Global hybrid model of the solar wind interaction with the Venus ionosphere: ion escape processes

Abstract. 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)

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Modulation of the solar wind driven ion escape from unmagnetized planets by ultra-low-frequency foreshock waves in a global hybrid simulation

10.5194/egusphere-egu2020-6891 ◽

2020 ◽

Author(s):

Riku Jarvinen ◽

Esa Kallio ◽

Tuija Pulkkinen

Keyword(s):

Solar Wind ◽

Large Scale ◽

Low Frequency ◽

Hybrid Simulation ◽

Bow Shock ◽

Upstream Region ◽

Ulf Waves ◽

Solar Wind Interaction ◽

Ion Escape ◽

A Charge

We study the solar wind interaction with Venus in a 3-dimensional global hybrid model where ions are treated as particles and electrons are a charge-neutralizing fluid. We concentrate on large-scale ultra-low frequency (ULF) waves in the ion foreshock and how they affect the energization and escape of planetary ions. The ion foreshock forms in the upstream region ahead of the quasi-parallel bow shock, where the angle between the shock normal and the magnetic field is smaller than about 45 degrees. The magnetic connection with the bow shock allows backstreaming of the solar wind ions leading to the formation of the ion foreshock. This kind of beam-plasma configuration is a source of free energy for the excitation of plasma waves. The foreshock ULF waves convect downstream with the solar wind flow and encounter the bow shock and transmit in the downstream region. We analyze the coupling of the ULF waves with the planetary ion acceleration and compare Venus and Mars in a global hybrid simulation.

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Mars-solar wind interaction: LatHyS, an improved parallel 3-D multispecies hybrid model

Journal of Geophysical Research Space Physics ◽

10.1002/2015ja022324 ◽

2016 ◽

Vol 121 (7) ◽

pp. 6378-6399 ◽

Cited By ~ 18

Author(s):

Ronan Modolo ◽

Sebastien Hess ◽

Marco Mancini ◽

Francois Leblanc ◽

Jean-Yves Chaufray ◽

...

Keyword(s):

Solar Wind ◽

Hybrid Model ◽

Solar Wind Interaction

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A new 3-D spherical hybrid model for solar wind interaction studies

Journal of Geophysical Research Space Physics ◽

10.1002/jgra.50497 ◽

2013 ◽

Vol 118 (8) ◽

pp. 5157-5168 ◽

Cited By ~ 6

Author(s):

S. Dyadechkin ◽

E. Kallio ◽

R. Jarvinen

Keyword(s):

Solar Wind ◽

Hybrid Model ◽

Solar Wind Interaction ◽

Interaction Studies

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Oxygen ion escape from Venus in a global hybrid simulation: role of the ionospheric O+ ions

Annales Geophysicae ◽

10.5194/angeo-27-4333-2009 ◽

2009 ◽

Vol 27 (11) ◽

pp. 4333-4348 ◽

Cited By ~ 26

Author(s):

R. Jarvinen ◽

E. Kallio ◽

P. Janhunen ◽

S. Barabash ◽

T. L. Zhang ◽

...

Keyword(s):

Solar Wind ◽

Hybrid Simulation ◽

Solar Wind Interaction ◽

Simulation Code ◽

Oxygen Ion ◽

Ion Escape ◽

Global Configuration ◽

Best Fit ◽

The Magnetic Field

Abstract. We study the solar wind induced oxygen ion escape from Venus' upper atmosphere and the Venus Express observations of the Venus-solar wind interaction by the HYB-Venus hybrid simulation code. We compare the simulation to the magnetic field and ion observations during an orbit of nominal upstream conditions. Further, we study the response of the induced magnetosphere to the emission of planetary ions. The hybrid simulation is found to be able to reproduce the main observed regions of the Venusian plasma environment: the bow shock (both perpendicular and parallel regions), the magnetic barrier, the central tail current sheet, the magnetic tail lobes, the magnetosheath and the planetary wake. The simulation is found to best fit the observations when the planetary \\oxy~escape rate is in the range from 3×1024 s−1 to 1.5×1025 s−1. This range was also found to be a limit for a test particle-like behaviour of the planetary ions: the higher escape rates manifest themselves in a different global configuration of the Venusian induced magnetosphere.

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Aspects of solar wind interaction with Mars: comparison of fluid and hybrid simulations

Annales Geophysicae ◽

10.5194/angeo-25-145-2007 ◽

2007 ◽

Vol 25 (1) ◽

pp. 145-159

Author(s):

N. V. Erkaev ◽

A. Bößwetter ◽

U. Motschmann ◽

H. K. Biernat

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Hybrid Model ◽

Field Enhancement ◽

Bow Shock ◽

Solar Wind Interaction ◽

Plasma Parameters ◽

Physical Reason ◽

The Magnetic Field ◽

Hybrid Simulations

Abstract. Mars has no global intrinsic magnetic field, and consequently the solar wind plasma interacts directly with the planetary ionosphere. The main factors of this interaction are: thermalization of plasma after the bow shock, ion pick-up process, and the magnetic barrier effect, which results in the magnetic field enhancement in the vicinity of the obstacle. Results of ideal magnetohydrodynamic and hybrid simulations are compared in the subsolar magnetosheath region. Good agreement between the models is obtained for the magnetic field and plasma parameters just after the shock front, and also for the magnetic field profiles in the magnetosheath. Both models predict similar positions of the proton stoppage boundary, which is known as the ion composition boundary. This comparison allows one to estimate applicability of magnetohydrodynamics for Mars, and also to check the consistency of the hybrid model with Rankine-Hugoniot conditions at the bow shock. An additional effect existing only in the hybrid model is a diffusive penetration of the magnetic field inside the ionosphere. Collisions between ions and neutrals are analyzed as a possible physical reason for the magnetic diffusion seen in the hybrid simulations.

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Modulation of ion escape by ultra-low frequency waves at Venus and Mars in a global hybrid simulation

10.5194/epsc2021-170 ◽

2021 ◽

Author(s):

Riku Jarvinen ◽

Esa Kallio ◽

Tuija Pulkkinen

Keyword(s):

Solar Wind ◽

Electric Fields ◽

Hybrid Model ◽

Low Frequency ◽

Heavy Ion ◽

Ulf Waves ◽

Space Resolution ◽

Ion Escape ◽

Particle Clouds ◽

A Charge

We investigate the effect of foreshock ultra-low frequency (ULF) waves on the solar wind induced heavy ion escape from Venus and Mars in a global hybrid model. The foreshock ULF waves are excited by backstreaming ion populations scattered at the quasi-parallel bow shock, and convect downstream with the solar wind. In the model, the waves affect magnetic and electric fields in the Venusian and Martian plasma environments causing fluctuations in the heavy ion acceleration processes such as the solar wind ion pickup. This leads to significant modulations in global escape rates of ionized planetary volatiles at the ULF wave frequency. We study this process in a global hybrid model, where ions are treated as particle clouds moving under the Lorentz force and electrons are a charge-neutralizing fluid. The analyzed simulation runs use more than 200 simulation particle clouds per cell on average to allow enough velocity space resolution for resolving foreshock, wave phenomena and ion escape processes self-consistently. We find that at Venus the global ion escape is modulated by the ULF waves even under nominal solar wind and IMF upstream conditions, while at Mars the modulation becomes significant under a strongly radial IMF orientation.

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