The dispersion relation of a new electrostatic ion cyclotron (IC) instability of a plasma with a sheared current of the oxygen ions along the magnetic field is investigated analytically and solved by numerical analysis. The considered case corresponds to the upward sheared flow of the oxygen ions in the aurora where the velocity shearing rate of ion current may be larger than the cyclotron frequency of O+ ion. In such a plasma, we found a new instability in the IC frequency range which develops in the sheared flow and can have a growth rate larger than O+ cyclotron frequency. This instability develops jointly with the known IC instability for the uniform current with a growth rate much less than O+ cyclotron frequency

中文翻译：

---

极光中氧离子向上剪切流的离子回旋频率范围内的强不稳定性

解析研究了等离子体的新静电离子回旋 (IC) 不稳定性与氧离子沿磁场的剪切电流的色散关系，并通过数值分析求解。所考虑的情况对应于极光中氧离子的向上剪切流，其中离子流的速度剪切率可能大于 O+ 离子的回旋频率。在这样的等离子体中，我们发现了 IC 频率范围内的一种新的不稳定性，它在剪切流中产生，并且其增长率可能大于 O+ 回旋频率。这种不稳定性与均匀电流的已知 IC 不稳定性共同发展，其增长率远低于 O+ 回旋频率