The first coordinated observations of mid-latitude E-region quasi-periodic radar echoes and lower thermospheric 557.7-nm airglow
The first coordinated observations of mid-latitude E-region quasi-periodic radar echoes and lower thermospheric 557.7-nm airglow
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DOI：
10.5194/angeo-23-2391-2005
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发表时间：
2005-10
影响因子：
1.9
通讯作者：
T. Ogawa;Y. Otsuka;F. Onoma;K. Shiokawa;M. Yamamoto
中科院分区：
文献类型：
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作者：
T. Ogawa;Y. Otsuka;F. Onoma;K. Shiokawa;M. Yamamoto
本文介绍了2002年8月5日晚在SEEK-2活动期间，在日本滋乐市（34.9° N，136.1° E）上空，在一个共同的体积中，对来自散在E（E s）场对准不规则体（FAI）、OI 557.7 nm气辉和中性风的准周期（QP）雷达回波进行的首次协调观测。90-110公里的QP回波高度比平时低10公里，使我们能够对96公里左右高度的QP回波、气辉强度和中性风进行详细比较。QP回波区的东移与中性风、气辉结构和FAI的运动一致，表明Es层的电动力学基本上受中性大气动力学控制。在QP回波事件期间，回波高度明显上升（下降），与也向东移动的气辉增强（下沉）相协调。这一事实表明，向东移动的增强气辉区包括一个向上（向下）的中性风分量，以提高（降低）负责E s形成的风切变节点的高度。在大约96公里高度的FAI的气辉强度，回波强度和多普勒速度波动的周期从10分钟到1小时，表明这些参数调制与短周期的大气扰动。一些低于100公里高度的QP回波区包含小尺度QP结构，其中存在超过100米/秒的非常强的中性风。最近的观察，理论和模拟QP回波的结果进行了比较。关键词电离层（电离层-大气相互作用;电离层不规则性;中纬度电离层）
We present the first coordinated observations of quasi-periodic (QP) radar echoes from sporadic- E ( E s ) field-aligned irregularities (FAIs), OI 557.7-nm airglow, and neutral winds in a common volume over Shigaraki, Japan (34.9° N, 136.1° E) on the night of 5 August 2002 during the SEEK-2 campaign. QP echo altitudes of 90-110 km were lower than usual by 10 km, enabling us to make a detailed comparison among QP echoes, airglow intensity, and neutral wind at around 96 km altitude. Eastward movement of the QP echo regions is consistent with the motions of neutral winds, airglow structures, and FAIs, suggesting that the electrodynamics of E s -layers is fundamentally controlled by the neutral atmospheric dynamics. During the QP echo event, the echo altitudes clearly went up (down) in harmony with an airglow enhancement (subsidence) that also moved to the east. This fact suggests that the eastward-moving enhanced airglow region included an upward (downward) component of neutral winds to raise (lower) the altitude of the wind-shear node responsible for the E s formation. The airglow intensity, echo intensity, and Doppler velocity of FAIs at around 96 km altitude fluctuated with periods from 10 min to 1h, indicating that these parameters were modulated with short-period atmospheric disturbances. Some QP echo regions below 100km altitude contained small-scale QP structures in which very strong neutral winds exceeding 100 m/s existed. The results are compared with recent observations, theories, and simulations of QP echoes. Keywords. Ionosphere (Ionosphere-atmosphere interactions; Ionospheric irregularities; Mid-latitude ionosphere)