My research is concerned with the Sun’s mysterious atmosphere known as the corona. It is hundreds of times hotter than the Sun’s surface. Events in the corona may affect the Earth and the technologies we depend upon such as satellites, radio transmissions, and electricity grids
Working with departmental colleague Dr Huw Morgan, I have been analysing global conditions in the solar corona to provide an estimate of the relative contributions of the quiet corona and active regions to the Sun’s extreme ultraviolet (EUV) irradiance between 2010-2017. In contrast to the quiet corona, active regions usually lie above sunspots and contain strong magnetic fields.
An important conclusion of our study is that the EUV irradiance received at Earth cannot be accurately predicted from simple indices of solar activity such as sunspot area. Other factors such as the quiet coronal component or the long-term variations in active region temperatures must also be taken into account.
This image of the sun shows the changing appearance of the corona from solar minimum in May 2010 (left) to solar maximum in December 2014 (right) when large numbers of sunspots are present. It can be seen that the area covered by active regions increases towards solar maximum.