Notice:
|
Found 4 entries in the Bibliography.
Showing entries from 1 through 4
2018 |
Magnetic Helicity Reversal in the Corona at Small Plasma Beta Solar and stellar dynamos shed small-scale and large-scale magnetic helicity of opposite signs. However, solar wind observations and simulations have shown that some distance above the dynamo both the small-scale and large-scale magnetic helicities have reversed signs. With realistic simulations of the solar corona above an active region now being available, we have access to the magnetic field and current density along coronal loops. We show that a sign reversal in the horizontal averages of the magnetic helicity occurs ... Bourdin, Philippe; Singh, Nishant; Brandenburg, Axel; Published by: The Astrophysical Journal Published on: 12/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aae97a Astrophysics - Solar and Stellar Astrophysics; dynamo; magnetohydrodynamics: MHD; methods: numerical; parker solar probe; Physics - Plasma Physics; Solar Probe Plus; Solar wind; Sun: corona; Sun: magnetic fields |
Deep-space exploration of the inner heliosphere is in an unprecedented golden age, with the recent and forthcoming launches of the Parker Solar Probe (PSP) and Solar Orbiter (SolO) missions, respectively. In order to both predict and understand the prospective observations by PSP and SolO, we perform forward MHD modeling of the 3D inner heliosphere at solar minimum, and synthesize the white-light (WL) emission that would result from Thomson scattering of sunlight from the coronal and heliospheric plasmas. Both solar rotat ... Xiong, Ming; Davies, Jackie; Feng, Xueshang; Li, Bo; Yang, Liping; Xia, Lidong; Harrison, Richard; Hayashi, Keiji; Li, Huichao; Zhou, Yufen; Published by: The Astrophysical Journal Published on: 12/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aae978 magnetohydrodynamics: MHD; methods: numerical; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere |
Parametric Decay and the Origin of the Low-frequency Alfv\ enic Spectrum of the Solar Wind The fast solar wind shows a wide spectrum of transverse magnetic and velocity field perturbations. These perturbations are strongly correlated in the sense of Alfv\ en waves propagating mostly outward, from the Sun to the interplanetary medium. They are likely to be fundamental to the acceleration and the heating of the solar wind. However, the precise origin of the broadband spectrum is unknown to date. Typical periods of chromospheric Alfv\ en waves are limited to a few minutes, and any longer period perturbations shoul ... eville, Victor; Tenerani, Anna; Velli, Marco; Published by: The Astrophysical Journal Published on: 10/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aadb8f instabilities; magnetohydrodynamics: MHD; methods: numerical; parker solar probe; Solar Probe Plus; Solar wind; waves |
2016 |
SOLAR WIND COLLISIONAL AGE FROM A GLOBAL MAGNETOHYDRODYNAMICS SIMULATION Simple estimates of the number of Coulomb collisions experienced by the interplanetary plasma to the point of observation, I.e., the \textquotedblleftcollisional age\textquotedblright, can be usefully employed in the study of non-thermal features of the solar wind. Usually these estimates are based on local plasma properties at the point of observation. Here we improve the method of estimation of the collisional age by employing solutions obtained from global three-dimensional magnetohydrodynamics simulations. This enable ... Chhiber, R; Usmanov, AV; Matthaeus, WH; Goldstein, ML; Published by: The Astrophysical Journal Published on: 04/2016 YEAR: 2016   DOI: 10.3847/0004-637X/821/1/34 magnetohydrodynamics: MHD; methods: numerical; parker solar probe; plasmas; scattering; Solar Probe Plus; Solar wind; turbulence |
1