I am currently a final-year PhD student in atmospheric dynamics supervised by Dr. Hua Lu (BAS) and Prof. Nick Mitchell (University Of Bath). Prior to starting my PhD in October 2012, I completed my BSc (Hons) undergraduate in Mathematics at the University of York. During my undergraduate studies, I took particular interest in the fluid dynamics which govern the circulation of both the Atmosphere and the Oceans, culminating in my writing of a dissertation on the ‘Quasi-Geostrophic Wave Dynamics in the Rotating Shallow Water Model’.  

In my spare time I like to play a variety of sports. I play badminton for a local club and like to turn my hand to tennis and table tennis too. Outside of racquet sports, I enjoy swimming and hiking and love watching films and tv shows!

Research interests

My PhD topic focusses on the region known as the stratosphere, between approximately 10km and 50km in height. The Northern-hemisphere winter stratosphere is home to two large jets; the tropical quasi-biennial oscillation (QBO) – an oscillation of westerly and easterly winds on a near 2-year cycle – and the high latitude Polar Vortex – the strong westerly winds which circumnavigate the Polar Regions. These two jets interact via a teleconnection between the tropics and high latitudes. In particular, when the QBO is in its easterly phase, the Polar Vortex is significantly weaker and thus warmer, whereas when the QBO is in its westerly phase, the Polar Vortex is stronger and hence colder. This teleconnection has been coined the ‘Holton-Tan Effect’ (HTE) after its initial discovery by Holton and Tan (1980). In the years since its first discovery it has been robustly observed and recreated in models. Many mechanisms have been suggested to explain the HTE, all relating to the changes in large-scale planetary waves (also known as Rossby waves) under each QBO phase. However, there is no consensus as to which mechanism(s) hold and the aim of my PhD has been to shed further light on the matter using a different approach.

We have been using a framework in spherical, isentropic (i.e., potential-temperature) coordinates rather than the more traditionally used pressure coordinates. On such isentropic levels, a dynamical-thermodynamical quantity known as potential vorticity (PV) is conserved in the absence of dissipative effects. Rossby waves are intrinsically linked to this quantity and thus such a framework is particularly apt for our study. Our primary focus is to quantify the changes in Rossby-wave propagation, the mean flow (i.e., wind) and their concurrent wave-mean-flow interactions under each QBO phase.

In addition to the more specific PhD topic, I have broader interests in understanding:

• The general circulation of the atmosphere;
• Jet dynamics related to the tropospheric subtropical and eddy-driven jets;
• Extratropical eddy-mean-flow interactions in the both the stratosphere and the troposphere;
• Eddy-eddy interactions between different waves in the wave spectrum;
• Critical layer dynamics;
• Barotropic and baroclinic instability.

Publications from NERC Open Research Archive

1. FEATURED PAPER: Polar Vortex teleconnection

   This paper provides new evidence and proposes a new dynamical mechanism for the teleconnection between the two largest jet streams in the northern winter stratosphere – the tropical wind system […]

   Read more of: FEATURED PAPER: Polar Vortex teleconnection