How does the Sun convert its mechanical energy reservoir into heat?


The Sun has always been a unique source for our understanding of the Universe in its many forms. It provides a working example where both magnetic and non-magnetic structures can be studied over an enormous range of spatial (100 km – 100,000 km) and temporal (subsecond to months) scales. While we are only able to catch glimpses of these processes and phenomena in other astrophysical sources, the Sun provides a vantage reference point where the complex interplay between the plasma and the magnetic field is visible and can be studied continuously with unprecedented detail. The temperature in the Sun’s outer atmosphere rises rapidly from a few thousand degrees in the photosphere to over one million in the corona. Understanding how the Sun manages to achieve this feat requires an accurate evaluation of the magnetic field annihilation processes and the conversion of magnetic energy into heat.

Project Description

The brightness and spectrum of the solar atmosphere are two very common properties used in most research studies. However, there exist a third property: polarisation. Polarisation is as important as brightness and an essential property of light that can be used as a diagnostic for the magnetic field. Dedicated instruments have been constructed that measure the Stokes profiles of spectral lines 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.

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

  • Determine the polarimetric properties of small-scale magnetic field cancellations in the solar photosphere and chromosphere
  • Use inversion techniques to evaluate the magnetic field strength and inclination
  • Compare the magnetic energy with the radiative and kinetic energy losses
  • Carry out new observations that push the limits of detectability of current instrument
  • Use the observations and simulations to define the science goals of future ground-based and space-borne observatories. These observatories include the Daniel K Inoue Solar Telescope and the European Solar telescope.

Other information

The student will work in collaboration with an international team of researchers at QUB, Europe and the US. For more information please see the project supervisor.

Facilities to be used

NICOLE+RH (Inversion algorithms), Swedish Solar Telescope (La Palma), Dunn Solar Telescope (New Mexico), Daniel K Inoue Solar Telescope (Maui), GREGOR Telescope (Tenerife)

QUB staff and students associated with the project

Prof M. Mathioudakis, Dr Dave Jess, Dr Aaron Reid, Dr Peter Keys

More information from the primary supervisor: Prof Mihalis Mathioudakis

public/phds2017/2017_mathioudakis_pol.txt · Last modified: 2016/12/09 22:33 by Stuart Sim

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