Тип публикации: статья из журнала
Год издания: 2012
Идентификатор DOI: 10.1063/1.4725506
Ключевые слова: Current sheets, Decreasing functions, Discrete approximation, Earth's magnetotail, Equilibrium conditions, Gradient theory, Hamiltonian formulations, Ionospheric conductivity, Magnetic filaments, Magnetic flux tube, Magnetic perturbation, Magnetic tube, Stiff equations, System of ordinary differential equations, Boundary conditions, Magnetic fields, Magnetic structure, Ordinary differential equations, Sun, Tubes (components)
Аннотация: Magnetic filament approach is applied for modeling of nonlinear "kink"-like flapping oscillations of thin magnetic flux tubes in the Earth's magnetotail current sheet. A discrete approximation for the magnetic flux tube was derived on a basis of the Hamiltonian formulation of the problem. The obtained system of ordinary differentiaПоказать полностьюl equations was integrated by method of Rosenbrock, which is suitable for stiff equations. The two-dimensional exact Kan's solution of the Vlasov equations was used to set the background equilibrium conditions for magnetic field and plasma. Boundary conditions for the magnetic filament were found to be dependent on the ratio of the ionospheric conductivity and the Alfven conductivity of the magnetic tube. It was shown that an enhancement of this ratio leads to the corresponding increase of the frequency of the flapping oscillations. For some special case of boundary conditions, when the magnetic perturbations vanish at the boundaries, the calculated frequency of the "kink"-like flapping oscillations is rather close to that predicted by the "double gradient" analytical model. For others cases, the obtained frequency of the flapping oscillations is somewhat larger than that from the "double gradient" theory. The frequency of the nonlinear flapping oscillations was found to be a decreasing function of the amplitude. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4725506]
Журнал: PHYSICS OF PLASMAS
Выпуск журнала: Vol. 19, Is. 6
ISSN журнала: 1070664X
Место издания: MELVILLE
Издатель: AMER INST PHYSICS