Longitudinal structure in electron density at mid-latitudes: upward-propagating tidal effects

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• 作者：Hui Wang ; Kedeng Zhang
• 关键词：Mid ; latitude ionosphere ; Electron density ; Longitudinal variation ; Lower atmospheric tides ; TIEGCM model
• 刊名：Earth, Planets and Space
• 出版年：2017
• 出版时间：December 2017
• 年：2017
• 卷：69
• 期：1
• 全文大小：1788KB
• 刊物类别：Earth Sciences, general; Geology; Geophysics/Geodesy;
• 刊物主题：Earth Sciences, general; Geology; Geophysics/Geodesy;
• 出版者：Springer Berlin Heidelberg
• ISSN：1880-5981
• 卷排序：69

文摘

This work studies the upward-propagating migrating and non-migrating tidal effects from the lower atmosphere on the longitudinal variation of electron density (\(\Delta Ne\)) in both the E and F regions at mid-latitudes during the 2002 March equinox. A total of 12 runs are conducted using the Thermosphere Ionosphere Electrodynamic General Circulation model for theoretical investigation. The \(\Delta Ne\) at altitudes above 200 km is affected by upward-propagating tides, with maximum values attained around 300 km. Migrating tides result in reduced longitudinal differences in the \(\Delta Ne\) over North America and in the Southern Hemisphere, while non-migrating tides induce a wave-4 pattern in both hemispheres. The non-migrating effect is weaker than the migrating effect after penetrating into the F region. The neutral composition (i.e., ratio of atom oxygen to molecular nitrogen) is dominant in regulating the \(\Delta Ne\) in both the migrating (accounting for approximately 64%) and non-migrating (about 60%) tidal penetration processes. The \(\Delta Ne\) caused by the tidal meridional wind (accounting for approximately 70%) is stronger than the tidal zonal wind (about 30%) under both the migrating and non-migrating tidal conditions, except in the Southern Hemisphere under migrating tidal input. This work contributes to our understanding of the mechanisms for the longitudinal modulation of the \(\Delta Ne\) at mid-latitudes.Graphical abstractThis study uses TIEGCM model to investigate tidal effects on the longitudinal variation of ionospheric electron density at March equinox 2002.