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Job Description: Three MSc’s, three PhD’s and one Post Doctorate opportunity in the SOCCO bio-optics project

Introduction:Phytoplankton primary production and carbon export to the deep ocean, “the biological pump” is considered a major contributor to the Southern Ocean CO2 sink removing ~33% of the global organic carbon flux each year. Climate models and decadal data sets predict changes in the earth’s climate that will influence the effectiveness of the Southern Ocean CO2 sink through adjustments to sea surface temperature, stratification and mixing, all of which affect the nutrient and light supply necessary for phytoplankton production (and associated carbon export). The regional character of the sensitivity of biological production to predicted changes in the earth’s climate are however unknown, which impedes our ability to predict the future response of the Southern Ocean’s biological carbon pump to a changing climate. The following research projects aim to derive information from ocean colour and autonomous platforms in the Southern Ocean to provide new insight into ecosystem function.

Study 1:Two MSc projects in measuring rates of phytoplankton primary production in the Southern Ocean using 14C and 15N isotope techniques. These projects will measure rates of new, regenerated and total primary production in the Southern Ocean and interpret the results in context of the physical and chemical environment that the phytoplankton community are living in. The aim of this research is to better understand the response of the biological pump to changes in light and nutrient availability. Requirements: A background in biological sciences advantageous (e.g. botany, marine biology).

Study 2:One MSc project that analyses high resolution bio-optics data sets from gliders and floats in order to improve our understanding of the seasonal progression of the phytoplankton community in the subantarctic Southern Ocean. Bio-optical sensors (fluorescence, backscattering, PAR) on autonomous platforms (gliders / floats) can be converted to biogeochemical parameters (e.g. phytoplankton biomass, carbon content, size, physiology, productivity) using empirical relationships and simple models. These data will be analysed in conjunction with the underlying physics to assess the phytoplankton community response to small scale variability in ecosystem physical drivers in the subantarctic Southern Ocean. Requirements: A background in maths, physics or oceanography advantageous. Mathematical programming skills (e.g. MatLab) essential.

Study 3:One Phd project that makes high resolution ship board underway estimates of Particulate Organic and Inorganic Carbon (POC and PIC respectively) using bio-optical measurements of backscattering and intermittent acidification. The relationship between PIC distribution and total particulate backscattering will be examined in order to determine the importance of calcium carbonate producing coccolithophores to the overall optical properties of the Southern Ocean. Requirements: Numerate with mathematical programming skills (e.g. Matlab). Some knowledge of bio-optics advantageous.

Study 4:One PhD or MSc project that calibrates and develops processing scripts to determine high resolution underway spectral absorption from the Trios OSCAR (Online hyperspectral integrating cavity absorption meter) and integrates the instrument into the WetLabs underway ac-s processing for particulate and dissolved absorption. The spectral nature of the light emerging from the world’s oceans is intrinsically linked to the biogeochemical constituents of ocean waters. Remotely sensed ocean colour data thus represents a vast resource of information through the use of schemes which relate optical measurements of absorption and scattering to phytoplankton properties such as concentration, size and carbon content. This project has scope to address either instrument characterisation with the optronics group or to evaluate the utility of the absorption data for phytoplankton community composition. Requirements: Numerate with mathematical programming skills (e.g. Matlab). A background in optronics advantageous.

Study 5:One PhD project that assesses the variety of algorithms that currently exist for determining phytoplankton community characteristics from satellite data and develops and applies new analytical Equivalent Algal Populations (EAP) model to Southern Ocean data to retrieve information on functional type, size, carbon content and physiology and validates the output with in situ data. In many cases, remotely sensed data are the only systematic observations available for chronically under-sampled marine systems such as the polar oceans. Given the growing importance of remote sensing in the trajectory of Southern Ocean ecosystem understanding, it is necessary that we maximise the value of these observations by developing ecosystem-appropriate, well characterised products. Current ocean colour algorithms applied to Southern Ocean data sets tend to perform badly, due largely to their parameterisation with low-latitude bio-optical data sets whose properties differ from those of the Southern Ocean. The aim of this project is to develop and apply emerging techniques to derive optimized and regionally robust information from ocean colour in the Southern Ocean in order to provide new insight into ecosystem function. The EAP model places emphasis on explicit bio-physical modelling of the phytoplankton population as a holistic determinant of Inherent Optical Properties (IOP); derived from Standard size distributions of algal cells equivalent to natural populations, with optical properties calculated from two-layered spherical models (Robertson-Lain et al. 2014, Evers-King et al. 2014). This algorithm will be further developed to include IOP variability from size, carbon content and physiology and applied and tested in the relatively low biomass Southern Ocean. A key focus is the ability to assess the event, seasonal and inter-annual variability in ecosystem physical drivers and their biogeochemical response. This in turn will allow us to improve our understanding of environmental forcing mechanisms that regulate plankton communities and their role in mediating carbon exchange between the atmosphere and the ocean interior. Requirements: Numerate with mathematical or statistical programming skills (e.g. Matlab). Some knowledge of bio-optics advantageous.

We invite applications for a number of post-graduate study opportunities within the SOCCO Programme, which is a partnership between CSIR and a number of academic institutions. MSc and PhD applications are restricted to South African students but the Post-Docs are open. SOCCO is committed to supporting CSIR and partner-institutions in meeting the goals of national redress in science and engineering

Expression of Interest:Please send CV as expression of interest to: Dr Sandy Thomalla at