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Alfven Waves in the Solar Wind, Magnetosheath, and Outer MagnetosphereAlfven waves Propagating outward from the Sun are ubiquitous in the solar wind and play a major role in the solar wind-magnetosphere interaction. The passage of the waves generally occurs in the form of a series of discrete steepened discontinuities, each of which results in an abrupt change in the interplanetary magnetic field direction. Some orientations of the magnetic field permit particles energized at the Earth's bow shock to gain access to the foreshock region immediately upstream from the Earth's bow shock. The thermal pressure associated with these particles can greatly perturb solar wind plasma and magnetic field parameters shortly prior to their interaction with the Earth's bow shock and magnetosphere. The corresponding dynamic pressure variations batter the magnetosphere, driving magnetopause motion and transient compressions of the magnetospheric magnetic field. Alfven waves transmit information concerning the dynamic pressure variations applied to the magnetosphere to the ionosphere, where they generate the traveling convection vortices (TCVs) seen in high-latitude ground magnetograms. Finally, the sense of Alfvenic perturbations transmitted into the magnetosheath reverses across local noon because magnetosheath magnetic field lines drape against the magnetopause. The corresponding change in velocity perturbations must apply a weak torque to the Earth's magnetosphere.
Document ID
20070005042
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Sibeck, D. G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2007
Subject Category
Solar Physics
Meeting Information
Meeting: 2006 Huntsville Workshop Outstanding Problems in Geospace Connections Modeling
Location: Huntsville, TN
Country: United States
Start Date: October 2, 2006
End Date: October 6, 2006
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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