Observations and Electron Density Retrievals of Jupiter's Discrete Auroral Arcs Using the Juno Microwave Radiometer
Observations and Electron Density Retrievals of Jupiter's Discrete Auroral Arcs Using the Juno Microwave Radiometer
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使用朱诺微波辐射计对木星离散极光弧进行观测和电子密度反演
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发表时间：
2020
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通讯作者：
S. Bolton
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作者：
A. Hodges;P. Steffes;A. Bellotti;J. Waite;Shannon T. Brown;F. Oyafuso;G. Orton;J. Arballo;G. Gladstone;S. Levin;S. Bolton
由于极光等离子体中电子密度增加的区域，木星的极光反射了从木星大气层向上发射的微波辐射，以及从上方寒冷的天空向下发射的微波辐射。朱诺号微波辐射计（MWR）在七个不同轨道上飞越极光时观察到大气层缺乏热辐射。在朱诺号的前 21 条轨道中，有 7 条轨道推断出木星极光弧中的电子密度增强。微波发射最严重的破坏发生在近木星 5 期间。该近木星表现出通道 1 (0.6GHz) 最显着的冷点，通道 2 (1.25GHz) 和通道 3 (2.6GHz) 中也存在冷点，该位置受到木星卫星 Io 的影响，可能增加了木星极光中的电子密度。从通道 1 检索到的最大电子密度约为 3 × 109 cm−3，在 Io 通量管存在的情况下，电子密度可能达到 1010 cm−3，影响通道 2 和通道 3。
Jupiter's aurorae reflect microwave radiation emitted upward from Jupiter's atmosphere and downward from the cold sky above due to regions in the auroral plasma with increased electron densities. The lack of thermal radiation from the atmosphere was observed by Juno's Microwave Radiometer (MWR) on overflights of the aurorae during seven different orbits. Out of Juno's first 21 orbits, seven orbits inferred enhanced electron densities in Jupiter's auroral arcs. The most profound disruption in microwave emission was observed during Perijove 5. This perijove demonstrated the most significant cold spot for Channel 1 (0.6 GHz), with cold spots also present in Channels 2 (1.25 GHz) and 3 (2.6 GHz) in a location where the influence of Jupiter's moon, Io, likely increased the electron density in Jupiter's aurora. The maximum electron densities retrieved from Channel 1 are on the order of 3 × 109 cm−3, and in the presence of the Io flux tube, electron densities could reach 1010 cm−3 affecting Channels 2 and 3.