Jupiter's Equatorial Plumes and Hot Spots: Spectral Mapping from Gemini/TEXES and Juno/MWR

We present multiwavelength measurements of the thermal, chemical, and cloud contrasts associated with the visibly dark formations (also known as 5‐μm hot spots) and intervening bright plumes on the boundary between Jupiter's Equatorial Zone (EZ) and North Equatorial Belt (NEB). Observations made by the TEXES 5‐ to 20‐μm spectrometer at the Gemini North Telescope in March 2017 reveal the upper‐tropospheric properties of 12 hot spots, which are directly compared to measurements by Juno using the microwave radiometer (MWR), JIRAM at 5 μm, and JunoCam visible images. MWR and thermal‐infrared spectroscopic results are consistent near 0.7 bar. Mid‐infrared‐derived aerosol opacity is consistent with that inferred from visible‐albedo and 5‐μm opacity maps. Aerosol contrasts, the defining characteristics of the cloudy plumes and aerosol‐depleted hot spots, are not a good proxy for microwave brightness. The hot spots are neither uniformly warmer nor ammonia‐depleted compared to their surroundings at p10 bars, suggesting that the hot spot/plume wave is a relatively shallow feature. Plain Language Summary To date, our only direct measurement of Jupiter's gaseous composition came from the descent of the Galileo probe in 1995. However, the results from Galileo appeared to be biased due to the unusual meteorological conditions of its entry location: a dark, cloud‐free region just north of the equator, known as a hot spot. One of the aims of NASA's Juno mission was to place the findings of the Galileo probe into broader context, which requires a detailed characterization of these equatorial hot spots and their neighboring plumes. We combine (a) data from Juno (microwave observations sounding conditions below the clouds and visible/infrared observations revealing variations in cloud opacity) with (b) observations from amateur observers (to track the hot spots over time) and (c) observations from the