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Plasma Reconnection, Shocks and Turbulence in Solar System Interactions: Modelling and Observations

Periodic Reporting for period 5 - PRESTISSIMO (Plasma Reconnection, Shocks and Turbulence in Solar System Interactions: Modelling and Observations)

Período documentado: 2021-03-01 hasta 2022-05-31

This project combines the forefront space physics with top-tier high performance computing. Three phenomena are above others in importance in explaining plasma behaviour in the Solar–Terrestrial system, laboratories, fusion devices, and astrophysical domains: 1) magnetic reconnection enabling energy and mass transfer between magnetic domains, 2) collisionless shocks forming due to supersonic relative flow speeds between plasmas, and 3) particle acceleration associated with both. These processes are critical in understanding the scientific foundation of space weather, i.e. harmful effects caused by enhanced radiation and dynamical processes that endanger space- and ground-based technological systems or human life. Space weather forecasts require physics-based models; however, to date only simple plasma descriptions have been used in the global context. We have developed the first 6-dimensional global magnetospheric kinetic simulation in the world, Vlasiator, promising a grand leap both in understanding fundamental space plasma physics, and in improving the accuracy of present space weather models. Combining the unique Vlasiator with newest spacecraft data, local kinetic physics can be interpreted in global context in a ground-breaking fashion.
The overall objectives are to investigate
- Near-Earth reconnection, 2028
- Ion-scale phenomena in the near-Earth shocks, 2028
- Particle acceleration by shocks and reconnection, 2028
- Inner magnetospheric wave-particle processes, and the consequent particle precipitation into the ionosphere. 2028

The project includes four work packages (WP). The first package develops Vlasiator used in the other WPs. WP2 investigates local physics in small scales, and compares to individual in situ observations. WP2 leads to a better understanding of physical processes and scenarios in WP3, taking place in a larger area and requiring global modelling and observations from multiple spacecraft and measurement arrays. The detailed physical and system-level understanding in WP2 and WP3 allows a better description of space weather, better understanding of solar forcing on climate and plasma physics in universal setups, better requirements for instruments and missions, and better HPC techniques, leading to well-described impacts. In WP4 we also make it easy for others to multiply physical understanding in topics we cover but which are not our primary goals.
The work in WP1 (Development) ensures that the modelling tool Vlasiator is capable of addressing the physics in WP2-WP4. The main achievement during the reporting period is the first global 6D run carried out in summer 2019. This is the first such modelling result in the world, promising a grand leap in space physics.
WP2 on small-scale physics: Two important highlights are reported, both of which are at the heart of understanding the science of space weather. First, Hoilijoki et al. (2019, a JGR cover article) investigated in detail how energy transfers from the solar wind into the domain controlled by Earth’s magnetic field. Turc et al., 2019 investigated how the solar storms vary the sound of waves before they encounter the near-Earth space. This paper generated a world-wide attention as the paper was highlighted in a European Space Agency (ESA) press release.
As part of WP3 on large-scale physics: The most important achievement is Grandin et al. (2019), which studied the signatures at the auroral region originating from variations within the near-Earth space and the dynamics within. This was the first study, which can self-consistently interpret the particle signatures at the ionosphere in terms of variations within the nightside of the near-Earth space. Further, as a highlight, we were selected as PIs to form an International Space Science Institute team, gathering international scientists to study ULF wave transmission.
WP4 (Impact) holds a Vlasiator workshop, expands the Vlasiator community to other domains, distributes data, collaborates with different missions using Vlasiator data, and discusses with the 24/7 space weather service at FMI. All items were carried out as planned. Workshop was held, Vlasiator is being discussed to be utilized in Mercury and Mars, different mission teams have been helped with Vlasiator data, and discussions have been held with the 24/7 space weather service.
The impacts of the project are categorised in four main types, by 1) addressing the absolute key questions in solar system plasma physics, 2) significantly aiding adjacent fields, 3) contributing to high-level technological innovations, and 4) providing a much improved scientific basis for societal challenges.
On 1 (key questions), all the published papers during the period concern new phenomena that are not observed before, and therefore are clearly beyond state of the art. The first 6D global model of the near-Earth space is an extraordinary achievement.
On 2) (adjacent fields), we have started a dialogue with fusion, astrophysics, and planetary communities. Vlasiator has been reviewed in terms of two different fusion setups, and two teams have downloaded it to be utilized at Mars and Mercury.
On 3) (technical innovations), Vlasiator is a partner code for CSC – IT Center for Science, Intel, and Nvidia, and Vlasiator has participated hackathons organized by these industry partners. Especially the parallelization techniques in use are technical innovations for the high performance community.
On 4) (societal challenges), the project team has continuously consulted the Finnish Meteorological Institute Space weather 24/7 service about space physics. Vlasiator has also been presented widely in the Finnish media, drawing attention to space weather in general. M Palmroth is a wanted speaker in this context, both in public lectures and in media in general. During the reporting period two books featuring Palmroth, and one international documentary about Vlasiator, were published.
Near-Earth space in Vlasiator, world's most accurate space environment simulation.