Dawn‐dusk electric field asymmetry of the Io plasma torus
Dawn‐dusk electric field asymmetry of the Io plasma torus
复制标题
Io 等离子体环面的黎明-黄昏电场不对称性
DOI：
10.1029/gl010i003p00210
复制
发表时间：
1983
影响因子：
5.2
通讯作者：
M. Kivelson
中科院分区：
文献类型：
--
作者：
D. D. Barbosa;M. Kivelson
我们考虑了在木卫一等离子体环上的对流和共转电场的影响。从黎明到黄昏的电场Ec会改变带电粒子的轨道，使它们向黎明移动。受扰轨道所施加的径向漂移意味着低能量离子和电子温度的局部时间依赖性调制，黄昏时比黎明时更热的粒子。当Ec = 4 mV/m时，6 RJ附近的轨道将移动约0.2 RJ。黄昏时的电子温度会比黎明时高20%，这种效应可以解释旅行者紫外光谱仪发现的EUV强度的局部时间不对称性。对流电场的来源是内部的磁层，并归因于尾部逃逸的Iogenic和木星等离子体超越阿尔芬表面。
We consider the effects of a combined convection and corotation electric field across the Io plasma torus. A dawn-to-dusk electric field Ec will modify the orbits of charged particles shifting them toward dawn. The radial drift imposed by the perturbed orbits implies a local time-dependent modulation of low-energy ion and electron temperatures with particles hotter at dusk than at dawn. With Ec ≃ 4 mV/m, the orbits near 6 RJ would be shifted by approximately 0.2 RJ. Then the electron temperature would be 20% higher at dusk than at dawn, an effect which could explain the local time asymmetry of EUV intensity found by the Voyager ultraviolet spectrometer. The source of the convection electric field is internal to the magnetosphere and is attributed to the tailward escape of Iogenic and Jovian plasma beyond the Alfven surface.