A Statistical Study of Ion Upflow during Periods of Dawnside Auroral Polarization Streams and Subauroral Polarization Streams
A Statistical Study of Ion Upflow during Periods of Dawnside Auroral Polarization Streams and Subauroral Polarization Streams
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DOI：
10.3390/rs15051320
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
Chengyu Qian;Hui Wang
中科院分区：
文献类型：
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作者：
Chengyu Qian;Hui Wang
利用美国国防气象卫星计划（DMSP）4年的观测资料，研究了黎明亚极光偏振流（SAPS）和黎明极光偏振流（DAPS）对北方半球电离层离子上升流的影响。DAPS的发生率高于SAPS。在DAPS区周围的顶侧电离层中出现了明显的离子上升流。当地磁活动增强时，向阳面SAPS对垂直气流的影响减弱。DAPS附近有显著的上升流通量，而SAPS附近的上升流通量不显著。SAPS期间的等离子体密度谷随着磁活动的增加而变浅。这些变化与磁活动可能是由于削弱离子中性碰撞加热效率在高度扰动的时期。在~800 km高度的DAPS区周围没有明显的等离子体密度谷和离子温度降。SAPS区周围的离子温度降低，而DAPS和SAPS区周围的电子温度升高。
We have investigated the effect of the dawnside subauroral polarization stream (SAPS) and dawnside auroral polarization stream (DAPS) on the ionospheric ion upflow in the Northern Hemisphere by using four years of Defense Meteorological Satellite Program (DMSP) observations. The occurrence rate of DAPS is higher than that of dawnside SAPS. Obvious ion upflow occurs in the topside ionosphere around the DAPS region. The effect of the dawnside SAPS on the vertical flow is weakened when geomagnetic activity increases. There are prominent upflow fluxes around the DAPS, while there are insignificant upflow fluxes around the SAPS region. The plasma density trough during SAPS periods becomes shallower with increasing magnetic activity. These variations with magnetic activity might be due to the weakened ion-neutral collision heating efficiency during highly disturbed periods. There is no obvious plasma density trough or ion temperature drop around the DAPS region at the altitude of ~800 km. The ion temperature around the SAPS area decreases, while the electron temperature increases around the DAPS and SAPS regions.