Lower hybrid drift wave turbulence and associated electron transport coefficients and coherent structures at the magnetopause boundary layer

被引:5
|
作者
Shukla, PK [1 ]
Mamun, AA
机构
[1] Ruhr Univ Bochum, Fak Phys & Astron, Inst Theoret Phys 4, D-44780 Bochum, Germany
[2] Umea Univ, Dept Plasma Phys, S-90187 Umea, Sweden
[3] Jahangirnagar Univ, Dept Phys, Dhaka, Bangladesh
关键词
lower hybrid drift waves; turbulence; magnetopause; boundary layer;
D O I
10.1029/2002JA009374
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
[1] It is well known that at the Earth's magnetopause there is much scale size turbulence whose origin is not yet fully understood. Our objective here is to present a detailed investigation of short-wavelength (in comparison with the ion gyroradius) lower hybrid drift (LHD) wave turbulence that is generated by sheared electron flows and ion beams. We employ here a hybrid approach, in which the ions are treated kinetically while the cold electrons are described by means of a fluid model, and derive the linear dispersion relation. The latter is analyzed analytically and numerically for different realistic situations. Introducing the mixing length hypothesis and mode coupling processes, we deduce the saturated wave spectra for nonthermal LHD wave fluctuations. The latter produce the anomalous resistivity and cross-field particle diffusion in a nonuniform magnetoplasma. It is shown that the nonlinear equations governing the dynamics of weakly interacting LHD waves admit stationary solutions in the form of vortices which can also trap particles and transport them to large distances. The present study is relevant for understanding the properties of nonthermal fluctuations and associated transport processes and coherent vortex structures at the magnetopause current layer.
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页数:8
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