AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Using Ocean Biogeochemistry and Surface Activity to Improve Understanding of Regional Patterns in Sea Spray Chemistry
SUSANNAH BURROWS, Oluwaseun Ogunro, Amanda Frossard, Lynn Russell, Phil Rasch, Scott Elliott, Pacific Northwest National Laboratory
Abstract Number: 527 Working Group: Remote and Regional Atmospheric Aerosols
Abstract Surface-active organic molecules are strongly enriched in primary sea spray aerosol (SSA) as a result of their adsorption onto bubble films, and accumulation in the sea surface microlayer. A new modeling framework is presented that predicts the enrichment of organics in the aerosol on the basis of their surface activity. We utilize output from an ocean biogeochemistry model to describe the geographic distribution of several classes of organic compounds in the ocean. We assign chemical properties to each class based on laboratory measurements, and use the Langmuir adsorption isotherm to predict the organic mass fraction of the generated SSA. Recent observations across several ocean regions have lead to differing conclusions regarding the correlation of chlorophyll-a and SSA organic mass fraction. Our model predicts a strong positive correlation of chlorophyll-a and SSA organic mass fraction in nutrient-rich regions such as the North Atlantic, largely driven by the seasonal cycle, but less variability and a negatively correlated seasonal cycle in nutrient-poor regions such as the southeast Pacific. These results demonstrate that the new model can resolve certain apparent discrepancies between observations, and represents an advance in understanding how the drivers of SSA composition differ between ocean regions.