Near-earth magnetotail shape and size as determined from the magnetopause flaring angle

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/95JA02834· OSTI ID:254436

Petrinec, S M; Russell, C T ^[1]

---

1. Univ. of California, Los Angeles, CA (United States)

Knowledge of the average size and shape of the near-Earth magnetotail is an essential element for our understanding of the magnetospheric response to the influence of the solar wind. An empirical model of the near-Earth magnetotail has been developed, which depends upon distance downtail (x{sub GSM}), the solar wind momentum flux ({rho}v{sup 2}{sub SW}), and the Z{sub GSM} component of the interplanetary magnetic field (IMF B{sub z}). This model has been created by using the pressure balance relation to calculate a set of flare angles for the nightside magnetopause in the region {minus}22 R{sub E} {le}X{sub GSM} {le}{minus}10 R{sub E}. Observations of the magnetic field in the lobe by ISEE 2 and simultaneous observations of the magnetic field and plasma properties of the solar wind by IMP 8 were used to determine the internal and external pressure components, respectively. Examination of calculated flare angle values reveal a dependence upon downtail distance and {rho}v{sup 2}{sub SW}. Normalized to the median downtail distance and dynamic pressure, the angle of flare of the magnetopause is found to increase linearly with decreasing B{sub Z} when the IMF is southward, but there is little variation when the IMF is northward. The empirical function derived for the flaring angle of the magnetotail is used to determine a relation for the radius of the tail. Comparisons with previous empirical models and results are also performed. In addition, values of magnetic flux within the magnetotail are calculated for times of sudden impulse events. 43 refs., 17 figs., 4 tabs.

• OSTI ID: 254436
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A1 Vol. 101; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
INTERPLANETARY MAGNETIC FIELDS
MAGNETOTAIL
SHAPE
SIZE
SOLAR WIND