PhD: Mechanisms for shelf sea carbon uptake

Project Description

The problem :

The highly productive shelf seas act as net sinks for the greenhouse gas carbon dioxide (CO2) [Bakker et al., 2013]. Two complementary mechanisms have been proposed for the shelf sea carbon pump. Both mechanisms require off-shelf transport of CO2-enriched water. The original shelf sea carbon pump concept [Tsunogai et al. 1999] suggests more wintertime cooling on the shelf than in the neighbouring ocean. This increases the solubility for CO2 and creates a shelf sea carbon sink. The second pump mechanism relies on seasonal stratification and photosynthesis creating a summertime CO2 sink, downward transport of organic matter and CO2-enrichment of the bottom layer by remineralisation [Thomas et al. 2004].

Surface Ocean CO2 Atlas synthesis products [Pfeil et al. 2013] provide unprecedented access to surface water CO2 data for the coastal seas. Data density is particularly high for the 2000s along shipping routes frequented by Voluntary Observing Ships with CO2 instrumentation. Various mapping techniques have been used for the quantification of oceanic CO2 uptake.


The research :

This PhD project will provide an understanding of the processes driving the spatial and temporal (seasonal, year-to-year and longer-term) variation of shelf sea carbon uptake for North-western European shelf seas. First the student will quantify CO2 air-sea fluxes, while using SOCAT and adopting a mapping technique to the shelf sea environment. Processes of interest include mixing, warming and cooling, biological activity, river inputs, advection, off-shelf transport, and regional climate variation. Water column biogeochemical data, satellite observations and modelling may be used for gaining a better process understanding. The student will participate in international SOCAT activities.



Bakker D.C.E., and 10 co-authors: Air-sea interactions of natural long-lived greenhouse gases (CO2, N2O, CH4) in a changing climate. In: Liss, P.S., Johnson, M. et al. (eds.) Ocean-atmosphere: Interactions of gas and particles. Springer Verlag. In press, 2013.

Pfeil, B., Olsen, A., Bakker, D. C. E., and 68 co-authors: A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT), Earth Syst. Sci. Data, 5, 125-143. doi:10.5194/essd-5-125-2013, 2013.

Thomas, H., Bozec Y., Elkalay, K., De Baar, H. J. W.: Enhanced open ocean storage of CO2 from shelf sea pumping. Science 304(5673): 1005-1008. doi:10.1126/science.1095491, 2004.

Tsunogai, S., Watanabe, S., Sato, T.: Is there a "continental shelf pump" for the absorption of atmospheric CO2? Tellus 51B(3): 701-712. doi:10.1034/j.1600-0889.1999.t01-2-00010.x, 1999.


Start date: Oct 2015

Programme: PhD

Mode of Study: Full Time


How to Apply

Deadline: 31 May 2015. NB Applications are processed as soon as they are received, so early application is encouraged as the project may be filled before the application deadline.


More information and apply online.