Poster presentations and abstracts

We study the solar wind interaction with Venus and Mercury in a 3-dimensional global hybrid simulation where ions are treated as particles and electrons are a charge-neutralizing fluid. We concentrate on the formation of large-scale ultra-low frequency (ULF) waves in ion foreshocks and their dependence on the solar wind and interplanetary magnetic field conditions. 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. We compare the waves between Venus and Mercury, and analyze the coupling of the ULF waves with the planetary ion acceleration at Venus.

References:

Jarvinen R., Alho M., Kallio E., Pulkkinen T.I., 2020, Oxygen Ion Escape From Venus Is Modulated by Ultra-Low Frequency Waves, Geophys. Res. Lett., 47, 11, doi:10.1029/2020GL087462

Jarvinen R., Alho M., Kallio E., Pulkkinen T.I., 2020, Ultra-low frequency waves in the ion foreshock of Mercury: A global hybrid modeling study, Mon. Notices Royal Astron. Soc., 491, 3, 4147-4161, doi:10.1093/mnras/stz3257

How to cite: Jarvinen, R., Kallio, E., and Pulkkinen, T. I.: Ultra-low frequency foreshock waves at Venus and Mercury in a global hybrid simulation, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-202, https://doi.org/10.5194/epsc2020-202, 2020.

The evolving ambient solar wind is one of the key links between the Sun and planetary bodies in our solar system. Here we present a comprehensive catalogue of solar wind properties, stream interaction regions, and coronal mass ejections at different locations in the inner heliosphere. Our database incorporates observational data products and also solar wind modelling results. The solar wind modelling is based on two different approaches for modelling the conditions in the ambient solar wind. While the WSA/THUX model combination solves the viscous form of the underlying Burgers equation to compute the two-dimensional solar wind conditions in our solar system, the second approach is a computationally fast machine learning method for predicting the ambient solar wind flows at Earth. Statistics of the ambient solar wind model results for more than 15 years in combination with a catalogue of coronal mass ejections observed at the Earth, Mars and STEREO satellites along with stream interaction regions provide a comprehensive overview of the past and present solar wind behaviour for shaping planetary space weather.

How to cite: Bailey, R., Reiss, M., Möstl, C., Amerstorfer, U., Simon Wedlund, C., Amerstorfer, T., Weiss, A., Hinterreiter, J., Guo, J., von Forstner, J., Barnes, D., Davies, J., and Harrison, R.: A comprehensive catalogue of solar wind properties and events in the inner heliosphere, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-562, https://doi.org/10.5194/epsc2020-562, 2020.

The trapping of charged particles in planetary magnetic fields is a process which underpins many important aspects of planetary magnetospheres, such as ring current evolution, particle acceleration, and the flow of current through the system, both free and bound. As part of our effort for the Europlanet project, the UCL group have developed codes which accurately model the trajectories of charged particles in magnetic field models appropriate for the magnetospheres of Jupiter and Saturn. These will form the basis of a service for the SPIDER task. In this presentation, we show examples of ion trajectories at both planets for representative 'start values' of equatorial distance, pitch angle, and values of particle energy. The simulations provide an indication of how particle orbits become less adiabatic as one approaches energies where gyroradii become comparable to magnetic field curvature radius. The disk-like fields of the gas giants are particularly effective at 'scattering' adequately high-energy particle trajectories as they cross the equator, where the field lines are most 'pinched' and have the smallest length scales.

How to cite: Guio, P., Achilleos, N., and André, N.: Particle Motions in Planetary Magnetic Fields: Europlanet Service, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-851, https://doi.org/10.5194/epsc2020-851, 2020.