About the project
Aggregation of organic particles to form “marine snow” can produce significant export pulses that contribute to ocean carbon storage. This project will analyse unique datasets of biological glues, turbulence and particle characteristics collected in high latitude environments to assess the drivers of aggregation and quantify its influence on carbon export.
The biological pump transfers a significant amount of carbon dioxide to the deep ocean, via the export of organic carbon out of the upper ocean, often in the form of sinking marine snow aggregates. The size, shape and structure of marine snow particles all influence the rates at which they sink and are remineralised, with fast sinking particles increasing the potential for long-term carbon storage [1]. Isolated studies have found specific conditions where biological glues, which are sticky polysaccharides known as transparent exopolymer particles (TEP)[2], and/or turbulence [3] can promote aggregation and lead to changes in particle characteristics conducive to rapid sinking.
Initially, the student will analyse novel cruise datasets from the CUSTARD and PARTITRICS projects, which collected observations of turbulence, TEP and particle characteristics in the Southern Ocean and Iceland Basin. This provides an opportunity to assess the competing roles of biological glues and turbulence in promoting particle aggregation. With this dataset the student will test the hypothesis that higher TEP concentration and/or turbulence in the mixed layer leads to larger mean particle size, indicative of increased aggregation. With this as foundation, the student will be encouraged to choose the future direction of the project in line with their interests. The supervisors’ expertise could support several exciting avenues. For example, the student could develop a simple numerical model to test the influence of turbulence, TEP and particle morphology on particle fluxes, and/or analyse a new global particle size dataset to explore wider consequences for the ocean carbon cycle.
You will also be supervised by organisations other than the University of Southampton, including:
