Dynamics in solar prominences - connecting from small to large scale

Recent space based solar missions, the Japanese Hinode mission and the NASA Solar Dynamics Observatory (SDO) mission, have provided breathtaking observations of quiescent prominences (cool - 8000K - clouds of partially ionised plasma floating in the 1MK solar corona) revealing them to be highly dynamic phenomena where the fundamental process of a magnetised plasma are on constant display. To provide a specific example, one of the most exciting discoveries is that of the magnetic Rayleigh-Taylor instability, an instability that grows when a dense fluid is above a light fluid and the boundary is perturbed resulting in the formation of rising and falling plumes. Due to the fundamental physics that drive these dynamics, the answers of many of the key questions relating to prominences - i.e. what determines when they erupt, how do instabilities grow in the complex prominence environment, how does magnetic reconnection (the change in connectivity of a magnetic field that releases energy) work in the partially ionised prominence plasma, what are the connections between the different scales in prominences - are likely to be hidden within them. However, the great complexity if the prominence system has meant that we are still to understand these beautiful structures known as prominences.

Recent advances in computational power, theoretical modelling and the launch of the new NASA satellite the Interface Region Imaging Spectrograph (IRIS) - with its high sensitivity and resolution - mean that we now have the tools to tackle the problems relating to this complex system. Using a state-of-the-art code which simultaneously solves the dynamics of the neutrals and the ions in a partially ionised plasma system the interaction between the two fluids that make up the prominence plasma can be correctly tracked. Simulations of the fundamental physics that control the prominence system will be performed with this partially ionised plasma code, with the results compared and contrasted to the observational data to let theory and observations guide each other. Through this feedback approach employing all the tools that are available to use, we can head towards a new and exciting understanding to the prominence system.

The proposed work has a number of key aims that will be investigated:
1) How do MHD instabilities (in particular the magnetic Rayleigh-Taylor instability) form in quiescent prominences.
2) How does the presence of instabilities on small spatial and temporal scales effect the prominence system on longer timescales and larger spatial scales, what are the observational signatures of these processes and how do they relate to prominence eruptions.
3) What are the basic physics that controls the reconnection of magnetic fields in the partially ionised prominence material across the many observable scales.
4) How can we connect between the dynamic phenomena observed and the complex physics of the prominence system. This research would take place at the Department of Applied

Mathematics and Theoretical Physics (DAMTP), University of Cambridge. In this project, I will investigate the wide range of observed prominence dynamics from both a theoretical and observational perspective. Therefore, the use of a wide range of techniques, from large-scale numerical simulations of the formation of instabilities in a prominence to the analysis of the spectral lines emitted by solar plasma to determine the plasma motion in the prominence, will be necessary. The senior staff at DAMTP have great experience in a wide range of areas required for my study. Drs. Helen Mason and G. Del Zanna are world leaders in the field of solar spectral observations and Profs. M. Proctor, J. Papaloizou and G. Ogilvie are greatly experienced in the study of astrophysical systems through large-scale numerical simulations. All these combine to make DAMTP the perfect place to be to get the full support necessary for my work.