Magnetic Reconnection in Plasmas

First global 3D two-way coupled MHD-EPIC simulation of a magnetosphere: Ganymede

13 Aug 2015, 16:10

25m

FD5 (FD5)

Oral Workshop, August 10-14 Afternoon IV

Speaker

Dr Stefano Markidis (KTH)

Description

We present the first 3D global simulation of Ganymede’s magnetosphere in a unified framework coupling the fluid and kinetic models. An MHD model describes the global interaction of solar wind with Ganymede’s magnetosphere over the whole simulation domain. A kinetic model is used only in the selected space regions, where kinetic effects dominate and MHD description fails. In particular, kinetic regions are used in Ganymede magnetotail and dayside magnetopause to correctly describe magnetic reconnection in these regions. This is the first simulation capable of combining fluid and kinetic approaches in a realistic large-scale simulation of a planet’s magnetosphere. In this work, the BATS-R-US MHD code is coupled with the iPIC3D Particle-in-Cell kinetic code. The coupling is two-way as both the MHD and kinetic codes provide reciprocal feedback. The electromagnetic fields of the fluid region are used as the boundary conditions for the electromagnetic fields in the kinetic regions; the fluid pressure tensor is used to sample distribution functions at the boundary of the kinetic regions. On the other hand, the kinetic areas provide the fluid regions the correct electromagnetic field values calculated with the kinetic approach. The coupling of the two codes has been realized within the SWMF framework, a highly scalable parallel environment for space weather modeling. The software coupling is achieved by using message passing among different BATS-R-US and iPIC3D instances that can run on different computational resources. In this talk, we present the coupling strategy that enabled the first global fluid-kinetic simulation of Ganymede’s magnetosphere and the simulation results of the solar wind interaction with Ganymede’s magnetosphere focusing on the kinetic magnetic reconnection in magnetotail and in dayside magnetopause. Finally, we discuss the impact and application of this work to other planetary magnetosphere.