Chorus, ECH, and Z mode emissions observed at Jupiter and Saturn and possible electron acceleration
Chorus, ECH, and Z mode emissions observed at Jupiter and Saturn and possible electron acceleration
复制标题
DOI：
10.1029/2012ja018187
复制
发表时间：
2012-12
影响因子：
--
通讯作者：
J. Menietti;Y. Shprits;R. Horne;E. Woodfield;G. Hospodarsky;D. Gurnett
中科院分区：
文献类型：
--
作者：
J. Menietti;Y. Shprits;R. Horne;E. Woodfield;G. Hospodarsky;D. Gurnett
在本文中，我们比较和对比了在木星和土星观测到的合唱、电子回旋谐波（ECH）和Z模发射，并将它们与最近在地球上的电子加速工作联系起来。强烈的合唱发射在磁赤道附近被观察到，可能是源区域，但最强的强度在磁赤道的两侧。木星上的合唱强度通常比土星大一个数量级，木星上的合唱带宽可以达到7或8 kHz (~ 0.6 fc)，而土星上的合唱带宽通常小于2 kHz （~ 0.6 fc）。木星上没有更高纬度的信息；然而，卡西尼号在土星上的高倾角轨道显示，在纬度延伸到30°以上的地方，强烈的合唱强度。在木星上，最初的研究表明，合唱强度足以通过随机过程加速电子；然而，土星上合唱源区域附近的高密度水平表明，除了等离子体注入区域内的局部区域外，效率较低。在木星和土星上，Z模式在电子加速中的作用以及ECH波在俯仰角散射中的作用需要进一步研究。
[1] In this paper we compare and contrast chorus, electron cyclotron harmonics (ECH), and Z mode emissions observed at Jupiter and Saturn and relate them to recent work on electron acceleration at Earth. Intense chorus emissions are observed near the magnetic equator, the likely source region, but the strongest intensities are on either side of the magnetic equator. Chorus intensities at Jupiter are generally about an order of magnitude larger than at Saturn, and the bandwidth of chorus at Jupiter can reach 7 or 8 kHz (∼0.6 fc), while at Saturn it is typically <2 kHz (∼0.6 fc, also). No higher-latitude information is available at Jupiter; however, high inclination orbits at Saturn by Cassini reveal strong chorus intensities at latitudes extending to over 30°. At Jupiter, initial studies reveal the chorus intensities are sufficient to accelerate electrons by a stochastic process; however, the high density levels near the source region of chorus at Saturn indicate a less efficient process except for local regions such as within plasma injection regions. The role of Z mode in electron acceleration and the role of ECH waves in pitch angle scattering at both Jupiter and Saturn require further study.