Auroral emissions have been extensively observed at the Earth, Jupiter, and Saturn. These planets all have appreciable atmospheres and strong magnetic fields, and their auroras predominantly originate from a region encircling each magnetic pole. However, Jupiter’s auroras poleward of these “main” emissions are brighter and more dynamic, and the drivers responsible for much of these mysterious polar auroras have eluded identification to date. We propose that part of the solution may stem from Jupiter’s stronger magnetic field. We model large-scale Alfvénic perturbations propagating through the polar magnetosphere toward Jupiter, showing that the resulting <0.1° deflections of the magnetic field closest to the planet could trigger magnetic reconnection as near as ∼0.2 Jupiter radii above the cloud tops. At Earth and Saturn this physics should be negligible, but reconnection electric field strengths above Jupiter’s poles can approach ∼1 V m⁻¹, typical of the solar corona. We suggest this near-planet reconnection could generate beams of high-energy electrons capable of explaining some of Jupiter’s polar auroras.

中文翻译：

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行星附近的磁重联可能是木星神秘极地极光的驱动因素

已在地球、木星和土星上广泛观察到极光辐射。这些行星都有可观的大气层和强大的磁场，它们的极光主要来自环绕每个磁极的区域。然而，木星的极光在这些“主要”排放物的两极更亮、更有活力，而导致这些神秘极地极光中的大部分的驱动因素迄今仍未被识别。我们建议部分解决方案可能源于木星更强的磁场。我们模拟了通过极地磁层向木星传播的大规模阿尔芬微扰动，表明由此产生的最靠近行星的磁场偏转 <0.1° 可以在云顶上方接近 0.2 倍木星半径处触发磁重联。^-1，典型的日冕。我们认为这种近地行星的重联可以产生高能电子束，能够解释木星的一些极地极光。