PhD: Mapping deep ocean mixing using autonomous gliders: Atlantic, Indian, and Southern Oceans

Project Description

Scientific Rationale

The ocean is a turbulent place. Eddies of all scales, from 100s of kilometres to millimetres, stir the ocean and in the process mix waters with different physical and chemical properties together. We know the kinetic energy driving these eddies and turbulent mixing comes from one of two sources, either the wind or the tide. We also know roughly how much energy each of these sources provides, 1 terawatt from the wind (that’s about 2 billion blenders) and 3.5 terawatts from the tide. What we don’t fully understand is how this energy travels through the ocean’s interior and where in the global ocean the resulting mixing takes place. This uncertainty limits our understanding of deep ocean circulation and the capability of climate models.

 

Research Methodology

During this project you will use data from autonomous underwater gliders to identify areas of the global ocean where turbulent mixing is energetic and also investigate the causes and biogeochemical implications of this mixing. You will be involved with the deployment and piloting of gliders in an upcoming observational campaign, then use a variety of methods to diagnose mixing processes in both this dataset and archive glider data. Once areas of energetic mixing have been identified you will investigate the dynamical processes that cause the mixing (e.g., internal waves) and also its effect on local ocean chemistry and phytoplankton populations. Knowledge gained during this project may be used to improve the representation of these processes in ocean circulation and climate models.

 

Advanced Training

You will participate in a research cruise to either the North Atlantic or Indian Ocean where you will gain experience in practical oceanographic methods. You will also join the UEA glider group (www.ueaglider.uea.ac.uk) and be trained in glider deployment, piloting, and advanced data processing and analysis methods.

 

Personal Specification

The ideal candidate will have a good physical science degree or similar (e.g., oceanography, meteorology, physics, environmental sciences, natural sciences, engineering, mathematics). Experience of computer programming (e.g., Matlab, Fortran) is an advantage. Training in physical oceanography will be provided so a background in ocean science is not required.

 

References

Beaird, N., I. Fer, P. Rhines, and C. Eriksen, 2012: Dissipation of turbulent kinetic energy inferred from Seagliders: An application to the eastern Nordic Seas overflows. Journal of Physical Oceanography, 42, 2268–2282, doi:10.1175/JPO–D–12–094.1.

Fer, I., A. K. Peterson, and J. E. Ullgren, 2014: Microstructure measurements from an underwater glider in the turbulent Faroe Bank Channel overflow. Journal of Atmospheric and Oceanic Technology, 31, 1128–1150, doi:10.1175/JTECH–D–13–00221.1.

Rudnick, D. L., T. M. S. Johnston, and J. T. Sherman, 2013: High-frequency internal waves near the Luzion Strait observed by underwater gliders. Journal of Geophysical Research, 118, 1–11, doi:10.1002/jgrc.20083.

Thorpe, S. A., 1977: Turbulence and mixing in a Scottish loch. Philosophical Transactions of the Royal Society of London, Series A, 286, 125–181.

 

Information

Start date: October 2015

Programme: PhD

Mode of Study: Full Time

 

More information and apply online.