A Comparative Analysis of Jupiter’s Northern Aurora using Juno’s MWR, UVS, and JIRAM Instruments

Abstract

<p>This study continues the work from Hodges et al. (2020) to further analyze microwave emissions associated with Jupiter’s aurorae as seen by the 600 MHz channel of the MicroWave Radiometer (MWR) onboard the Juno spacecraft. The MWR can obtain spatial maps of the northern aurora. These maps allow a two-dimensional comparison of auroral observations at microwave, ultraviolet, and infrared frequencies. Each spectral region provides information on different particles of the auroral plasma. For example, microwave observations provide information on the electron density content and structure. Ultraviolet observations provide insight on the content and morphology of the Lyman series of H and the Lyman, Werner, and Rydberg bands of H­<sub>2</sub>. Lastly, infrared observations provide information on the content and structure of H<sub>3</sub><sup>+</sup> ions.</p><p>            The UltraViolet Spectrograph (UVS) and the Jovian Infrared Auroral Mapper (JIRAM) have higher resolution observations than the MWR (Gladstone et al. 2014; Adriani et al. 2014; Janssen et al. 2017). To compare observations from these three instruments, the UVS and JIRAM observations are convolved with the antenna beam-pattern of the 5x5 patch antenna array for the 600 MHz channel with a half-power beamwidth 20° (Janssen et al. 2017). The convolution allows UVS and JIRAM data to smear and provide a resolution similar to MWR observations. This process facilitates the comparative analysis of microwave, ultraviolet, and infrared observations of Jupiter’s northern aurora. This work reports on the results of the convolved UVS and JIRAM maps compared to MWR observations from previous perijoves.</p>