Environmental Factors Driving Sea Spray Aerosolization-- A Laboratory-Scale Breaking Wave Case Study
RAYMOND LEIBENSPERGER III, Kimberly Prather, Grant B. Deane, M. Dale Stokes, Christopher Lee, Meinrat O. Andreae, Jena Herbst, Justin Hamlin, Ke' La Kimble, Charbel Harb, Greg Sandstrom, Joseph Mayer, Rob Klidy, Eric Pham, Elizabeth Pogue, University of California San Diego
Abstract Number: 536
Working Group: Aerosol Physics
Abstract
Sea spray aerosols (SSA) are among the most ubiquitous naturally produced aerosols on the planet and drive our climate through poorly constrained aerosol-cloud interactions. Despite the air-sea interface being investigated for over half of a century, the complex air-sea interface is difficult to characterize in situ, leading to large variance in literature estimates. To combat this, the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel enables unprecedented control of environmental variables, allowing for high-fidelity studies of SSA emissions. Here, we briefly detail three experiments working to understand environmental drivers independent of one another. First, we used heavily filtered seawater to investigate the impact of wind speed on SSA. Then seawater inoculated with locally-sourced phytoplankton allowed us to investigate the impact of a mesocosm on SSA production. Finally, heavily filtered seawater underwent a large change in temperature (2 to 23ºC) to elucidate the impact of temperature on SSA. It was found that wind speed non-linearly increased SSA emissions, necessitating more studies covering a range of wind speeds from the global average (around 6 m s-1) to storm conditions in the Southern Ocean (exceeding 20 m s-1). Agreeing with previous work in wave channels, biological activity did not have a statistically significant effect on SSA emissions under low or high wind conditions. Interestingly, temperature was found to be inversely related to sea spray aerosolization, which is one of the least studied influences in literature despite being a key driver in climate models. These environmental drivers are not concisely characterized in the literature, so these results together offer a state-of-the-art comprehensive exploration into SSA production in a realistic breaking wave proxy. While there is still large variability to be accounted for by mixing these factors, these results further constrain SSA flux estimates, enabling model parameterization updates, potentially improving model performance.