Open magnetopause model of the earth's distant tail based on ISEE 3 evidence

Journal Article · Tue Mar 01 00:00:00 EST 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA093iA03p01795· OSTI ID:5265547

Grzedzielski, S; Macek, W

It is shown that an ''open'' hydromagnetic equilibrium model of the Earth's distant magnetotail can describe the gross features of the cross-tail dimensions, the magnetic field intensity, and the average plasma density in the tail lobes, as measured by ISEE 3. The tail flaring rate changes (decreases) downstream at around Xapprox.-(100--120) R/sub E/. Beyond that distance our model predicts a noncircular flattened tail whose average diameter is 2 R/sub T/ = 2chemically bondyzchemically bond/sup 1/2 = 60--70 R/sub E/ at down-tail distances of Xapprox.-200 R/sub E/ and 2R/sub T/approx.70--110 R/sub E/ at Xapprox.-1000 R/sub E/. These values agree with measurements by ISEE 3 and Pioneer 7, respectively. The degree of flattening yz (east-westnorth-south dimension ratio) is related to the degree of anisotropy of the plama pressure (p/sub parallel/p/sub perpendicular/ ratio) and to the degree of anisotropy of the field pressure in the solar wind. The most probable flattened tail, elongated in the east-west direction, is obtained in our model (for p/sub parallel/p/sub perpendicular/approx.1) with an yz ratio of 1.4--1.7 at Xapprox.-200 R/sub E/ and 7--12 at Xapprox.-1000 R/sub E/. A tail cross section elongated in the north-south direction (yz<1) would require a large p/sub parallel/p/sub perpendicular/ ratio, exceeding the threshold for the excitation of the fire hose instability in the solar wind

• Research Organization: Space Research Center, Polish Academy of Sciences, Warsaw
• OSTI ID: 5265547
• Journal Information: J. Geophys. Res.; (United States), Vol. 93:A3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAGNETOTAIL
MAGNETOPAUSE
DISTRIBUTION FUNCTIONS
EARTH MAGNETOSPHERE
INTERPLANETARY MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
PLASMA DENSITY
PLASMA PRESSURE
SOLAR WIND
EARTH ATMOSPHERE
FLUID MECHANICS
FUNCTIONS
HYDRODYNAMICS
MAGNETIC FIELDS
MECHANICS
SOLAR ACTIVITY
640201* - Atmospheric Physics- Auroral
Ionospheric
&amp; Magetospheric Phenomena