NASA/IRTF Near-Infrared Spectroscopy and Imaging of Jupiter in Support of the Juno Mission

Since the arrival of the Juno spacecraft at Jupiter in July 2016, near-infrared spectra and images of Jupiter have been obtained regularly at the NASA/IRTF with the SpeX instrument and its guide camera. Spectral "cubes" covering the planet over 0.7-2.5 μm at a resolving power of 200 together with global near-infrared images from 1.5 to 5.1-μm (1) provide context to the narrow longitudinal swaths obtained by the Microwave Radiometer (MWR) during Juno's close ( 4500 km above the cloud tops) pole-to-pole passes, and (2) extend both spectral and spatial coverage of the visual images obtained by JunoCam and the images and spectra in the 2-5 μm range obtained by Jovian Infrared Auroral Mapper (JIRAM). Good global or near-global coverage has been obtained contemporaneously with Juno remote-sensing measurements during its perijoves 1, 4, 6, 8, 13, and 14, the latter occurring recently on July 16, 2018, providing context to characterize the meteorological environments where MWR-observed clusters of lightning occur. Imagery obtained in the 2.16-μm pressure-induced H₂ absorption band sensitive to aerosols in the upper troposphere have revealed significant changes in Jupiter's major meteorological features, including, in May 2017, the distinct brightening of a discrete arc of haze at the southern end of the north polar hood region and an apparent strengthening of the turbulent wake region northwest of the Great Red Spot. These images also extend our team's two-decade IRTF record of H₂-absorption band imagery of Jupiter's North Equatorial Belt (NEB), to characterize the record of outbreaks and large planetary wave structures observed in this region (14-21 degrees north planetocentric latitude). The power of NEB wave structures derived from harmonic analysis of the 2.16-μm maps obtained during the Juno mission - particularly the most powerful waves present in May and June 2017 and in February, March, and July 2018 - will be presented. Finally, the emergence of a major quasi-periodic disturbance in the Equatorial Zone in mid-2018 and implications for perturbation of the MWR-detected deep equatorial upwelling column of concentrated NH₃ will be described.