SOSO2

Southern Ocean Sulfur Dioxide Study

15 October 2024 - 15 February 2025

Lead Scientist: Peter Edwards

Observatory: AMF

Despite mixing ratios in the low parts per trillion (pptv) range, sulphur dioxide (SO2) plays a central role in the formation of cloud condensation nuclei in pristine marine environments. To date, real-time measurements of SO2 in pristine locations have been limited by the lack of instrumentation capable of measuring these low levels. Previous measurements in these environments have required long sampling periods (>7 days) to achieve the required detection limits, making process level studies difficult. The University of York’s recently developed LIF-SO2 instrument uses laser induced fluorescence to make highly sensitive measurements of SO2, with single pptv precision on minute timescales. This instrument is orders of magnitude more sensitive than existing commercial SO2 detectors and is the ideal tool for investigating SO2 and its impact on cloud formation in locations such as the Southern Ocean. This project will deploy the York LIF-SO2 at kennaook/Cape Grim to generate a unique dataset and complement coincident measurements of gas phase and aerosol properties at the site. This additional information on a key aerosol precursor will directly contribute to an improved understanding of cloud formation in this most pristine of environments, and ultimately help address a major bias in current global climate models.