CE509: Investigating the mechanisms of new particle formation and growth in the marine atmosphere on the coast of Namibia. (Lead supervisor: Chiara Giorio, Chemistry)

Marine ecosystems are important drivers of the global climate system. They emit volatile species into the atmosphere, involved in complex reaction cycles that influence the lifetime of greenhouse gases. They also emit sea spray and marine biogenic aerosols that affect the Earth's climate by scattering solar radiation and controlling cloud microphysical properties. A notable example is dimethyl sulfide (DMS), emitted by the marine biota; it is an efficient aerosol and cloud droplet producer. According to the CLAW hypothesis [1], DMS emissions are key in the establishment of a feedback loop between global warming, enhanced production of marine plankton, and increased emissions of DMS leading to production of aerosol particles that would cause cooling. The Benguela upwelling system, off the west coast of southern Africa, is a well-known ecosystem in which upwelling pulses of nutrient-rich waters induce high biological production. As a consequence of upwelling along the north coast of Namibia, phytoplankton blooms are frequent, leading to strong emissions of DMS and volatile organic compounds (VOCs) [2].