PLEASE NOTE: Application deadline date 08 Jan 2024. Applications are no longer being accepted for this project
Project Overview
Dissolved organic carbon (DOC) is the largest pool of reduced carbon in the ocean, sequestering 2 Pg C/yr of atmospheric carbon dioxide. This project uses in situ physical and chemical observations to investigate how overturning processes in the Nordic Seas inject vast amounts of DOC into the deep ocean.
Project Description
At 2 petagrams of carbon per year, the downward export of dissolved organic carbon (DOC) from the ocean surface represents a large fraction (>15%) of the total carbon sequestration by the biological carbon pump. The Atlantic Meridional Overturning Circulation (AMOC) introduces most of this DOC to the deep ocean. This important carbon sink may be critically endangered if model predictions of future decline of the AMOC are correct. Recent research has shown that small-scale processes near the East Greenland margin could be responsible for most of the DOC sequestration, yet those processes, their evolution under climate change, and the origin and fate of the exported DOC are poorly understood. In this project, you will use observations collected from two (summer and winter) cruises across the East Greenland Current (EGC) of the Nordic Seas to shed light on this problem. You will analyse observations of Dissolved Organic Matter (DOM) concentration, optical properties, and isotopic and molecular composition, together with ocean chemical and physical observations to answer the following questions:
(1) what is the origin of the DOC in the deep waters of the EGC?
(2) what physical processes are responsible for DOC export?
(3) what is the DOC chemical composition and how does this influence the long-term carbon
sequestration potential?
Depending on your skills and interests, you could also use ocean models to fully unravel the three-dimensional processes underpinning DOC export and the long-term carbon sequestration potential, and how these processes will evolve in the future.
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at Ocean and Earth Science. Specific training will
include:
- Opportunities to take part in fieldwork
- Training chemical, optical and isotopic characterisation of organic matter
- Training in data analysis, visualisation and interpretation with programming languages
- Understanding of the physical processes in the ocean relevant to global overturning circulation
- Training in use and analysis of ocean model data
- Opportunities to visit project partners, experts in physical oceanography and ocean biogeochemistry, in Norway, Spain and the US
- Opportunities to attend national/international conferences to present the candidate’s results and broaden their scientific network.
Hansell, D.A., C.A. Carlson, D.J. Repeta, and R. Schlitzer. 2009. Dissolved organic matter in the ocean: A controversy stimulates new insights. Oceanography 22(4):202–211, https://doi.org/10.5670/oceanog.2009.109.
Fernández-Castro, B., Álvarez, M.,Nieto-Cid, M., Zunino, P., Mercier, H.,& Alvarez-Salgado, X. A. (2019). Dissolved organic nitrogen production and export by meridional overturning in the eastern sub-polar North Atlantic. Geophysical Research Letters,46, 3832–3842.https://doi.org/10.1029/2018GL080284
Våge, K., Papritz, L., Håvik, L. et al. Ocean convection linked to the recent ice edge retreat along east Greenland. Nat Commun 9, 1287 (2018). https://doi.org/10.1038/s41467-018-03468-6
