Supervisors: Mark Moore (lead, UoS), Matt Mowlem (NOC), Tom Bibby (UoS), Anna Hickman (UoS), Kevin Oxborough (Chelsea Technologies Group)
Oceanic phytoplankton are responsible for approximately half the primary production on Earth. These microbes hence constitute both the base of the marine food-chain and a crucial component of the planetary biogeochemical cycles of carbon and nutrients. Phytoplankton primary production varies widely across the oceans from spatial scales of a few km associated with physical phenomena such as fronts and eddies, to the strong gradients observed across whole ocean basins. Moreover, phytoplankton photosynthetic rates respond to environmental forcing in the form of light and nutrient availability at sub-daily through climatic time scales. However, our understanding of this spatio-temporal variability in phytoplankton photosynthesis is severely hampered by extreme undersampling of marine systems, which ultimately limits confidence in our best estimates of the magnitude of oceanic productivity. Active chlorophyll fluorometry represents a groundbreaking technology with the potential to overcome this sampling problem through facilitating high quality in situ measurements of photosynthetic rates; especially if such instrumentation can be developed to the point where it can be routinely deployed using autonomous observational platforms. Currently available instrumentation is inadequate for the purpose. The current project aims to fill this crucial technological gap, facilitating improved understanding of the variability of oceanic photosynthesis across unprecedented scales.
The studentship will be associated with a recently funded project to develop a new generation of active chlorophyll fluorometers designed specifically to facilitate high resolution in situ measurements of oceanic primary production using autonomous deployment platforms, including surface vehicles, autonomous underwater vehicles (AUVs) and gliders. The student will initially be involved in shore based laboratory comparison of the novel instrument with more established techniques for the measurement of phytoplankton productivity. Subsequently, the student will have the opportunity to use the new sensor at sea during ocean going research cruises and will participate in the initial trial deployments on shore launched marine autonomous instrumentation. The student will thus undertake the first scientific investigations using this new instrumentation. The novel new data acquisition techniques will be compared with more traditional methods. Primary production measurements collected at unprecedented scales will then be compared with simultaneously collected information on biological, chemical and physical drivers to develop a new understanding of how this fundamental metabolic process is controlled in the ocean. The student will also explore opportunities for merging the new information gained from such autonomous instrumentation with the repeated observations made by space-borne ocean colour satellites.
The NEXUSS CDT provides state-of-the-art, highly experiential training in the application and development of cutting-edge Smart and Autonomous Observing Systems for the environmental sciences, alongside comprehensive personal and professional development. There will be extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial / government / policy partners. The student will be registered and hosted at the University of Southampton, and based within Ocean and Earth Science at the National Oceanography Centre Southampton.
Specific training will include familiarisation with the techniques of active chlorophyll fluorometry for derivation of photosynthetic rates using both established laboratory and shipboard instrumentation and the new sensor, alongside training in a wide variety of other in situ and remote sensing based techniques for estimation of oceanic primary production. The student will join an active world class research group at Southampton using cutting edge techniques to study marine microbes and the biogeochemical cycles they drive, while also being able to spend time with a leading UK company in the marine sensor development sector.
Background Reading:
To apply for this project, use the: apply for a NEXUSS CDT studentship