lundi 8 avril 2019, par Kostas Moraitis (LESIA)
Jeudi 25 avril 2019 à 15h00 , Lieu : Salle de rĂ©union du bâtiment 14
This talk summarizes three recent works regarding magnetic helicity, which is a measure of the geometrical complexity of a 3D magnetic field and a conserved quantity of ideal MHD. The first work is about an accurate method to compute relative magnetic helicity, the appropriate helicity for most natural plasmas, in spherical geometry, and especially in finite volumes. The second work deals with a method to visualize relative magnetic helicity through a density proxy called field line helicity. In the third work, after studying the evolution of relative magnetic helicity in a solar active region, we discuss the possibility of indicating AR eruptivity with helicity-related quantities.
