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Observations and Electron Density Retrievals of Jupiter's Discrete Auroral Arcs Using the Juno Microwave Radiometer
Author(s) -
Hodges Amorée,
Steffes Paul,
Bellotti Amadeo,
Waite J. Hunter,
Brown Shan,
Oyafuso Fabiano,
Orton Glenn,
Arballo John,
Gladstone G. Randall,
Levin Steven,
Bolton Scott
Publication year - 2020
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1029/2019je006293
Subject(s) - jupiter (rocket family) , microwave , microwave radiometer , physics , radiometer , atmosphere (unit) , electron density , flux (metallurgy) , atmosphere of jupiter , electron , astronomy , jovian , atmospheric sciences , astrophysics , planet , materials science , meteorology , optics , space shuttle , quantum mechanics , metallurgy , saturn
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 × 10 9 cm −3 , and in the presence of the Io flux tube, electron densities could reach 10 10 cm −3 affecting Channels 2 and 3.