skip to content

Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: Alexandra Turchyn, Earth Sciences

Co-Supervisor: Chiara Giorio, Chemistry

Brief summary: 
Using new laser spectrometers the student will explore how the production and consumption of methane changes under different agriculture management practices.
Importance of the area of research concerned: 
Understanding the sources and sinks of methane in wetland ecosystems remains one of the least understood factors under anthropogenically driven climate change. Carbon sequestration in agricultural soils has huge potential, and changes made to agricultural practices may allow for enhanced carbon storage potential, allowing the UK to reach its net zero climate goals. However, alternatives in land management practice of agricultural soils, including changes in drainage networks, water supply, or other land use change may also drive anaerobic soils towards the production of methane. Methane is produced through the reduction of organic carbon, termed acetoclastic methanogenesis, or through the direct reduction of CO2, termed hydrogenotrophic methanogenesis, in the absence of oxygen. Water logged soils, therefore are one of the largest sources of methane production globally. Methane production is enhanced close to aerobic environments as aerobic organisms can breakdown larger organic molecules into the labile organic compounds needed to fuel methane production. Therefore changes in the water table may all impact the overall methane made within a managed agricultural soil environment.
Project summary : 
This studentship will leverage the recent establishment of the LASER-ENVI laser spectrometry isotope facility, funded through a NERC capital call, to measure the carbon and hydrogen, and clumped isotopic composition of methane during the field experiments. The clumped isotopic composition of methane gives unprecedented insight into the source of the methane and may highlight how changes in land use practices yield changes in the source of methane. It has been recognised for decades that the carbon and hydrogen isotope ratios in methane hold insight into the various sources of methane, with methane produced by microbes having more 12C and 1H than methane produced through heating and thermal cracking.
What will the student do?: 
In this project the student will work alongside the postdoc based in atmospheric chemistry, who will be monitoring changes in the concentration of methane and CO2, to add the measurement of the clumped isotopic composition of methane. The student will be based in Earth Sciences, the home of the equipment in the LASER-ENVI facility. The student in this project will make additional measurements of the clumped isotopic composition and will work alongside the postdoc working in atmospheric chemistry, who will be designing new greenhouse gas sensors and monitoring changes in the concentrations of greenhouse gases during the field experiments and experimental work with land use changes. These measurements will offer a different dimension to the greenhouse gas measurements that are part of the core proposal. When successful, these measurements and this studentship will add an interesting environmental geochemistry and geomicrobiology dimension to UCAM-RESTORE. The student will join a highly multidisciplinary research team in the Turchyn lab, who span analytical isotope geochemistry and numerical modelling of environmental problems.
References - references should provide further reading about the project: 
Shoemaker and Schrag - Subsurface characterization of methane production and oxidation from a New Hampshire wetland, Geobiology https://doi.org/10.1111/j.1472-4669.2010.00239.x
Zazzeri et al - Plume mapping and isotopic characterisation of anthropogenic methane sources, Atmospheric Environment - https://doi.org/10.1016/j.atmosenv.2015.03.029
Bhatia et al., Inventory of methane and nitrous oxide emissions from agricultural soils of India and their global warming potential - Current Science Vol. 87, No. 3 (10 August 2004), pp. 317-324 (8 pages)
Applying
You can find out about applying for this project on the Department of Earth Sciences page.
Dr Chiara Giorio
Dr Alexandra (Sasha) Turchyn