Nordita Astrophysics seminars

Magnetic Helicity and Flux Tube Dynamics in the Sun

by Dibyendu Nandi (Indian Institute of Science Education and Research, Kolkata)

Helicity is a topological parameter relevant in many systems ranging from the living world, to the physical world. Plausibly the most apparent manifestation of helicity is knottiness, which is observed in strings, to strands of DNA or in the swirl of fluids flows and cyclonic convection. Magnetic flux tubes also have helicity, which is a conserved quantity in ideal magnetohydrodynamic systems such as the solar plasma. Because of its invariance, specifically in line-tied closed flux systems, magnetic helicity can be a useful probe of flux tube dynamics in the Sun’s convection zone. Moreover, the helicity of magnetic flux systems may also play an important role in relaxation dynamics leading to solar eruptive activity and the heating of the solar corona. In this talk, based on observations of solar magnetic fields I will discuss the role of magnetic helicity in constraining flux tube dynamics in the convection zone and in driving solar energetic processes.