AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Biologically Mediated Control of Marine Cloud Condensation Nuclei Concentrations
XIAOFEI WANG, Kathryn Mayer, Mitchell Santander, Jon Sauer, Camille Sultana, Kimberly Prather, University of California, San Diego
Abstract Number: 416 Working Group: Aerosol Chemistry
Abstract Previous field studies suggest that cloud formation in the marine atmosphere may be linked to biological activity in seawater. Two types of marine cloud condensation nuclei (CCN) are nascent sea spray aerosol (SSA), produced by breaking waves, and secondary marine aerosol (SMA), produced when semi or low volatile gas phase compounds from the oceans partition onto particles. It has been hypothesized that particle composition can be modulated by biological activity in seawater. However, it is still unclear to what extent biological activity plays a role in affecting SSA composition. To elucidate this question, we studied both SSA and SMA production during a mesocosm experiment. We initiated a phytoplankton bloom in 2,400 liter of natural seawater. Nascent SSA were produced using a plunging waterfall in a marine aerosol reference tank (MART). SMA were produced by oxidizing the gaseous emissions from the seawater in an oxidative flow reactor (potential aerosol mass flow reactor, PAM). The production flux and hygroscopicity parameter (κ) of SSA were measured and the relative contribution to CCN was calculated. In addition, we also studied the mass yield, chemical composition, and hygroscopicity parameter (κ) of SMA from the oxidative flow reactor. Our result suggests that marine biological activity can play an important role in modulating marine cloud properties through secondary reaction processes that lead to SMA.