Isis 1 observations at the source of auroral kilometric radiation
Isis 1 observations at the source of auroral kilometric radiation
复制标题
Isis 1 在极光千米辐射源处的观测
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
W. Calvert
中科院分区：
文献类型：
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作者：
R. Benson;W. Calvert
由ISIS 1在源区观测极光千米辐射（AKR）。我们发现，这种辐射是在刚好高于局部截止频率的特殊模式下产生的，并且几乎垂直于磁场。它发生在局部电子密度耗尽时，等离子体频率与回旋加速器频率的比值小于0.2。密度衰减仅限于海拔2000公里以上，AKR频率上限对应于该海拔高度的异常截止频率。从ISIS 1观测到的AKR在夜间极光带上方的经度范围比纬度范围大，强烈的源区最常在2200 LMT和70°不变纬度附近观测到。它与倒V型电子沉淀事件直接相关，电子-波能量转换效率为0.1 ~ 1%。
Observations of auroral kilometric radiation (AKR) are made by ISIS 1 in the source region. The radiation is found to be generated in the extraordinary mode just above the local cut-off frequency and to emanate nearly perpendicular to the magnetic field. It occurs within local depletions of electron density, where the ratio of plasma frequency to cyclotron frequency is less than 0.2. The density depletion is restricted to altitudes above about 2000 km, and the upper AKR frequency limit corresponds to the extraordinary cutoff frequency at this altitude. AKR is observed from ISIS 1 above the nighttime auroral zone over a wider extent in longitude than in latitude with an intense source region observed most often near 2200 LMT and 70° invariant latitude. It is directly related to inverted V electron precipitation events with an electron-to-wave energy conversion efficiency of the order of 0.1 to 1%.