High‐latitude currents and their energy exchange with the ionosphere‐thermosphere system
High‐latitude currents and their energy exchange with the ionosphere‐thermosphere system
复制标题
高纬度洋流及其与电离层-热层系统的能量交换
DOI：
10.1029/1999ja000409
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发表时间：
2000
影响因子：
--
通讯作者：
J. Thayer
中科院分区：
文献类型：
--
作者：
J. Thayer
高纬度地区磁层和电离层-热层（IT）系统之间的电能传输包含在两个系统之间产生的电流和电场中。因此，IT系统的电动态状态可以通过调制在该区域流动的电流来影响在任何时候传输的电能的多少。本研究收集了1993 - 1998年Sondrestrom非相干散射雷达1557小时的详细E区测量数据，其中95小时用于确定IT系统内的局部电磁能量传输速率，并评估IT系统在改变这种能量传输中的作用。这些测量被组织为59个增强的电能传递周期，覆盖了所有的宇宙时间，但仅限于Sondrestrom上方磁纬74.2°的区域。在研究的许多事件中发现，由于中性风的存在，信息技术系统起到了减少从磁层转移的净电磁能量的作用。黎明扇区比黄昏扇区平均有更大的被动能量沉积速率。中性风对这一速度的降低在黎明部分也被证明更强。这种增强的调制导致能量传输中的黎明-黄昏不对称不那么明显，但在电磁能量传输速率中仍然很明显。
The transfer of electrical energy at high latitudes between the magnetosphere and ionosphere-thermosphere (IT) system is contained within the resulting currents and electric fields between the two systems. As such, the electrodynamic state of the IT system can influence how much of the electrical energy is transferred at any one time by modulating the currents that flow in the region. For this study, 1557 hours of detailed E region measurements by the Sondrestrom incoherent-scatter radar from 1993 through 1998 were collected, of which 95 hours were used to determine the local electromagnetic energy transfer rates within the IT system and evaluate the role of the IT system in modifying this energy transfer. The measurements have been organized into 59 periods of enhanced electrical energy transfer and cover all universal times but are local to the region above Sondrestrom at 74.2° magnetic latitude. In many of the events studied it was found that the IT system acted to reduce the net electromagnetic energy transferred from the magnetosphere owing to the presence of neutral winds. The dawn sector proved to have on average greater passive energy deposition rates than in the dusk sector. The reduction of this rate by neutral winds also proved stronger in the dawn sector. This enhanced modulation caused the dawn-dusk asymmetry in energy transfer to be less pronounced but still apparent in the electromagnetic energy transfer rate.