria overall decreased saccharide levels by scavenging. This decrease was greatest for glucose (by 3.5 times), suggesting that glucose was readily scavenged by bacteria. In contrast, the decrease in galactose concentrations after the phytoplankton bloom was not enhanced by the bacteria addition, which is attributed to its presence in less labile polymeric materials. Although arabinose is associated with bacterial activity, there was no significant increase in its’ concentrations across two mesocosms. Instead, arabinose concentration decreased following the total saccharide trend. This finding suggests that the scavenging of arabinose outweighed release by plankton and bacteria. The observed temporal trends in saccharide levels in SSA are being further examined with respect to saccharide monomer concentrations in sub-surface water, fractionated by size using ultra-filtration. Measurements of inorganic ions will be used to examine the enrichment of saccharides and divalent cations in SSA under varying biological conditions.