| Name: | Yogesh Kumar Maurya |
| Affiliation: | Udaipur Solar Observatory/Physical Research Laboratory |
| Conference ID : | ASI2024_610 |
| Title : | Generation and annihilation of 3D Magnetic Nulls in the Solar Atmosphere: Insights from MHD Simulation |
| Authors : | Yogesh Kumar Maurya 1,2, Ramit Bhattacharyya 1, David I Pontin 3 |
| Authors Affiliation: | 1 Yogesh Kumar Maurya, Ramit Bhattacharyya Affiliation (Udaipur Solar Observatory/Physical Research Laboratory, Udaipur-313001, India)
2 Yogesh Kumar Maurya Affiliation (Indian Institute of Technology Gandhinagar, Gandhinagar-382055,India)
3 David I Pontin Affiliation (The University of New Castle, Callaghan, NSW 2308, Australia) |
| Mode of Presentation: | Oral |
| Abstract Category : | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract : | Three dimensional (3D) magnetic nulls are the location where magnetic field is zero. They are preferential sites for magnetic reconnections and triggering various solar coronal transients. Although these nulls are abundant in the solar atmosphere, but their generation is yet to be thoroughly explored. In my previous work, Maurya et al. 2023 (doi:10.1063/5.0107601) have demonstrated magnetic reconnection to be the cause for generation and annihilation of magnetic nulls through magnetohydrodynamics simulation, where the initial magnetic field is idealized to have a single proper radial null. This work further extends the study in a more realistic scenario where the initial magnetic field is constructed by extrapolating photospheric magnetogram data and hence, incorporates field line complexities inherent to a complex active region. The simulation is initiated with non force free extrapolated magnetic field from photospheric vector magnetogram at around 02:48:00 UT on 17 February 2014 of an active region NOAA 11977 hosting a C6.6 class flare. The simulation starts from a motionless or with zero external flow and initially, only the non zero Lorentz force pushes the plasma to generate the dynamics. The simulation shows that the 3D magnetic nulls are spontaneously generated in pair having complementary topological degree and therefore, preserves the net topological degree. The simulation also shows 3D nulls annihilation in pair. Magnetic reconnections are identified to be responsible for the generation and annihilation of the nulls—opening up the possibility for the nulls to be self-organized structures. Furthermore, the reconnection being ubiquitous in the corona, it can explain the coronal abundance of magnetic nulls. |
