Duality of the magnetic flux tube and electric current descriptions magnetospheric plasma and energy flow

Journal Article · Sun Nov 01 04:00:00 EST 1981 · Rev. Geophys. Space Phys.; (United States)

DOI:https://doi.org/10.1029/RG019i004p00617· OSTI ID:5936645

Atkinson, G

The duality between electric current and magnetic flux tubes is outlined for the magnetosphere. Magnetic flux tubes are regarded as fluid elements subjected to various stresses. Current closure then becomes the dual of stress balance, and Poynting vector energy flow a dual of J x E dissipation. The stresses acting on a flux tube are magnetic stresses, which correspond to currents at a distance, and plasma stresses, which correspond to local currents. The duality between current and stress is traced for ionospheric ion drag forces, solar wind stresses at the magnetopause, inertial effects, and the effects of energetic plasma on flux tubes. The stress balance and dual current systems are outlined for idealized magnetospheres of increasing complexity. For a simple magnetosphere with no convective flow, the balance stresses are solar wind pressure and neutral sheet plasma pressure. The corresponding current systems are the Chapman-Ferraro magnetopause currents and the magetotail current system. The introduction of convective flow introduces further stresses: ionospheric ion drag. Alfven layer shielding, and an imbalance in day-night magnetic stresses due to transport of flux tubes to the nightside by the solar wind. These stresses balance, and hence the corresponding additional currents (the ionospheric Pedersen current and the electrojets, the partial ring current, and two other current systems from the magnetopause and tail) must form a closed current system and do so by the region I and II field-aligned currents of Iijima and Potemra. The energy flow in the above models is described in terms of both Poynting vectors and the above current systems. Temporal variations examined are (1) an increase in dayside merging and/or nightside reconnection, (2) an increase in the energy density of plasma in the plasma sheet, (3) an increase in ionospheric conductivity, and (4) an increase in solar wind pressure.

• Research Organization: Herzberg Institute of Astrophysics, National Research Council, Ottawa, Canada K1A OR6
• OSTI ID: 5936645
• Journal Information: Rev. Geophys. Space Phys.; (United States), Journal Name: Rev. Geophys. Space Phys.; (United States) Vol. 19:4; ISSN RGPSB
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CURRENTS
DIFFERENTIAL EQUATIONS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTRIC FIELDS
EQUATIONS
MAGNETIC FLUX
MAGNETOSPHERE
MAXWELL EQUATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
SOLAR ACTIVITY
SOLAR WIND