Magnetic mapping and Birkeland currents in the Toffoletto-Hill and Tsyganenko magnetosphere models

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/94JA01377· OSTI ID:166262

Ding, C; Hill, T W ^[1]; Toffoletto, F R ^[2]

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1. Rice Univ., Houston, TX (United States)
2. La Trobe Univ., Victoria (Australia)

The authors investigate the mapping of magnetic flux tubes between the high-latitude ionosphere and the equatorial magnetosphere, using the Toffoletto and Hill theoretical model and the Tsyganenko empirical models. In all models, strong distortion of flux tubes occurs near the magnetopause and in the distant tail. These effects are illustrated for various interplanetary magnetic field directions in the Toffoletto and Hill model and for various Kp values in the Tsyganenko model. The authors calculate the Birkeland current that is actually present in each model (from Ampere`s law), as well as the Birkeland current that would be implied if the model were in magnetostatic equilibrium with isotropic plasma pressure (from the Vasyliunas equation). Comparison of the actual and implied Birkeland currents indicates that no physically significant Birkeland current is included in any of the models tested. Each model contains a {open_quotes}noise{close_quotes} component of Birkeland current that is, however, much smaller in magnitude that the {open_quotes}real{close_quotes} Birkeland currents that remain to be included. 31 refs., 11 figs.

• OSTI ID: 166262
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A9 Vol. 99; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
GEOMAGNETIC FIELD
IONOSPHERE
MAPPING
MATHEMATICAL MODELS