Supervisors: Dr Paul Halloran, Prof Peter Challenor

Applications are invited for this EPSRC funded PhD studentship to commence as soon as possible. For eligible students the award will cover UK/EU tuition fees and an annual stipend (in 2013/14 this will be £13,726 for full-time students, pro rata for part-time students) for three years.

This project is one of a number that are in competition for funding. Studentships will be awarded on the basis of merit.

Successful applicants will be based within Geography (Streatham Campus) at the College of Life and Environmental Sciences, University of Exeter.

The sensitivity of global temperatures to changes in atmospheric CO₂ concentrations is uncertain, but grounded in well-understood physics. The link between CO₂ emissions and atmospheric CO₂ concentrations is however poorly constrained, and probably the biggest climate uncertainty after human behaviour (Booth et al., 2012).

Estimates of how this ratio of CO₂ emissions to atm. CO₂ concentrations, the ‘airborne fraction’ (Le Quere et al. 2009), will change in the future are obtained from Earth System Model (ESM) projections of land and ocean CO₂ uptake. These estimates are used to determine CO₂ emission targets.

But can we be confident in ESM projects of change in natural CO₂ sinks? The carbon-cycle components of these models are empirical, so lack inherent predictive skill (Halloran et al., 2010). It is therefore essential to calibrate models against past carbon-cycle change. This is however tricky – the most recent large-scale perturbation to the ocean carbon-cycle was the transition from the Last Glacial Maximum (LGM) to the Holocene. ESMs are too computationally expensive to run across this transition, so essentially remain uncalibrated.

You will therefore develop and apply cutting edge Bayesian statistical techniques to compare future projections from ESMs with palaeo- carbon-cycle records.

Initially identifying the relationship between large-scale observed ocean carbon cycle parameters and deep-sea sediment calcium carbonate concentrations, you will emulate a set of IPCC-class ESMs. Using ‘history matching’ and estimates of model discrepancy you will assess the models’ ability to match the carbon-cycle state – as recorded in deep-sea sediment cores – of the last Ice-Age.

Discarding those model projections inconsistent with Ice-Age conditions, we hope to narrow the range of future ocean-CO₂ uptake uncertainty.

This analysis will require you to work with and analyse ‘big data’ within Python and R. Experience with high-level scientific programing tools (e.g. Matlab), ideally within a Linux environment, is therefore essential.

You must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in maths, physics, chemistry, engineering, computing, or a numerically rigorous environmental science.

The studentship covers a stipend at the standard Research Council rate (£13,726 per annum for 2013-2014), research costs and tuition fees at the UK/EU rate for students who meet the eligibility requirements outlined by EPSRC (see http://www.epsrc.ac.uk/skills/students/help/Pages/eligibility.aspx). Students from EU countries who do not meet the residency requirements may still be eligible for a fees-only award. Students from outside of the EU would not be eligible for this award.

Closing date for applications is midnight on 8^th September 2013. 

For full project details, instructions on how to apply and a link to the application form, go to the apply button below