Dr Marie-Fanny Racault, School of Environmental Sciences, University of East Anglia
Dr BB Cael, National Oceanography Centre
Marine ecosystems play a key role in regulating the Earth’s climate. Marine ecosystems live largely at the ocean’s surface. Their activities generate a flux of carbon between the ocean surface and the deep ocean, so-called export flux, that modulates atmospheric CO2 in the long-term. The most recent global observations reveal that the bulk distribution of plankton populations tends to become more patchy with increasing size of micro-organisms. This suggests a change from small organisms such as picophytoplankton forming a constant background biomass, to large organisms such as jellyfish going through bloom and bust cycles (Buitenhuis et al 2013). Yet, even the most complex models (Le Quéré et al 2016) fail to reproduce the observed increasing patchiness.
This PhD project aims to better characterise the linkages between patchiness and the size of plankton organisms, identify their drivers, and determine how patchy distributions may be related to carbon export events and influence the ocean carbon cycle. The PhD candidate will examine patchiness using new marine observations such as satellite data (Racault et al 2017), abundance (Buitenhuis et al2013), imaging (Lombard et al 2017) and genomics. The candidate will explore the environmental and ecosystem processes driving the regional and temporal variations in the observed patchiness using both machine-learning techniques and results from a process-based global ecosystem model named PlankTOM12. Finally, the candidate will help improve the representation of patchiness in the PlankTOM12 model that currently represents organisms across all sizes from viruses to bacteria, to six groups of phytoplankton and five zooplankton (Le Quéré et al 2016).
The PhD candidate will be part of a dynamic research group and contribute to the development of a cutting-edge model of the ocean carbon cycle used for understanding climate change and the Earth System. The successful candidate will receive specific training and have opportunities to interact with an international group of experts and attend Greenocean workshops.
This project is particularly suited for candidates with first degrees in any sciences and an interest in marine ecosystems and climate change. Enthusiastic individuals with experience in computer-based analysis are encouraged to apply.