Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2009

Аннотация: A new kind of magnetohydrodynamic waves is analyzed for a current sheet in the presence of a small normal magnetic field component (Bz) varying along the sheet. For the initial undisturbed state, a simplified model of the current sheet is considered with a Harris-like current density distribution across the sheet. Within the framework of this model, an analytical solution is obtained for the flapping-type wave oscillations and instability, related to the gradient of the normal magnetic field component along the current sheet. The flapping wave frequency is found to be a function of the wave number, which has an asymptotic saturation for large wave numbers. This frequency is pure real in a stable situation for the magnetotail current sheet, when the Bz component increases toward Earth. The current sheet becomes unstable in some regions, where the Bz component decreases locally toward Earth. In the stable region, the "kink"-like wave oscillations are calculated for an initial Gaussian perturbation localized to the center of the current sheet. The flapping wave propagations are analyzed for two cases: (1) the initial perturbation is fixed, and (2) the source is moving toward Earth. In the last case, the Mach cone is obtained for the propagating flapping waves. The source for the flapping waves is associated with the fast plasma flow originated from the reconnection region. Copyright 2009 by the American Geophysical Union.

Журнал: Journal of Geophysical Research: Space Physics

Выпуск журнала: Т. 114, № 3

Номера страниц: 03206

ISSN журнала: 21699402

• Erkaev N.V. (Siberian Federal University)
• Semenov V.S. (Institute of Physics, Saint Petersburg State University)
• Kubyshkin I.V. (Institute of Physics, Saint Petersburg State University)
• Kubyshkina M.V. (Institute of Physics, Saint Petersburg State University)
• Biernat H.K. (Institute of Physics, University of Graz)

• Ядро РИНЦ (eLIBRARY.RU)