About the Project
The gas carbonyl sulphide (COS), from natural (the ocean, anoxic sediments) and anthropogenic sources (coal, biomass burning, viscose-rayon industry), reaches the stratosphere where it substantially affects ozone chemistry and climate. It is removed by terrestrial plants in a manner analogous to that of CO2, and has therefore been used as a unique tracer of carbon cycling by the terrestrial biosphere. Recently we used it to examine the causes of low CO2 in the 16th/17th century Little Ice Age (LIA) from measurements in ice cores, which indicated a reduction in both terrestrial photosynthesis and respiration at that time. This potentially has profound implications for future CO¬2 cycling in a warming world. However, a lack of understanding of what controls COS sources and sinks to the atmosphere has hampered attempts to accurately represent and simulate these processes in numerical models of present and past atmospheres.
This project will address some of these issues, utilising existing data records and novel measurements that the student will make on COS in ice cores, and on air samples that we collect from around the world. They will use these in a numerical model (GEOS-Chem) to arrive at new understandings of the global COS budget.
This project will suit a student with interests in both modelling and laboratory measurements. Training in ice core processing and trace gas analysis will be given at the British Antarctic Survey and UEA. Assistance in interpreting these records will come from co-investigators in Italy and Australia. Measurements will also be made on air samples collected from around the world, from the tropics to poles.
The student will collate data and information relevant to improving the representation of COS fluxes used in global models and conduct a range of model simulations from simple hemispheric box models up to full 3-dimensional atmospheric chemistry-transport model runs.
No prior experience in trace gas analysis is necessary, and training in advanced numerical modelling will be provided. A basic knowledge of chemistry is desirable, as is some prior experience of programming.
A minimum Upper Second Class BSc in Environmental Science, Physics, Chemistry, Engineering, or similar degree is required.
Funding Notes
This project has been shortlisted for funding by the EnvEast NERC Doctoral Training Partnership, comprising the Universities of East Anglia, Essex and Kent, with twenty other research partners.
Shortlisted applicants will be interviewed on 14/15 February 2017.
Successful candidates who meet RCUK’s eligibility criteria will be awarded a NERC studentship. In most cases, UK and EU nationals who have been resident in the UK for 3 years are eligible for a full award. In 2016/17, the stipend was £14,296.
For further information, please visit www.enveast.ac.uk/apply
References
i. Montzka, S.A., P. Calvert, B.D. Hall, J.W. Elkins, T.J. Conway, P.P. Tans and C. Sweeney, J. Geophys. Res., 112, doi:10.1029, 2006JD007665, 2007.
ii. Rubino, M., D. M. Etheridge, C. M. Trudinger, C. E. Allison, P. J. Rayner, I. Enting, R. Mulvaney, L. P. Steele, R. L. Langenfelds, W. T. Sturges, M. A. J. Curran & A. M. Smith, Low atmospheric CO2 levels during the Little Ice Age due to cooling-induced terrestrial uptake, Nature Geoscience, doi:10.1038/ngeo2769
iii. Sturges, W.T., Penkett, S.A. Barnola, J.M. Chappellaz, J. Atlas, E. and Stroud, V., A long-term record of carbonyl sulfide (COS) in two hemispheres from firn air measurements, Geophysical Research Letters, 28, 21, 4095-4098, 2001.
iv. Suntharalingam, P., A.J. Kettle, S.M. Montzka, and Daniel J. Jacob.. Global 3-D model analysis of the seasonal cycle of atmospheric carbonyl sulfide: Implications for vegetation uptake, Geophys. Res. Lett., doi:10.1029/2008GL034332, 2008.
v. Suntharalingam, P., J. Randerson, N. Krakauer, D.J. Jacob and J.A. Logan, Influence of reduced carbon emissions and oxidation on the distribution of atmospheric CO2: Implications for inversion analyses, Global Biogeochemical Cycles, doi: 10.1029/2005GB002466, 2005
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