The two leading theories on the coronal heating problem are on the dissipation of magnetohydrodynamic (MHD) waves, and the myriad of nanoflare-sized bursts on the order of 1024 erg from small-scale magnetic reconnection events driven by the braiding. It is unclear how much heating is contributed by MHD waves and reconnection, and a direct observational signature to coronal reconnection could not be established until the discovery of nanojets by Antolin et al. (2021). Nanojets represents component magnetic reconnection in a braided field, thus clearly identifying the reconnection-driven nanoflares from similar intensity bursts produced by other mechanisms. However, due to their small-scales (< 1500 km in length, < 500 km in width) and short timescales (< 25 s), its ubiquity is unknown and its driving mechanism is still an open question. In this thesis, we present a variety of IRIS and AIA observations of nanojets in different structures including loops and a flare. The variety of structures and environments support nanojets being a general result of component reconnection that can also be driven by dynamic instabilities. We have also observed low-amplitude transverse MHD waves in a coronal loop that directly result from braiding-induced reconnection (identified by the presence of nanojets), providing major support to existing theories that transverse MHD waves can be a signature of reconnection. Additionally, the effects of MHD waves on nanojet generation mechanism is investigated through 3D MHD simulations using the PLUTO code, which shows the role of waves in triggering the reconnection event by increasing the current density and producing similar characteristics to the nanojets.
- The Sun
- Solar Physics
- Solar Corona
- Magnetohydrodynamics
Deciphering the nanojet phenomenon in the solar atmosphere through observations and numerical simulations
Sukarmadji, R. (Author). 3 Sept 2024
Student thesis: Doctoral Thesis