| Quasi-neutral hybrid
model is a self-consistent modelling approach that includes positively charged
particles and an electron fluid. The approach has received an increasing
interest in space plasma physics research because it makes it possible to study
several plasma physical processes that are difficult or impossible to model by
self-consistent fluid models, such as the effects associated with the ions’
finite gyroradius, the velocity difference between different ion species, or
the non-Maxwellian velocity distribution function. By now quasi-neutral hybrid
models have been used to study the solar wind interaction with the non-magnetised
Solar System bodies of Mars, Venus, Titan and comets. Localized,
two-dimensional hybrid model runs have also been made to study terrestrial
dayside magnetosheath. However, the Hermean plasma environment has not yet been
analysed by a global quasi-neutral hybrid model.
In this paper we present a new quasi-neutral hybrid model
developed to study various processes associated with the Mercury-solar wind
interaction. Emphasis is placed on addressing advantages and disadvantages of
the approach to study different plasma physical processes near the planet. The
basic assumptions of the approach and the algorithms used in the new model are
thoroughly presented. Finally, some of the first three-dimensional hybrid model
runs made for Mercury are presented.
The resulting macroscopic plasma parameters and the
morphology of the magnetic field demonstrate the applicability of the new
approach to study the Mercury-solar wind interaction globally. In addition, the
real advantage of the kinetic hybrid model approach is to study the property of
individual ions, and the study clearly demonstrates the large potential of the
approach to address these more detailed issues by a quasi-neutral hybrid model
in the future.
Key words. Magnetospheric physics
(planetary magnetospheres; solar wind-magnetosphere interactions) – Space
plasma physics (numerical simulation studies) |