Coordinated observations of nighttime medium‐scale traveling ionospheric disturbances in 630‐nm airglow and HF radar echoes at midlatitudes
Coordinated observations of nighttime medium‐scale traveling ionospheric disturbances in 630‐nm airglow and HF radar echoes at midlatitudes
复制标题
中纬度地区 630 nm 气辉和高频雷达回波夜间中尺度移动电离层扰动的协调观测
DOI：
10.1029/2008ja013963
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发表时间：
2009
影响因子：
--
通讯作者：
B. Shevtsov
中科院分区：
文献类型：
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作者：
Shin‐ichi Suzuki;K. Hosokawa;Y. Otsuka;K. Shiokawa;T. Ogawa;N. Nishitani;T. Shibata;A. Koustov;B. Shevtsov
[1]我们使用位于日本北海道（43.5°N，143.6°E）的SuperDARN高频雷达和位于俄罗斯帕拉通卡（53.0°N，158.2°E）的OI 630 nm气辉成像仪，在雷达视场内研究夜间中等尺度的电离层移动扰动（MSTIDS）。2007年12月8日，成像仪识别出向西南传播的MSTID，水平波长为300公里。在整个事件中，雷达连续探测到源自F区高度的十米级场向不规则体（FAI）的电离层回波。这些回波的多普勒速度表现出系统的极性变化，这是一致的气辉强度的变化。这些极性变化将归因于嵌入MSTID中的极化电场引起的E x B等离子体漂移。FAI回波功率也随气辉强度变化而变化：强（弱）回波与气辉耗尽（增强）区域一致。考虑到MSTID极化电场，我们认为观察到的FAI是由F区底侧的梯度漂移不稳定性产生的。
[1] We investigate nighttime medium-scale traveling ionospheric disturbances (MSTIDs) using the SuperDARN HF radar at Hokkaido, Japan (43.5°N, 143.6°E), and an OI 630-nm airglow imager located at Paratunka, Russia (53.0°N, 158.2°E), within the radar field of view. The imager identified southwestward propagating MSTIDs with a horizontal wavelength of ∼300 km on 8 December 2007. Throughout this event, the radar continuously detected ionospheric echoes originating from decameter-scale field-aligned irregularities (FAIs) at the F region heights. The Doppler velocities of these echoes showed systematic polarity changes which were consistent with airglow intensity variations. These polarity changes would be attributed to E x B plasma drifts caused by the polarization electric field embedded in the MSTIDs. The FAI echo powers also varied in agreement with the airglow intensity variations: strong (weak) echoes coincided with the airglow depletion (enhancement) region. Considering the MSTID polarization electric field, it is suggested that the observed FAIs were generated by the gradient drift instability on the bottomside of the F region.