MPS Seminar: Solar flares, current sheets, and finite-time singularities in Hall MHD (Y. Litvinenko)

Observational data and theoretical models strongly suggest that reconnecting current sheets, separating the interacting magnetic fluxes in the solar corona, play the key role in the dynamics and energetics of solar flares. The formation of a current sheet in a weakly collisional coronal plasma can be modelled using Hall MHD equations. After reviewing the relevant solar data and the basic properties of reconnecting current sheets, I will present a class of solutions for current sheet formation. I will show that, in sharp contrast to two-dimensional solutions in standard MHD, a finite-time collapse to the current sheet can occur in Hall MHD, which may help to explain the explosive character of energy release in solar flares.