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Magnetospheric currents are very diverse and dynamical. The magnetopause shrinks, expands, and erodes, with varying degree of connection to the IMF. Intrusion of the plasma in the polar cusps results in diamagnetic currents which depress the field at high latitudes. The tail current sheet warps, bends, and twists, and its current density varies as the tail stretches and rebounds. Birkeland currents vary with the IMF and with the substorm cycle, and the ring current builds up and decays in the course of storms. During substorms, a dynamical current wedge develops on the nightside, resulting in a rapid reconfiguration of the near-Earth field. The data-based approach to magnetospheric modeling is to develop a flexible representation for the magnetic field vector and fit it to a large set of spacecraft data. All the above currents should be represented in the models in a meaningful way, and substantial advance was made recently in this direction. The new models feature a continuous parametric dependence on the solar wind conditions, include Birkeland currents, and have a solar-wind controlled magnetopause with a penetration of the IMF. New techniques are now available for modeling the twisting and warping of the cross-tail current, the collapse of the tail field during substorms, and the observed structure of the polar cusps. This article overviews some of those developments.

Original languageEnglish
Title of host publicationMAGNETOSPHERIC CURRENT SYSTEMS
EditorsS Ohtani, R Fujii, M Hesse, RL Lysak
PublisherAmerican Geophysical Union
Pages61-70
Number of pages10
Volume118
ISBN (Print)0-87590-976-0
StatePublished - 2000
EventConference on Magnetospheric Current Systems - KONA
Duration: 10 Jan 199915 Jan 1999

Publication series

NameGEOPHYSICAL MONOGRAPH SERIES
PublisherAMER GEOPHYSICAL UNION
Volume118
ISSN (Print)0065-8448

Conference

ConferenceConference on Magnetospheric Current Systems
CityKONA
Period10/01/9915/01/99

    Scopus subject areas

  • Physics and Astronomy(all)

    Research areas

  • NEAR-EARTH MAGNETOTAIL, SOLAR-WIND CONTROL, MAGNETIC-FIELD, QUANTITATIVE MODELS, MAGNETOPAUSE SHAPE, GEOMAGNETIC-FIELD, PRESSURE BALANCE, CURRENT SHEET, SIZE, PARAMETERS

ID: 28042432