Karl Franzens University Graz

Graz University of Technology 

Magnetic Buoyancy – Learning from Satellite Observations of Magnetosphere
Dr. Evgeny Panov
Institut für Theoretische Physik - Computational Physics, TU Graz / Institut für Weltraumforschung, ÖAW
16:15 - 17:15 Tuesday 18 November 2025 TUG HS P2

Magnetic buoyancy has been known to play a role in the solar atmosphere, where it brings slender flux tubes with reduced density up through much of the convective zone. Magnetic buoyancy does operate in planetary magnetospheres, where field line curvature takes the role of gravity. Particularly, on the antisunward side of the Earth, the terrestrial magnetic field lines are stretched out to form an elongated structure called the magnetotail. In the magnetotail, magnetospheric buoyancy (gravity) waves are excited when fast earthward plasma flows break at dipolar field lines. Also, unstable buoyant plasma motions result from interchange instability. The magnetotail buoyancy phenomena participate in dissipation of the inflowing solar wind energy and thus are important for understanding the space weather. I will talk about distinctive features of magnetic buoyancy in Earth‘s magnetotail and will compare the features observed by multi-point missions THEMIS and MMS with those predicted in kinetic and MHD simulations. I will discuss the ionospheric effects of the magnetospheric buoyancy processes and questions to be answered by next generation multi-point magnetospheric missions.