Energetic particle signatures of magnetic field-aligned potentials over Jupiter's polar regions
Energetic particle signatures of magnetic field-aligned potentials over Jupiter's polar regions
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DOI：
10.1002/2017gl074366
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发表时间：
2017-09-16
影响因子：
5.2
通讯作者：
Valek, P.
中科院分区：
文献类型：
--
作者：
Clark, G.;Mauk, B. H.;Valek, P.
美国宇航局的朱诺号航天器首次通过木星极光区的轨道的最新结果没有显示极光或极地区域的相干加速的证据。然而，在这封信中，我们展示了朱诺号木星能量粒子探测器仪器在第三次极光通过期间的高能粒子数据，这些数据显示了木星极地部分地区向下平行电场的确凿证据。高能粒子分布在向下的电流区域中显示出倒V型离子和电子结构，在数百keV到类似于1 MeV的范围内具有加速的峰值分布。这些大的电位结构的起源进行了调查和讨论，在目前的理论框架内的电流-电压关系在地球和木星。平行电场负责加速粒子以维持极光/磁层电路，这似乎是具有导电电离层的强磁化行星中的一种常见现象;然而，其起源和生成机制是正在进行的研究课题。
Recent results of the first ever orbit through Jupiter's auroral region by NASA's Juno spacecraft did not show evidence of coherent acceleration in the auroral or polar region. However, in this letter, we show energetic particle data from Juno's Jupiter Energetic-particle Detector Instrument instrument during the third auroral pass that exhibits conclusive evidence of downward parallel electric fields in portions of Jupiter's polar region. The energetic particle distributions show inverted-V ion and electron structures in a downward electric current region with accelerated peaked distributions in hundreds of keV to similar to 1MeV range. The origin of these large electric potential structures is investigated and discussed within the current theoretical framework of current-voltage relationships at both Earth and Jupiter. Parallel electric fields responsible for accelerating particles to maintain the aurora/magnetospheric circuit appear to be a common phenomenon among strongly magnetized planets with conducting ionospheres; however, their origin and generation mechanisms are subjects of ongoing research.