Dr Sarah Chadburn, University of Exeter Professor Iain Hartley, University of Exeter
The University of Exeter’s College of Engineering, Mathematics and Physical Sciences is inviting applications for a fully-funded PhD studentship to commence in September 2019 or as soon as possible thereafter. For eligible students the studentship will cover UK/EU/International tuition fees plus an annual tax-free stipend of at least £14,777 for 3.5 years full-time, or pro rata for part-time study. The student would be based in Mathematics in the College of Engineering, Mathematics and Physical Sciences at the Streatham Campus in Exeter.
Terrestrial ecosystems are currently absorbing more than a quarter of all the carbon dioxide we release to the atmosphere. The Paris climate agreement aiming to “hold the increase in the global average temperature to well below 2°C above pre-industrial levels” strongly depends on this uptake continuing. However, there are feedbacks in the Earth system that could reduce the amount of carbon that terrestrial ecosystems absorb. Potentially the most important is associated with the thaw of frozen soils in Arctic and Boreal ecosystems. These permafrost soils contain billions of tonnes of organic matter, and, once thawed, decomposition of the organic matter could result in substantial emissions of the greenhouse gases carbon dioxide and methane.
In this context, rapid thaw that results in the formation of lakes could play a critical role, with high emissions of the potent greenhouse gas, methane, potentially doubling the overall feedback to climate change. However, the process that results in the formation of lakes following rapid thaw, thermokarst, is not currently included in most models that are used to predict future rates of climate change. Therefore, future rates of warming may be under-estimated, and, thus, the extent to which our emissions would have to be reduced to avoid the most dangerous aspects of climate change.
The aim of this PhD is to address this fundamental uncertainty and to improve predictions of rates of methane release from thawing permafrost. This will be achieved by linking observations and simulations, developing novel methods to incorporate the process of thermokarst into the UK’s leading land surface model. The studentship would then aim to determine the importance of thermokarst and methane production in the permafrost feedback. As well as providing training in transferable skills including programming and modelling, the PhD offers opportunities for visiting Arctic field sites and collaboration with institutes in Norway and Germany, as well as the UK Met Office. Given the importance of the research topic and the novelty of the work, there are opportunities for generating high-impact publications.