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Solar Surface and Atmospheric Dynamics. The Photosphere
Martínez Pillet, V.
Various aspects of the magnetism of the quiet sun are reviewed. The suggestion that a small scale dynamo acting at granular scales generates what we call the quiet sun fields is studied in some detail. Although dynamo action has been proved numerically, it is argued that current simulations are still far from achieving the complexity that might be…
Solar Wind Conditions and Composition During the Genesis Mission as Measured by in situ Spacecraft
Neugebauer, Marcia; Wiens, Roger C.; Zurbuchen, Thomas H. +4 more
We describe the Genesis mission solar-wind sample collection period and the solar wind conditions at the L1 point during this 2.3-year period. In order to relate the solar wind samples to solar composition, the conditions under which the samples were collected must be understood in the context of the long-term solar wind. We find that the state of…
Cosmic Rays Through the Solar Hale Cycle. Insights from Ulysses
Heber, B.
The Ulysses spacecraft had been the first to orbit the Sun over its poles and to explore the heliosphere at these high heliolatitudes. It has now completed three fast latitude scans, two at solar minimum and one at solar maximum. Since its launch in October 1990, this mission has led to several surprising discoveries concerning energetic particles…
The Heliospheric Magnetic Field
Balogh, André; Erdõs, Géza
The Heliospheric Magnetic Field (HMF) is the physical framework in which energetic particles and cosmic rays propagate. Changes in the large scale structure of the magnetic field lead to short- and long term changes in cosmic ray intensities, in particular in anti-phase with solar activity. The origin of the HMF in the corona is well understood an…
Mechanisms of Spontaneous Reconnection: From Magnetospheric to Fusion Plasma
Zelenyi, Lev; Artemyev, Anton
Very often space plasma is treated as collisionless. We check the validity of this paradigm considering various regimes of tearing mode (spontaneous reconnection) including effects of particle collisions and shear of magnetic field. We briefly describe Pitaevskii's effect of effective modification of collision frequency due to the finite particle …
Microphysics in Astrophysical Plasmas
Schwartz, Steven J.; Zweibel, Ellen G.; Goldman, Martin
Although macroscale features dominate astrophysical images and energetics, the physics is controlled through microscale transport processes (conduction, diffusion) that mediate the flow of mass, momentum, energy, and charge. These microphysical processes manifest themselves in key (all) boundary layers and also operate within the body of the plasm…