Tiny critters, huge impacts: Ocean microbes, climate, and health

It is critical to improve our understanding of the impacts of the ocean/atmosphere system on climate as Earth undergoes unprecedented change. Current models are limited in their treatment of marine aerosols, atmospheric chemistry, and clouds. A particularly challenging area involves determining the impact of ocean microbial emissions on the atmosphere. The ability to determine the impact of ocean biology on clouds and climate in field studies has been impaired by the additional complexities from added human pollution, even out over the open ocean. This lecture will provide an overview of unique ocean/atmosphere-in-the laboratory studies in the NSF Center for Aerosol Impacts on Chemistry of the Environment (CAICE; https://caice.ucsd.edu) designed to unravel the composition of the marine atmosphere with a major focus on the factors controlling the chemical mixing state, cloud formation, and ice nucleating ability of marine aerosols. Over the past decade, CAICE scientists have been able to successfully transfer the full physical, chemical, and biological complexity of the ocean/atmosphere system into the laboratory at Scripps Institution of Oceanography. This presentation will highlight results obtained using this unique approach and how they are now being used to explain marine field observations and improve climate models. This lecture will describe how CAICE studies have been able to finally account for changes in clouds in regions with phytoplankton blooms. This lecture will also discuss the new Scripps Ocean-Atmosphere Research Simulator (SOARS) that will use winds and waves to simulate the complex marine atmosphere boundary layer under varying scenarios of temperature, from tropical to polar, atmospheric gas phase concentrations, and ocean pH. SOARS will be able to simulate the current and future states of the ocean/atmosphere system thus uniquely capable of simulating Earth’s rapidly changing ocean-atmosphere system.  Finally, a discussion will be presented on recent field and laboratory studies investigating the factors controlling the ocean-to-atmosphere transfer of bacteria, viruses, and gases and the implications for the health of residents living in and near coastal regions. These studies are yielding insight into how our atmosphere and climate will change as climate and oceans warm.