Magnetic reconnection: MHD theory and modelling

Abstract In this review we focus on the fundamental theory of magnetohydrodynamic reconnection, together with applications to understanding a wide range dynamic processes in solar corona, such as flares, jets, coronal mass ejections, wind and heating. We summarise only briefly related topics collisionless non-thermal particle acceleration, reconnection systems other than corona. introduce several preliminary that are necessary before subtleties can be fully described: these include null points (Sects. 2.1–2.2), topological geometrical features separatrices, separators quasi-separatrix layers 2.3, 2.6), conservation magnetic flux field lines (Sect. 3), helicity 4.6). Formation current sheets two- three-dimensional fields is reviewed Sect. 5. These set scene for discussion definition properties three dimensions covers conditions failure concept velocity, nature diffusion, differences between two-dimensional 4). Classical 2D models presented, including annihilation 6), slow fast regimes steady 7), non-steady tearing mode 8). Then routes collisional or medium described 9). The remainder dedicated our how operates complex Sun’s Sects. 10–12, 14.1 different possible summarised, at point, separator, quasi-separator braid. role 3D flares 13) reviewed, well heating 14), release 15.2). Extensions magnetosphere 15.3), link turbulence 16), acceleration 17) mentioned.