Modelling of the Solar Wind - Venus Interaction Using a Spherical Hybrid Model: Results from the First Realistic Tests

Hybrid approach allows to model the cosmic plasma interaction with non-magnetized and magnetized planetary objects efficiently. In a hybrid model ions are represented as particles while electrons form a massless, charge neutralizing fluid. The HYB hybrid model family has been developed at the Finnish Meteorological Institute (FMI) and used successfully to describe how the flowing plasma interacts with such Solar System bodies as Mercury, Venus, the Moon, Mars, Saturnian moon Titan and asteroids. The HYB model assumes cube shaped grid cells. However taking into account that planetary worlds are not Cartesian, developing a spherical coordinate version of the model (HYBs) would allow a more precise representation of the real situation. Important advantages of the spherical grid compared with the Cartesian grid, are: 1) better grid resolution, because the grid size decreases automatically near the obstacle (the planetary surface) and 2) Natural boundary conditions for the obstacle, because the planetary surface overlaps r-constant surface of the grid. We represent the results from the first realistic test runs of the solar wind interaction with Venus utilizing the spherical grid in the HYB model.