Colloquium: 6-dimensional modelling of the near-Earth space
University of Helsinki, Finland
will introduce us to the art of modelling of the near-Earth plasma environment
This talk presents the world’s most accurate space environment simulation tool, Vlasiator. But why is modelling the near-Earth space important? Because we live here, on our planet. Space is being utilised almost at an exponential speed. Both the hundreds of billions of dollars invested into space, and our way of life is at stake, if we do not understand how the near-Earth space works. Therefore, it is crucial to both model and measure the near-Earth space.
Numerical simulations are key in modern space physics, as they can be used as 1) context to data, 2) predict future behaviour of the system, 3) understand the system using unforeseen boundary conditions, and increasingly also in 4) discovering new phenomena that are hard to be observed using point-wise satellite measurements. Especially, the discovery of new phenomena pertains to global systems, where phenomena of interest may be initiated far away from the point of observations. Vlasiator is the world’s first and so far the only global simulation based on the hybrid-Vlasov approach that simulates the ion distributions accurately without noise. Vlasiator has shown without a doubt that ion-kinetic effects cannot be neglected from the large scales, as small-scale phenomena affect large scales and vice versa. This scale coupling leads to phenomena that are not predicted using previous simulations, or with spacecraft measurements. This talk presents the first 6D global simulation runs of the near-Earth space and discusses how challenging it was to develop this modelling tool.