PhD Research Project: NERC CENTA - Deciphering carbon and climate system interactions across abrupt

Location
United Kingdom
Posted
Nov 30, 2016
Closes
Jan 23, 2017
Organization Type
University and College
Hours
Full Time
Details

The Eocene epoch (34-56 million years ago; Ma) was characterised by warmer global temperatures and higher atmospheric carbon dioxide levels than today and small or no ice-sheets. These high-CO2 worlds were traditionally considered to be relatively climatically stable but we now know that they were punctuated by numerous transient global warming or ‘hyperthermal’ events[1] that are perhaps our best analogues for anthropogenic change.

One such warming event was the Middle Eocene Climatic Optimum (MECO) which reversed a long-term global cooling trend, ~40 (Ma)[2]. During the MECO global ocean temperatures rose by ~3-5 °C, surface ocean nutrient levels increased, the carbonate compensation depth shoaled by >1 km in all ocean basins, and there were large shifts in both floral and faunal communities[2,3].

However, our inability to reconcile observations with basic carbon cycle theory across the MECO highlights major gaps in our understanding of the link between the climate and carbon cycle over intermediate timescales (~50-500 kyrs)[4]. This is exacerbated by a dearth of records against which to test key hypotheses. For instance, we still have very poor constraints on the rate and timing of carbon input, the magnitude of tropical and high northern latitude temperature change and the driver(s) of the environmental change (e.g., volcanism vs. ocean circulation changes)[4]. This project will fill these critical gaps in our understanding of the global climate system during past high-CO2 intervals and ultimately help to reduce uncertainty related to predicting future climatic changes.

This project will generate new high-temporal resolution records of global climate and carbon cycling across the MECO event at multiple International Ocean Discovery Program (IODP) sites. This may also include new highly expanded Eocene sediment sequences recently recovered by IODP Exp. 342 off the Newfoundland margin that offer the opportunity to reconstruct the event at unprecedented temporal resolution. This PhD project will involve detailed taxonomic, and geochemical (13C and 18O, trace element ratios) study of foraminiferal tests preserved in deep-sea sediments spanning the MECO to constrain a range of environmental parameters including; temperature, ice volume, and carbonate chemistry. These data will be supplemented with faunal and sediment analyses, e.g., scanning election microscopy to determine test preservation, and fragmentation and %CaCO3 records to constrain deep ocean chemistry.

Funding Notes

In addition to completing an online application form, you will also need to complete and submit the CENTA studentship application form available from www.centa.org.uk.

CENTA studentships are for 3.5 years and are funded by the Natural Environment Research Council (NERC). In addition to the full payment of their tuition fees, successful candidates will receive the following financial support.

Annual stipend, set at £14,296 for 2016/17
Research training support grant (RTSG) of £8,000

CENTA students are required to undertake from 45 days training throughout their PhD including a 10 day placement.

References

[1] Sexton et al., Nature, 471, 349-352 (2011).
[2]Bohaty et al., Paleoceanography, 24, doi:10.1029/2008PA001676 (2009).
[3] Edgar et al., Palaeogeography, Palaeoclimatology, Palaeoecology, 297, 670-682 (2010).
[4] Sluijs et al., Nature Geoscience, 6, 429-433 (2013).