Climatic impacts of biodiversity in marine calcifying phytoplankton (NERC GW4+ DTP Projects 2018-19)

The project will assess the impact of coccolithophore diversity on the carbon cycle for modern, future and past climates. It will evaluate the contribution of coccolithophore main types on the different carbon pumps mostly using computer modelling. While current models only account for the smallest and ominpresent coccolithophore Emiliania huxleyi, it is unclear if this type dominates carbon exports, especially since larger species tend to sink faster. What is then the contribution of larger coccolithophores on the biological and carbonate pumps today and how can it vary in the future and the past? The student will use the innovative and successful marine ecosystem model DARWIN to represent the diversity of coccolithophores, in which plankton population self-assembles in response to the environment, resource competition and predefined physiological trade-offs2-4. The student will combine DARWIN with a variety of climate models (MITgcm, GENIE) to look at different climates. Opportunities to do laboratory experiments will also arise with our CASE partner MBA, where they will examine the physiological responses of different coccolithophore species to help parameterise the DARWIN model. Finally, this project will occur in synergy with our international NERC/NSF project which investigates coccolithophore calcification, and with which the student will closely interact.