Magnetic Reconnection in Plasmas

Reconnection in Vlasiator: 1 The global system

13 Aug 2015, 15:45

25m

FD5 (FD5)

Invited Workshop, August 10-14 Afternoon IV

Speaker

Prof. Minna Palmroth (Finnish Meteorological Institute, Helsinki, Finland)

Description

Vlasiator (http://vlasiator.fmi.fi) is a newly developed, global hybrid- Vlasov simulation, which solves the six-dimensional phase space utilising the Vlasov equation for protons, while electrons are treated as a charge-neutralising fluid. The outcome of the simulation is a global reproduction of ion-scale physics where the generation of physical features can be followed in time and their consequences can be quantitatively characterised. Vlasiator produces the ion distribution functions and the related kinetic physics in unprecedented detail, in the global scale magnetospheric scale with a resolution of a couple of hundred kilometres in the ordinary space and about 30 km/s in the velocity space. We currently run Vlasiator under a southward IMF in five dimensions consisting of a three-dimensional velocity space embedded in the polar (XZ) plane. The simulation box extends 40 Earth radii (RE) in the solar wind upstream direction and a hundred RE in the nightside, thus including the dayside and the nightside reconnection sites in a single simulation volume. This introduces an opportunity to investigate kinetic reconnection physics in the global system, from the solar wind, through the magnetosheath and magnetopause, and eventually the nightside reconnection as a consequence of other processes with realistic boundary conditions. We observe the formation of 2- dimensional representations of flux transfer events at the magnetopause, and a substorm process in the nightside. We quantify reconnection rates and other relevant reconnection parameters and compare to earlier literature, with the aim of discussing the substorm process as a consequence of the global system evolution.