The magnetic and thermodynamic properties of small-scale solar magnetic structures

Background

Magnetic flux emerges from the convection zone to the solar surface over an enormous range of spatial (100 km – 100,000 km) and temporal (seconds to months) scales. The turbulent nature of convection generates a continuous magnetic energy spectrum spanning over many orders of magnitude. The vast majority of magnetic flux detected on the solar surface is linked to global dynamo processes and the solar cycle. The presence of a non-zero local flux can indicate the existence of a local, surface dynamo that is independent of the solar cycle and plays a key role to the emergence, coalescence, fragmentation and cancellation of magnetic elements. The evolution and dynamics of these small-scale structures contributes to the energy balance of the solar atmosphere. It is believed that the small energy releases that arise from these structures, can hold the answer to how the temperature in the Sun’s outer atmosphere rises rapidly from a few thousand degrees in the surface to over one million degrees in the corona.  

Project Description

The project will study the physical properties of small-scale magnetic elements in the lower solar atmosphere and quantify the processes at work. It will consider the brightness, spectrum and polarisation of light in selected spectral lines and continuum. It will use dedicated instruments have been constructed to measure the Stokes profiles with high polarimetric accuracy and sensitivity. State-of-the-art inversion techniques have been developed alongside the instruments to extract physical information from spectropolarimetric observations. We anticipate that the project will use observations from the 4m Daniel K Inouye Solar Telescope, the largest solar telescope in the world, where QUB has a leading role.

The main aims of the project can be summarized as follows:

• Acquire imaging spectropolarimetric datasets

• Determine the degree of polarization of small-scale structures in the solar photosphere
• Use inversion techniques to evaluate the properties of the magnetic and thermodynamic properties of the plasma
• Compare the magnetic energy with the radiative and kinetic energy losses
• Assist with the development of detector technology that push the limits of detectability of current instruments 

Other information

• The student will work in collaboration with researchers at QUB, and other research institutes worldwide

Facilities to be used

• DESIRE, HAZEL, SIR (Inversion algorithms), Swedish Solar Telescope (La Palma), Daniel K Inouye Solar Telescope (Maui), GREGOR Telescope (Tenerife)

More information from: Prof Mihalis Mathioudakis and/or Dr Ryan Campbell