Dynamics of the Tongue of Ionizations During the Geomagnetic Storm on 7 September 2015: The Altitudinal Dependences
Dynamics of the Tongue of Ionizations During the Geomagnetic Storm on 7 September 2015: The Altitudinal Dependences
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DOI：
10.1029/2023ja031735
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发表时间：
2023-11
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影响因子：
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通讯作者：
Kedeng Zhang;Huimin Song;Hui Wang;Jing Liu;Wenbin Wang;X. Wan;Dedong Wang;Yaqi Jin
中科院分区：
文献类型：
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作者：
Kedeng Zhang;Huimin Song;Hui Wang;Jing Liu;Wenbin Wang;X. Wan;Dedong Wang;Yaqi Jin
使用来自国防气象卫星计划的电子密度（Ne）观测值，以及气象学、电离层和气候使命星座观测系统和来自热层电离层电动环流模式的模拟。摘要研究了磁暴期间不同高度的极区电离舌（TOI）从双结构到单结构的动态演化。模拟的Ne描绘了在300 km以上的高度分别发生双TOI和单TOI。行星际磁场Bz北转期间，下午TOI消失，上午TOI减小。中性风和双极扩散导致的等离子体输送促进（阻止）了300（500）km处TOI的等离子体密度的衰减，相对贡献分别为42.8%和28.6%（−15.4%和−76.9%）。向下的E × B漂移导致了低/高电离层中暴增强密度区等离子体密度的增强/减小。在IMF By向黄昏转向过程中，早晨TOI主要由反向阳等离子体漂移贡献（300 km处75.8%，500 km处100%），其中纬向分量的贡献相对强于纬向E × B漂移的贡献。E × B向上漂移在上/下电离层中是重要的/可忽略的。中性风和双极扩散都间接地导致了300 km处TOI的等离子体密度的积累（24.2%），而在500 km处，它们的作用较小。
Using the electron density (Ne) observations from the Defense Meteorological Satellite Program, and Constellation Observing Systems for Meteorology, Ionosphere, and Climate mission and simulations from the Thermosphere Ionosphere Electrodynamic General Circulation Model. we investigate the dynamic evolution of the polar tongue of ionization (TOI) from double to single structures at different altitudes during a geomagnetic storm. The modeled Ne depicted that double and single TOIs occurred at altitudes above 300 km, respectively. During the northward turning of interplanetary magnetic field (IMF) Bz, the afternoon TOI disappeared and the morning TOI was reduced. The plasma transport due to neutral winds and ambipolar diffusion facilitated (prevented) the depletion of plasma density of the morning TOI at 300 (500) km, with a relative contribution of 42.8% and 28.6% (−15.4% and −76.9%), respectively. Downward E × B drifts led to an enhancement/reduction of plasma density in the storm enhanced density region in the lower/upper ionosphere. During the duskward turning of IMF By, the morning TOI could be mostly attributed to the anti‐sunward plasma drifts (75.8% at 300 km, 100% at 500 km), with a relatively stronger role of the zonal component than that of meridional E × B drifts. The upward E × B drifts were important/ignorable in the upper/lower ionosphere. Both the neutral winds and ambipolar diffusion resulted in an accumulation of plasma density of the morning TOI at 300 km indirectly (24.2%), however, their roles were minor at 500 km.