DocumentCode :
533468
Title :
Interaction of ULF electromagnetic planetary wavy structures with shear flow in the rotating ionosphere
Author :
Aburjania, G.D.
Author_Institution :
I. Vekua Inst. of Appl. Math., Tbilisi State Univ., Tbilisi, Georgia
fYear :
2010
fDate :
27-30 Sept. 2010
Firstpage :
63
Lastpage :
67
Abstract :
The generation and further linear and nonlinear dynamics of planetary electromagnetic ultra-low-frequency internal waves (EULFW) are investigated in the rotating ionosphere in the presence of inhomogeneous zonal wind (shear flow). Planetary EULFW appear as a result of interaction of the ionospheric medium with the spatially inhomogeneous geomagnetic field. An effective linear mechanism responsible for the generation and intensification of large scale EULF waves in the shear flow is found. For shear flows, the operators of the linear problem are not self-adjoint, and therefore the eigen-functions of the problem maybe non-orthogonal and can hardly be studied by the canonical modal approach. Hence it becomes necessary to use the so-called nonmodal mathematical analysis. It has been shown that the shear flow driven wave perturbations effectively extract energy of the shear flow and temporally algebraic increasing own amplitude and energy. Therefore, these perturbations undergo self organization in the form of the nonlinear solitary vortex structures due to nonlinear twisting of the perturbation´s front. Depending on the features of the velocity profiles of the shear flows the nonlinear vortex structures can be either monopole vortices, or dipole vortex, or vortex streets and vortex chains.
Keywords :
eigenvalues and eigenfunctions; geomagnetism; ionospheric electromagnetic wave propagation; shear flow; solitons; wind; ULF electromagnetic planetary wavy structures; canonical modal approach; dipole vortex; effective linear mechanism; eigen-functions; inhomogeneous zonal wind; ionospheric medium; monopole vortices; nonlinear solitary vortex structures; nonlinear twisting; nonmodal mathematical analysis; perturbation front; planetary electromagnetic ultra-low-frequency internal waves; rotating ionosphere; shear flow; spatially inhomogeneous geomagnetic field; velocity profiles; vortex chains; vortex streets; wave perturbations; Cyclones; Earth; Electromagnetics; Equations; Ionosphere; Nonhomogeneous media; Nonlinear dynamical systems;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED), 2010 Xvth International Seminar/Workshop on
Conference_Location :
Tbilisi
Print_ISBN :
978-1-4244-7790-6
Electronic_ISBN :
978-966-02-5654-5
Type :
conf
Filename :
5623928
Link To Document :
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