Ebert R W, Greathouse T K, Clark G, Allegrini F, Bagenal F, Bolton S J, Connerney J E P, Gladstone G R, Imai M, Hue V, Kurth W S, Levin S, Louarn P, Mauk B H, McComas D J, Paranicas C, Szalay J R, Thomsen M F, Valek P W, Wilson R J
Southwest Research Institute San Antonio TX USA.
Department of Physics and Astronomy University of Texas at San Antonio San Antonio TX USA.
Geophys Res Lett. 2019 Jan 16;46(1):19-27. doi: 10.1029/2018GL081129. Epub 2019 Jan 8.
We compare electron and UV observations mapping to the same location in Jupiter's northern polar region, poleward of the main aurora, during Juno perijove 5. Simultaneous peaks in UV brightness and electron energy flux are identified when observations map to the same location at the same time. The downward energy flux during these simultaneous observations was not sufficient to generate the observed UV brightness; the upward energy flux was. We propose that the primary acceleration region is below Juno's altitude, from which the more intense upward electrons originate. For the complete interval, the UV brightness peaked at ~240 kilorayleigh (kR); the downward and upward energy fluxes peaked at 60 and 700 mW/m, respectively. Increased downward energy fluxes are associated with increased contributions from tens of keV electrons. These observations provide evidence that bidirectional electron beams with broad energy distributions can produce tens to hundreds of kilorayleigh polar UV emissions.
我们比较了在“朱诺”号第5次近木点飞越期间，木星北极地区主极光向极地方向同一位置的电子和紫外线观测结果。当观测在同一时间映射到同一位置时，紫外线亮度和电子能量通量同时出现峰值。在这些同步观测期间，向下的能量通量不足以产生观测到的紫外线亮度；而向上的能量通量则足够。我们提出，主要加速区域在“朱诺”号的高度以下，更强的向上电子由此起源。在整个时间段内，紫外线亮度在约240千雷利（kR）处达到峰值；向下和向上的能量通量分别在60和700毫瓦/平方米处达到峰值。向下能量通量的增加与数十千电子伏特电子的贡献增加有关。这些观测结果证明，具有广泛能量分布的双向电子束可以产生数十至数百千雷利的极地紫外线发射。
