Seismic studies of the Sun's magnetic activity

The main aim of the project is to use helioseismic oscillation to characterize magnetic activity in the Sun. Helioseismology uses the Sun's natural resonant oscillations to profile the solar interior. These oscillations are sensitive to the presence of magnetic fields: Their frequencies, amplitudes and damping times all vary through the solar cycle. We will use Empirical Mode Decomposition techniques to study the solar cycle variations in helioseismic mode parameters. By doing this we will not only be able to characterize the 11yr solar cycle but also the long-term variations, such as the quasi-biennial cycle. We will use resolved helioseismic observations, such as those made by GONG, MDI, and HMI. We will then combine with the modelling techniques, detailed in Kiefer et al (2017), to characterize how the Sun's internal magnetic field varies over the 11yr and quasi-biennial cycle. This information can then feed into dynamo models of the Sun.