在E区通过非相干散射等离子体线观测的极光场对准电流
Auroral field-aligned currents by incoherent scatter plasma line observations in the E region
摘要：
1999年2月，瑞典-日本EISCAT活动的目的是测量极光弧内外的电离层参数。离子线雷达实验被优化，以尽可能高的速度探测E区和较低的F区。两个额外的通道用于覆盖相同高度的等离子体线测量，总共提供3个上移和3个下移的频带，每个频带为25 kHz。在大多数时间里，移位的频道被调谐到3（两者）、4（向上）、5.5（向下）和6.5（两者）MHz。每当雷达探测漫射极光时，就会看到微弱的信号，这与相对较低的等离子体频率相对应。当极光弧通过雷达波束时，观测到回波功率显著增加。许多情况下，同时向上和向下移动等离子体线的记录。尽管环境相当活跃，但高度优化的测量能够对等离子体线的特性进行研究。一个修正的理论非相干散射光谱被用来解释测量。总的趋势是一个向上的场一致的电流在弥漫的极光，证实了一个完整的组合离子和等离子体线光谱。也有强超热电流的情况下，由信号强度之间的大差异向上和向下移位等离子体线。
英文摘要：
The aim of the Swedish-Japanese EISCAT campaign in February 1999 was to measure the ionospheric parameters inside and outside the auroral arcs. The ion line radar experiment was optimised to probe the E-region and lower F-region with as high a speed as possible. Two extra channels were used for the plasma line measurements covering the same altitudes, giving a total of 3 upshifted and 3 downshifted frequency bands of 25 kHz each. For most of the time the shifted channels were tuned to 3 (both), 4 (up), 5.5 (down) and 6.5 (both) MHz. Weak signals are seen whenever the radar is probing the diffuse aurora, corresponding to the relatively low plasma frequencies. At times when auroral arcs pass the radar beam, significant increases in return power are observed. Many cases with simultaneously up and down shifted plasma lines are recorded. In spite of the rather active environment, the highly optimised measurements enable investigation of the properties of the plasma lines. A modified theoretical incoherent scatter spectrum is used to explain the measurements. The general trend is an upgoing field-aligned current in the diffuse aurora, confirmed with a full fit of the combined ion and plasma line spectra. There are also cases with strong suprathermal currents indicated by large differences in signal strength between up- and downshifted plasma lines.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
