We present Jovian electron densities measured by the Juno Waves instrument at high-latitudes (with magnetic latitudes of on magnetic field lines threading the Io torus and plasma sheet (with M-shells of ) using the first 29 orbits of the Juno mission. We infer electron densities from characteristic frequency cutoffs and resonances in plasma wave spectra. Often more than one of the characteristic frequencies of the plasma can be identified, whose consistency provides credibility to the plasma density estimates. The majority of density measurements are on magnetic field lines threading the Io torus and intersecting Jupiter's ionosphere between Io's M-shell and the auroral main oval, but there is evidence of density dropouts near and poleward of the auroral oval, which may be important in auroral particle acceleration. Sharp density gradients are found near field lines mapping to the inner edge of the Io torus M-shells. These observations demonstrate the extension of elevated Io torus densities along field lines to higher latitudes.

中文翻译：

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木星 Io 环面的高纬度延伸：朱诺波测量的电子密度

我们展示了由朱诺波仪器在高纬度地区测量的木星电子密度（在穿过 Io 环面和等离子层的磁力线上的磁纬度（具有 M 壳层）) 使用朱诺号任务的前 29 个轨道。我们从等离子波谱中的特征频率截止和共振推断电子密度。通常可以识别多个等离子体的特征频率，其一致性为等离子体密度估计提供可信度。大多数密度测量是在穿过 Io 环面并与 Io 的 M 壳层和极光主椭圆之间的木星电离层相交的磁场线上进行的，但有证据表明极光椭圆附近和极地的密度下降，这可能在极光中很重要粒子加速度。在映射到 Io torus M 壳内边缘的场线附近发现了尖锐的密度梯度。这些观察结果表明升高的 Io 环面密度沿场线扩展到更高的纬度。