Modeling diurnal variations of the IAR parameters

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• 作者：E. N. Fedorov ; N. G. Mazur ; V. A. Pilipenko…
• 关键词：ULF waves ; Geomagnetic pulsations ; Ionospheric Alfvén resonator ; Mode coupling ; Ionosphere monitoring
• 刊名：Acta Geodaetica et Geophysica
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：51
• 期：4
• 页码：597-617
• 全文大小：938 KB
• 刊物主题：Geophysics/Geodesy;
• 出版者：Springer Netherlands
• ISSN：2213-5820
• 卷排序：51

文摘

Characteristic feature of the upper ionosphere is the occurrence of the ionospheric Alfvén resonator (IAR) and MHD waveguide, which can trap the electromagnetic waves in the frequency range from fractions of Hz to few Hz. The proposed numerical model is based on the solution of MHD equations in a realistic ionosphere, whose parameters are reconstructed from the IRI model. We estimated, both analytically and numerically, a critical, wave scale dependent, value of the Hall conductance when a wave equation for an uncoupled Alfvénic mode can be used to estimate the spectral parameters of the IAR. The model has enabled us to compare the contributions into the IAR Q-factor of the Joule dissipation in the lower ionosphere and a wave leakage into the magnetosphere. The first mechanism dominates during daytime, whereas the latter mechanism prevails during nighttime. The ground signatures of IAR can be used for monitoring of the F-layer plasma density and vertical total electron content on the basis of relationships derived from the developed IAR model.