Relatively low thermal conductivity compared to that

relatively low thermal conductivity compared to that of the fluid, such as water on plastic, in the CR,
CA, SS and SJ modes of evaporation.
Magnetic Feature Detection through Coronal Volume Segmentation along Quasi-separatrix
Layers
Roger Scott - University of Dundee
David Pontin
Interchange reconnection is thought to play an important role in driving the dynamics of the slow
solar wind. In order to understand the details of this process, it is important to catalog the various
magnetic structures that are present at the open-closed flux boundary. To this end we have developed
a method for identifying discrete flux domains using watershed segmentation along quasi-separatrix
layers. In this way we are able to identify structures within the corona that affect the character of the
open-closed boundary. By analyzing an assortment of global field models we can then build up a
catalogue of common configurations and create a hierarchy for evaluating each one's relevance to the
process of interchange reconnection. This, in turn, informs our understanding of which configurations
should be given priority for upcoming numerical experiments, and how the results of these

experiments can be brought together to form a more complete picture of the global evolution of the
slow solar wind.
A Bifurcation Analysis of Spiral Waves using a FitzHugh-Nagumo Model
Shreya Sehgal - Liverpool Hope University
Andrew Foulkes
Spiral waves are spatio-temporal solutions to reaction-diffusion system of equations which have been
observed in a wide variety of biological, chemical and physical systems, both artificial and in nature.
There are several types of motion of spiral waves. In the simplest case, a free spiral rotates rigidly
while its tip describes a circular trajectory. It was also observed that under certain conditions a spiral
tip meanders rather than following a periodic circular orbit. Meandering is often not a random motion,
rather the spiral tip traces a path resembling an epicycloid, exhibiting flower-like patterns. It is a type
of quasiperiodic motion. It has been shown numerically by other authors that a supercritical Hopf
bifurcation is responsible for the transition from rigid rotation to meander. However, these studies
were limited to small core spirals.
In this project, we calculate the dynamics of the spiral wave in a co-moving frame of reference where
the core of the spiral never approaches the boundaries of the computation box and it allows the
computations of large core spirals using small numerical grids. This leads to a system of reaction-
diffusion-advection equations in which the tip of the spiral wave is fixed in position and orientation.
We conducted the bifurcation analysis of spiral waves by studying the underlying limit cycles of
meandering spiral waves using the FitzHugh-Nagumo system of equations. Results show that indeed a
Hopf bifurcation is responsible for the transition from rigid rotation to meander.