NERC GW4+ DTP PhD studentship: Land-sea climate correlations in the American tropics during two abrupt climate changes

This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP). At least 4 fully-funded studentships that encompass the breadth of earth and environmental sciences are being offered to start in September 2017 at Exeter. The studentships will provide funding for a stipend which is currently £14,296 per annum for 2016-2017, research costs and UK/EU tuition fees at Research Council UK rates for 42 months (3.5 years) for full-time students, pro rata for part-time students.

The last glacial period was punctuated by multiple abrupt climate fluctuations that are characterised by a magnitude of change up to 50% that experienced during a glacial-interglacial transition. The signature of these events is global although the magnitude and direction of change has been shown to be regionally variable. Variability in the Atlantic Meridional Overturning Circulation has been suggested as one of the primary drivers of abrupt climate variability. However, an alternative scenario where the modulation of abrupt climate change originates in the tropical regions is yet to be carefully explored. A pressing contemporary concern is that human-induced increases in atmospheric CO2 and the warming predicted for the 21st century have the potential to intensify the impacts of this natural variability. Hence it is crucial that we understand the mechanisms behind these rapid shifts in climate.

Project description:

This project will address land-sea correlations in the American tropics by combining oceanic and terrestrial tracers from marine sedimentary sequences. High-resolution data of vegetation-based atmospheric change and sea surface temperature (SST) changes will be produced from two marine sequences from the Integrated Ocean Drilling Program (IODP). Climate reconstructions over land will be based on fossil-pollen records of vegetation dynamics and SST will be reconstructed using Uk37 at the NERC LSMSF Facility in Bristol. The project will concentrate on quantifying the tropical climatic signature of two past abrupt climate fluctuations between 18,000 and 12,000 years ago: Heinrich stadial 1 and Greenland Interstadial 1. Phase relationships between oceanic and land changes will be constrained using up-to-date statistical techniques. The project will take advantage of two sedimentary sequences strategically located under the influence of three major atmospheric systems in the American tropics: the Inter-tropical convergence zone, the North American Monsoon and the South American Summer Monsoon. This approach is ideal to address questions around the forcing and timing of abrupt climate events in the American tropics because it will produce integrated multi-tracer data based on direct comparisons between marine and atmospheric markers from the same sequence. Results from this project will therefore allow constraining the chronology for the regional expression of HS1 and GI1 in the American tropics.

The closing date for applications is midnight on 6 January 2017.

Please see http://www.exeter.ac.uk/studying/funding/award/?id=2291 for full details on how to apply.