About the project
The solar atmosphere is filled with magnetohydrodynamic (MHD) waves. As the MHD waves carry magnetic energy, they have an important role in transporting energy across different layers of the solar atmosphere and in dissipating said energy. MHD waves are commonly observed in coronal structures such as coronal loops, coronal rain and prominences which act as waveguides. Waves also act as a tracer of energetic events occurring in the corona as a result of magnetic reconnection. The diagnostic properties of such waves can be exploited using a technique known as coronal seismology.
Objectives
The primary goal of the ORCS project is to combine the self-consistent numerical simulations of the solar atmosphere and high-resolution solar observations to understand the generation, evolution and dissipation of MHD oscillations in the structured and dynamical solar atmosphere. With the Bifrost code we can model a portion of the solar atmosphere spanning from the convection zone all the way into the corona. The evolution of the coronal magnetic field in such simulations is self-consistently driven by the dynamics of the lower solar atmosphere. This means that Bifrost simulations are capable of capturing realistic coronal dynamics, and can therefore be used as a laboratory for studying oscillations in the corona.
Coronal oscillations in Bifrost models
We have recently shown that coronal oscillations are common in Bifrost simulations (Kohutova & Popovas 2021). We used the forward-modelled EUV emission and three-dimensional tracing of the magnetic field to analyse oscillatory behaviour of individual magnetic loops. This work has shown that the oscillation characteristics and oscillation modes present in Bifrost simulations are similar to those observed in the Sun.
Bifrost models also provide insights into mechanisms for damping and dissipation of coronal oscillations. These are apparent in the characteristics of the heating due to the dissipation of coronal oscillations, which is periodic, as opposed to impulsive and sporadic heating driven by the magnetic braiding and reconnection. ORCS aims to investigate how well analytical models for damping and dissipation of oscillations translate into realistic magnetic field geometries.
Link to solar observations
The signatures of the oscillation excitation and dissipation mechanisms inferred from the simulations will be compared to high-resolution observations of coronal oscillations using both well-established and new instruments. This will involve submitting a proposal for observing time by the Daniel K. Inouye Solar Telescope, which has started science observations in late 2021. A postdoctoral researcher will join ORCS in 2022 to focus on the observational aspects of the project.
Project period
2021-2025
Financing
The ORCS project is funded by the Research Council of Norway.