Vlasiator

 

Vlasiator - hybrid-Vlasov simulation code

The Finnish Meteorological Institute is developing a 6-dimensional Vlasov theory-based simulation called Vlasiator. The focus is to simulate the entire near-Earth space at a global scale using the kinetic hybrid-Vlasov approach, to study fundamental plasma processes (reconnection, particle acceleration, shocks) and gain a deeper understanding of space weather.

Space weather is a term used to describe the variable environmental effects within near-Earth space, caused by the Sun emitting solar wind, a stream of charged particles carrying the solar electromagnetic field. Space weather can be caused by solar high-energy particles or by dynamic variations of the solar wind that can cause extended periods of major disturbances on ground and space, affecting technological systems (e.g., telecommunication and weather spacecraft at geostationary orbit, and ground-based power grids).

In Vlasiator, ions are represented as velocity distribution functions, while electrons are magnetohydrodynamic fluid, enabling a self-consistent global plasma simulation that can describe multi-temperature plasmas to resolve non-MHD processes that currently cannot be self-consistently described by the existing global space weather simulations. The novelty is that by modelling ions as velocity distribution functions the outcome will be numerically noiseless.

Due to the multi-dimensional approach at ion scales, Vlasiator's computational challenges are immense. We use advanced high performance computing techniques to allow massively parallel computations on tens of thousands of cores.

More details about the implementation can be found on the code description page, and in the presentations and publications, especially this paper.