Paul Pružina


I am a PGR based in the School of Mathematics at the University of Leeds working with Prof David Hughes and Dr Sam Pegler, investigating the formation of density staircases in stratified fluids. I previously completed my Masters in Mathematics at the University of Cambridge, including a project on the Madden-Julian Oscillation. I balance my PhD work with training and competing in orienteering and fellrunning races, and playing the piano in my spare time.


2018 – 2019: MMath, University of Cambridge

2015 – 2018: BA Mathematics, University of Cambridge

Research Interest

Geophysical fluid dynamics, physical oceanography, stratified flows, turbulence modelling.

Teaching interests

I am involved with teaching and marking in various undergraduate Applied Maths modules.

Project Title

Staircase Formation in Fluid Dynamical Systems


Professor David Hughes

Dr Sam Pegler


Panorama NERC DTP, 2019

Project outline

Many fluid dynamical systems show staircase-like profiles in a scalar quantity (e.g. density), with well-mixed layers separated by sharp interfaces. Key examples include thermohaline staircases resulting from double diffusive convection, potential vorticity staircases in planetary atmospheres, and ExB staircases in plasma physics.

The current focus of the project is on producing a reduced model for double diffusive staircases, which can be used to better understand their dynamics, and make predictions about their behaviour, including the long-term stability, and layer-merging events. The heat flux through staircases is significantly higher than in non-layered regions, so an accurate model of heat flux has the potential to contribute to the ocean-atmosphere heat flux in climate models.

With a good understanding of DDC staircases, the aim is then to draw together different physical systems to look for common features of staircases, and produce a more general model that is applicable to multiple areas.