HAO Colloquium Series Presents Kevin Dalmasse, CISL/HAO

Injection and release of free energy, magnetic helicity, and electric currents in the solar atmosphere

In the solar atmosphere, the signatures of solar activity are transient, localized brightenings, during which a localized region is rapidly and temporarily heated, i.e., solar flares. The origin of solar flares is magnetic and comes from the evolution of current-carrying magnetic fields. These magnetic fields are essential for solar activity because they store the magnetic energy that can be released during solar flares. The work that I did during my PhD aimed at better understanding and quantifying the role of current-carrying magnetic fields for solar activity in the framework of magnetohydrodynamics (MHD). For that purpose, I jointly studied three physical quantities, the properties of which give information on the properties of eruptive magnetic fields: relative magnetic helicity (which quantifies the geometrical properties of the magnetic field, i.e., its shear, its twist); electric currents; and free magnetic energy (the magnetic energy of the current-carrying magnetic fields). After a general introduction, I will present the results of this work.

Date and time: 
Wednesday, January 14, 2015 - 1:30pm to 2:30pm
South Auditorium