skip to primary navigationskip to content
 

C307: Whipping up a storm – reconstructing winds using Antarctic ice cores (Lead Supervisor: Liz Thomas, British Antarctic Survey)

Supervisors: Liz Thomas (British Antarctic Survey), Claire Allen (British Antarctic Survey) and Eric Wolff (Earth Sciences)

Importance of the area of research:

Reconstruction of the regional palaeo-atmospheric circulation in Antarctica is imperative in understanding the past and future responses of Antarctic continental ice to our changing climate. Surface wind drives upwelling of Circumpolar Deep Water and forces intrusions of warm water onto the continental shelves, which in turn accelerates the basal melting of the associated ice-shelves [i]. This is a strong driver of melting the West Antarctic Ice Sheet, of which the IPCC has determined is one of the most important unknowns in forecasting the future of sea level rise.

Diatoms entrained in ice cores have emerged as a novel proxy for regional wind strength and local atmospheric circulation. Developing this proxy, together with a suite of palaeoclimate records from both ice cores and marine records, will enable us to reconstruct past wind strength across the southern ocean and assess its relationship with Antarctic climate and surface mass balance.

Project summary:

Long distance aeolian proxies such as dust have been used to reconstruct past atmospheric circulation over glacial timescales [ii], however there is little to help us reconstruct regional wind patterns and their temporal and spatial variation. A study by Thomas et al. [iii] has revealed the exciting potential to use diatoms as a proxy for onshore winds in the Amundsen-Bellingshausen Seas since 1700AD. Extending the record both regionally and temporally (through the Holocene and deglaciation) will unlock the full potential that diatoms have in understanding how regional wind patterns have changed, and are likely to change in future.

What the student will do:

The student will investigate the diatom abundance, species assemblages and total particulate content on a variety of Antarctic ice cores to determine their spatial and temporal variation. Unknown factors such as decay with distance inland and altitude will be explored, as will new methods and analytical techniques of quantifying diatoms which will expand the proxy’s value on both continental and temporal scales. The student will analyse an array of Antarctic ice cores to reconstruct past wind strength and atmospheric circulation over the southern ocean and Antarctica over centennial to millennial timescales.

Please contact the lead supervisor directly for further information relating to what the successful applicant will be expected to do, training to be provided, and any specific educational background requirements.

 References:

[i]  Pritchard, H. D., S. R. M. Ligtenberg, H. A. Fricker, D. Vaughan, M. R. van den Broeke, and L. Padman. 2012. Antarctic ice-sheet loss driven by basal melting of ice shelves, Nature, 484(7395), 502-505.

[ii]  Fischer, H., M.-L. Siggaard-Andersen, U. Ruth, R. Rthlisberger and E.Wolff. 2007. Glacial/interglacial changes in mineral dust and sea-salt records in polar ice cores: sources, transport, and deposition, Reviews of Geo-physics 45, doi:10.1029/2005RG000192.

[iii] Reconstructing wind strength and atmospheric circulation in West Antarctica over the past 300 years, PI Dr E R Thomas [NE/J020710/1]

Follow this link to find out about applying for this project.

Filed under: