Equatorial Nighttime Thermospheric Zonal Wind Jet Response to the Temporal Oscillation of Solar Wind
Equatorial Nighttime Thermospheric Zonal Wind Jet Response to the Temporal Oscillation of Solar Wind
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DOI：
10.1029/2021ja029345
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发表时间：
2021-08
期刊：
影响因子：
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通讯作者：
Kedeng Zhang;Hui Wang;Wenbin Wang
中科院分区：
文献类型：
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作者：
Kedeng Zhang;Hui Wang;Wenbin Wang
这项工作利用热层电离层电动力学大气环流模型模拟和挑战型小型卫星有效载荷观测，研究了赤道热层风急流对行星际磁场 Bz 分量时间振荡的响应。热层风急流形成于纬向风最强的磁赤道地区。 IMF Bz 振荡期间，赤道早晨西风急流和夜间东风急流均减少。夜间赤道东风急流的减速主要以离子阻力为主，粘性力的贡献较小。离子与中性粒子之间的相对运动对西经60-180°和东经107-180°的离子阻力具有主导影响；在其他经度处，相对速度（Δvelocity）和电子密度变化（ΔNe）均占主导地位。此外，磁当地时间20时赤道东风急流的减少，也是由离子曳力驱动的，在270 km以上区域较为显着。赤道西向风急流扰动的产生在所有高度上都受到Δ速度的显着影响，而ΔNe在450公里以下变得重要。
This work investigates the response of the equatorial thermospheric wind jet to the temporal oscillation of the Bz component of the interplanetary magnetic field using Thermosphere Ionosphere Electrodynamics General Circulation Model simulations and CHAllenging Minisatellite Payload observations. The thermospheric wind jet is formed in the magnetic equatorial region with the strongest zonal winds. Both the morning westward jet and the nighttime eastward wind jet at the dip equator decrease during the oscillation periods of IMF Bz. Ion drag dominates the deceleration of the equatorial eastward wind jet in the nighttime, with a minor contribution from the viscous force. The relative motion between the ions and neutrals has a dominant influence on the ion drag at the 60–180°W and 107–180°E geographic longitude; at other longitudes, both relative velocity (∆velocity) and electron density changes (∆Ne) are dominant. Moreover, the decrease in the equatorial eastward wind jet at 20 magnetic local time, which is also driven by ion drag, is significant above 270 km. The generation of the equatorial westward wind jet disturbance is significantly influenced by ∆velocity at all altitudes, whereas ∆Ne becomes important below 450 km.