On the dynamics of spicules and mass flows in the solar atmosphere

Abstract

The atmosphere of the Sun is envisioned as composed of inherently complex, non-homogeneous, and dynamic layers. A detailed understanding of the physical processes involved in these layers is still lacking. For example, it is largely unknown why the outermost layer of the Sun’s atmosphere (corona) is so much hotter than the photosphere by millions of degrees. Astrophysicists think that the layer sandwiched between the photosphere and the corona, known as the interface region, may hold the key to a better understanding of the nature of this controversy. With the help of coordinated high-resolution ground and space-based observations from the Swedish 1-m Solar Telescope (SST) on La Palma, Spain, and NASA’s Interface Region Imaging Spectrograph (IRIS), I aim to unlock some of the mysteries surrounding the dynamics of the interface region with a focus on small-scale jets, known as “spicules”. Spicules are found almost everywhere on the Sun’s surface and at any given moment there can be as many as 10 million of them rapidly shooting outwards. Because of their “omnipresence”, it is suggested that they play a major role in energizing the outer atmospheric layers of the Sun. This thesis focuses on their physical characteristics, dynamics, and their role in the mass-balance and heating of the solar atmosphere.