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Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: Sasha Turchyn, Earth Sciences

Co-Supervisor: Marie Edmonds, Earth Sciences

This is a CASE project with Aerodyne

Brief summary: 
The sulfur isotopic composition of hydrogen sulphide and sulfur dioxide will be developed using laser spectrometers in conjunction with Aerodyne and then applied to environmentally relevant samples.
Importance of the area of research concerned: 
Sulfur gases are redox sensitive, reactive, important in Earth's radiative balance and cloud condensation nuclei; understanding the fluxes of sulfur gases from various environments and volcanoes is thus a critical component and a large unknown in climate models as well as in the global sulfur cycle. The isotopic composition of these gases could help pin their sources, but currently the analysis field-collected sulfur gases is analytically challenging. The ability to collect and isolate these samples in the field, and return them to the lab for isotopic and concentration analysis would revolutionise our ability to understand the fluxes of sulfur from the mantle or from terrestrial environments. This would be a key input to our understanding of the importance of these fluxes in the global biogeochemical sulfur cycle, Earth's radiative balance, and the role that sulfur might play in both past and future climate change. Being able to measure sulfur gas concentrations (both hydrogen sulfide and sulfur dioxide) and their isotopic compositions will dramatically impact our ability to determine the ultimate source of these gases.
Project summary : 
Aerodyne is a world-leading expert in developing the use of laser spectrometers for the isotopic analysis of atmospheric gases. They are confident that with some analytical development it will be possible to analyse the sulfur isotopic composition of various gases using a laser spectrometer that is being purchased as part of the LASER-ENVI suite of laser spectrometers. Once developed it will be possible to acquire drone samples from volcanic fumaroles and analyse their sulfur gas concentration and isotopic composition. It will also be possible and useful to measure sulfur gas fluxes in chambers from soils, to constrain the flux of volatile sulfur compounds from sediments to the atmospheric sulfur cycle.
What will the student do?: 
The student will spend the first six months of the project working with the Aerodyne team in Boston MA to develop the laser spectrometer for sulfur isotopic analysis of hydrogen sulfide and sulfur dioxide. Then the student will return to Cambridge with the working equipment and get the spectrometer installed and established as part of the LASER-ENVI suite of spectrometers. The objective then will be to test the equipment with a suite of environmentally relevant sulfur gases from two major sources of sulfur gases to the atmosphere. First the student will travel to sample sulfur rich volcanic gases using samplers on drones - this would be done first as the concentration of sulfur gases is typically higher in these environments. Then the student could analyse the concentration and isotopic composition of volatile sulfur gases that are released in marginal marine environments. These results can be integrated into global atmospheric chemistry and global climate models as the fluxes of sulfur bearing gases remains one of the key unknowns for future climate change.
References - references should provide further reading about the project: 
Kutuzov et al., The molecular and sulfur isotope distribution of volatile compounds in natural gases and condensates from Alberta, Canada, Organic Geochemistry Vol 151, 104129, 2021
Oppenheimer et al., Sulfur Degassing From Volcanoes: Source Conditions, Surveillance, Plume Chemistry and Earth System Impacts, Reviews of Mineralogy and Geochemistry, Vol 73, pp 361-471, 2011
Hitchcock and Black, 34S/32S Evidence of biogenic sulfur oxides in a salt marsh atmosphere, Atmospheric Environment, Vol 18, pp 1-17, 1984
Applying
You can find out about applying for this project on the Department of Earth Sciences page.
Dr Alexandra (Sasha) Turchyn
Department of Earth Sciences Graduate Administrator