Name: Jessica Crumpton-Banks

Project Title: “Probing the processes linking primary productivity in polar oceans and atmospheric CO2Jess Crumpton-Banks photo

Cohort: 2015/16

Institution: University of St Andrews



I studied Environmental Geoscience (MSci) at the University of Bristol, graduating in 2015. My PhD project focuses on the role of the Southern Ocean in controlling atmospheric CO2 over recent glacial-interglacial cycles. Ice core records from Antarctica show us that Antarctic air temperature and atmospheric CO2 have been tightly coupled over the last 800,000 years, suggesting the Antarctic may play a dominant role in global climate cycles. The oceans are the largest store of carbon that can equilibrate with the atmosphere on the ice-core record timescales, and the Southern Ocean is considered a prime candidate because it is currently a “leak” of CO2 to the atmosphere. Currently old,  carbon-rich deep water upwells in the Southern Ocean and due to limited productivity, CO2 ougasses to the atmosphere. If this leak were somehow stemmed during glacial periods it could account for the glacial decrease in atmospheric CO2. The two current main hypotheses are either 1) increased sea ice cover or 2) enhanced surface stratification. Both would impose a physical barrier to carbon-rich waters upwelling to the surface, but each scenario would result in a different sea surface pH. Increased sea-ice cover would trap the acidic deep waters at the surface, resulting in a lower surface pH than in the case of enhanced surface stratification, where gas exchange can still occur at the air-sea interface. This project aims to reconstruct sea surface pH in the Southern Ocean using boron isotopes (a proxy for pH), contributing to our understanding of the role of the oceans on climate.
Publications/Conference talks/Posters:

Crumpton-Banks, J. G. M., Burke, A., Rae, J. W. B. and Greenop, R. (2015) Using boron isotopes to investigate Southern Ocean controls on glacial atmospheric CO2. Poster at PRiMES 2015, Cambridge. This poster won the “best poster” prize.

Crumpton-Banks, J. G. M., Greenop, R., Moore, K.A., Rae, J. W. B., Burke, A. (2016) Investigating the role of the Southern Ocean in glacial-interglacial CO2 changes using boron isotopes. Poster at GGRiP 2016, Leeds.

Crumpton-Banks, J. G. M. (2016) Investigating the role of the Southern Ocean in glacial- interglacial CO2 changes. Oral presentation at the Department of Earth and Environmental Sciences Postgraduate Student Conference 2016, St Andrews.

Crumpton-Banks, J. G. M., Rae, J. W. B., Greenop, R., Burke, A., Moore, K. A. & Nita, D. C. (2016) Glacial-interglacial CO2 in Southern Ocean surface waters. Poster at ICP 2016, Utrecht.
Get in touch:


Twitter: @jess_gmcb

Department webpage: