Mr Thomas Joseph Crawford

Career

• 2012-present: PhD in Applied Mathematics, University of Cambridge
• 2008-2012: Mmath in Mathematics, University of Oxford

Research

Thomas is a member of the Department of Applied Mathematics and Theoretical Physics Geophysical Fluid Dynmaics research group. His current research interest is the discharge of rivers into the North Sea.

The North Sea, which is typically of shallow continental shelves, stratifies in the summer due to solar heating. In the shallower regions where tidal flows are strong the heat input by the sun is mixed throughout the water column but in deeper parts with weaker tides there is insufficient energy to mix this heat and it accumulates in the upper part of the water column leading to stratification. The transitions between these regions are marked by sharp fronts that act as barriers to transport of heat and also biological matter and pollutants. This process is well understood since the solar radiation is essentially uniform in space.

Rivers such as the Rhine and Elbe also input buoyancy in the form of fresh water and in this case the inputs are very localized in space, leading to large horizontal inhomogeneities. The subsequent dispersion and mixing of this fresh water and the pollutants (particularly nitrogen) are poorly understood, but vital to the water quality of much of the North Sea. What is known is that buoyancy-driven flow, mixing and advection by the tides and the influence of the rotation of the Earth all play important roles in the ultimate destination and properties of this water.

Thomas is currently conducting laboratory experiments on a high-precision rotating turntable to study both the qualitative and quantitative features of the spread of buoyant water through a turbulent environment.  

Selected Publications