Pushing the Boundaries: Solar Physics in an Era of High Spatial and Temporal Resolution

The Sun is the most important astronomical object for humankind, with solar activity driving 'space weather' and having a profound effect on the environment and communications. Here on Earth, we can see directly the effects of the Sun's radiation through fascinating sights such as the aurora. However, currently the power behind the Sun's activity cannot be predicted, or indeed fully explained. Most would expect that as you move away from a fierce heat source, such as a naked flame, the temperature will drop significantly. However, one of the greatest paradoxes plaguing solar-system scientists is the fact that the outer atmosphere of the Sun is much hotter than its surface! An increase in temperature from around 6000 degrees to well over one million degrees as you travel away from the surface belies common sense and has remained at the forefront of solar-system research for over 50 years. Many theories have been proposed in an attempt to understand the inner workings of this complex dynamical system, producing two distinct classes of theory: flare events and wave heating. The former suggests that rapidly occurring, small explosive events in the atmosphere of the Sun may cause the observed steep temperature gradient. The latter relies on the generation of magneto-hydrodynamic (MHD) waves which propagate upwards from the surface of the Sun and dissipate in the corona. A good analogy is to imagine ocean waves travelling across the vast seas before finally releasing their energy when they splash up against a rocky coastline. Theory suggests that MHD waves generated near the surface of the Sun through the continual churning of plasma may propagate upwards if the conditions are correct, ultimately dissipating their energy and heating the outer solar atmosphere. As an STFC Postdoctoral Fellow at QUB, I will utilize modern ground- and space-based telescopes containing a wide assortment of high resolution instruments. The observational component of my research programme will focus on the distinction of individual MHD waves, which will allow key characteristics to be evaluated. These include the mode of oscillation (longitudinal, transverse, etc.), the velocity, the direction and of course, the energy. I will compare these values to those specific for atmospheric heating of the Sun, thus allowing the current theoretical heating models described above to be validated or refuted. Computer simulations will also be implemented to validate observational methodologies and accuracy, culminating in much refined models of the solar atmosphere. With the rapid advancements made in the field of solar physics over the last number of years (better telescopes, detectors and computers), the ability to finally resolve the atmospheric heating paradox is now a reality and that is what I will strive to do as an STFC Postdoctoral Fellow.