30.11. 2015

Electron energetics in the expanding solar wind

Electron energetics in the expanding solar wind
Detailed statistical analysis of electron energetic properties as measured by HELIOS 1&2 spacecraft indicates that for the non-adiabatic cooling of electrons in the expanding solar wind no significant external heating mechanisms are required.
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15.12. 2014

Electron heat flux in the solar wind: Data vs. Simulations

Electron heat flux in the solar wind: Data vs. Simulations
Numerical simulations, which include the effects of binary collisions, are able to reproduce qualitatively and quantitatively the electron heat flux in the solar wind observed at 1 AU.
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30.06. 2014

Particle-in-Cell Simulations of Magnetic Reconnection in Collisionless Force-Free Current Sheets

Magnetic reconnection is one of the most fundamental physical processes in plasmas. It is especially important for activity processes in space and astrophysical plasmas. We investigate magnetic reconnection in collisionless plasmas, focussing on current sheet configurations for which the current density is parallel to the magnetic field, i.e. force-free current sheets.
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10.06. 2014

Research Review #2

Much of our understanding of collisionless shocks comes from studies of the terrestrial bow shock upstream of the magnetosphere, which serves to slow down and thermalize the incident supersonic and super-Alfvenic plasma in the solar wind. Over the last decades, multi-spacecraft observations and computer simulations have helped to enhance our understanding of the physical process involved, and progress is still being made. In particular, 3D simulations of the shock front are now becoming feasible, something which will allow full spatial and temporal investigations of the shock processes. Some of the problems that yet remain unresolved are for example how the highly energetic field-aligned beams observed in the quasi-parallel section of the bow shock (i.e. where the shock normal is within 45 degrees of the upstream magnetic field) gain their initial energies, and the possible non-stationary features and reformation of the quasi-perpendicular shock front (i.e. where the angle between the shock normal and the upstream magnetic field exceeds 45 degrees) which has earlier been considered as a stable boundary.
Below is a short summary of four papers published within the last year that investigate several such issues, and which are all directly relevant to the work conducted within the SHOCK project.
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06.05. 2014

The role of binary collisions in the electron properties of the solar wind

The role of binary collisions in the electron properties of the solar wind
Numerical simulations show that the effect of the radial expansion and the binary collisions between electrons play a significant role in shaping the observed velocity distribution function.
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27.11. 2012

Research Review #1

This blog post presents some highlights of recent simulation research from published research papers from outside the SHOCK consortium, dealing with topics such as the solar wind interaction with the Moon and the formation of very small scale structures in solar wind turbulence.

Simulation is used extensively in heliospheric research to investigate the evolution of the solar wind and its interaction with solar system bodies such as the Earth and other planets. The SHOCK project has the aim of furthering this research and also extending the use of simulations in data analysis of space data. As well as the main research areas of the SHOCK project consortium members, it is important to show the wide range of heliospheric simulation work.
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23.04. 2012

Reconnection in Space Plasmas

The storage and release of magnetic energy is fundamental for many activity processes in solar system and astrophysical plasmas. When magnetic energy is released the magnetic field lines often reconfigure in a process which scientists call magnetic reconnection.
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19.04. 2012

Solar Wind – Time Development of Waves

The solar wind is a high flow of plasma from the Sun which fills the solar system. As the solar wind flows away from the Sun it expands, and this expansion changes the particle distribution function within the plasma. This can only happen because the plasma is very low density and very high temperature so that it is collisionless, which means that the particle distribution functions are not forced to be stable Maxwellian distributions as in a normal gas.
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18.04. 2012

Quasi-Trapped Particles in the Hermean Magnetosphere

Mercury has its own magnetic field as has been revealed by Mariner 10 in 1970's and confirmed by NASA's MESSENGER mission recently. Even if the planetary magnetic dipole strength is about 2500 times smaller, it is sufficient to form magnetosphere structure similar to the Earth's magnetosphere. Due to the minimum data from in-situ measurements, there are lot of open questions on the magnetospheric properties and processes. Global numerical simulations helps to address and answer some of them. Simulations proved useful for predictions of features to be investigated using real data and they give global context to local measurements.
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  • ERA
  • ESA
  • Queen Mary
  • CNRS
  • ASU
  • Sprinx systems
  • University of St. Andrews