Search Publications
Substorm Current Wedge Revisited
Lester, M.; Nakamura, R.; McPherron, R. L. +7 more
Almost 40 years ago the concept of the substorm current wedge was developed to explain the magnetic signatures observed on the ground and in geosynchronous orbit during substorm expansion. In the ensuing decades new observations, including radar and low-altitude spacecraft, MHD simulations, and theoretical considerations have tremendously advanced…
Current Sheets in the Earth Magnetotail: Plasma and Magnetic Field Structure with Cluster Project Observations
Nakamura, Rumi; Zelenyi, Lev; Artemyev, Anton +2 more
Thin current sheets having kinetic scales are an important plasma structure, where the magnetic energy dissipation and charged particle acceleration are the most effective. It is believed that such current sheets are self-consistently formed by the specific nonadiabatic dynamics of charged particles and play a critical role in many space plasma an…
Large-Eddy Simulations of Magnetohydrodynamic Turbulence in Heliophysics and Astrophysics
Brandenburg, Axel; Velli, Marco; Toomre, Juri +9 more
We live in an age in which high-performance computing is transforming the way we do science. Previously intractable problems are now becoming accessible by means of increasingly realistic numerical simulations. One of the most enduring and most challenging of these problems is turbulence. Yet, despite these advances, the extreme parameter regimes …
The Earth: Plasma Sources, Losses, and Transport Processes
Liemohn, Michael W.; Fazakerley, Andrew; Wang, Chih-Ping +12 more
This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et…
Solar Wind and Internally Driven Dynamics: Influences on Magnetodiscs and Auroral Responses
Paranicas, C.; Jia, X.; Delamere, P. A. +7 more
The dynamics of the giant planet magnetodiscs are strongly influenced by planetary rotation. Yet the solar wind must ultimately remove plasma from these rapidly rotating magnetodiscs at the same rate that plasma is transported radially outward from the source regions: the Io and Enceladus plasma tori. It is not clear how the solar wind influences …
What Controls the Structure and Dynamics of Earth's Magnetosphere?
Eastwood, J. P.; Fujimoto, M.; Toth, G. +2 more
Unlike most cosmic plasma structures, planetary magnetospheres can be extensively studied in situ. In particular, studies of the Earth's magnetosphere over the past few decades have resulted in a relatively good experimental understanding of both its basic structural properties and its response to changes in the impinging solar wind. In this artic…
The Role of the Ionosphere in Providing Plasma to the Terrestrial Magnetosphere—An Historical Overview
Chappell, Charles R.
Through the more than half century of space exploration, the perception and recognition of the fundamental role of the ionospheric plasma in populating the Earth's magnetosphere has evolved dramatically. A brief history of this evolution in thinking is presented. Both theory and measurements have unveiled a surprising new understanding of this imp…
A Review of General Physical and Chemical Processes Related to Plasma Sources and Losses for Solar System Magnetospheres
Delcourt, D. C.; Wurz, P.; Jackman, C. M. +13 more
The aim of this paper is to provide a review of general processes related to plasma sources, their transport, energization, and losses in the planetary magnetospheres. We provide background information as well as the most up-to-date knowledge of the comparative studies of planetary magnetospheres, with a focus on the plasma supply to each region o…
Properties of Magnetic Field Fluctuations in the Earth's Magnetotail and Implications for the General Problem of Structure Formation in Hot Plasmas
Zelenyi, Lev; Artemyev, Anton; Petrukovich, Anatoli
In this review we discuss the formation of plasma structures in hot plasmas with large β. We use spacecraft observations of magnetic field fluctuations in the Earth magnetotail to reveal the main multiscale plasma properties. Fourier spectra of magnetic field fluctuations observed by various spacecraft in the different domains of the magnetotail a…
Electric Current Circuits in Astrophysics
Frey, Harald U.; Fletcher, Lyndsay; Kuijpers, Jan
Cosmic magnetic structures have in common that they are anchored in a dynamo, that an external driver converts kinetic energy into internal magnetic energy, that this magnetic energy is transported as Poynting flux across the magnetically dominated structure, and that the magnetic energy is released in the form of particle acceleration, heating, b…