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

Abstract

We present multi-wavelength measurements of the thermal, chemical, and cloud contrasts associated with the visibly dark formations (also known as 5-$\mu$m 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 5-20 $\mu$m 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 $\mu$m, 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-$\mu$m 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 $p<1$ bar. At 0.7 bar, the microwave brightness at the edges of hot spots is comparable to other features within the NEB. Conversely, hot spots are brighter at 1.5 bar, signifying either warm temperatures and/or depleted NH${}_3$ at depth. Temperatures and ammonia are spatially variable within the hot spots, so the precise location of the observations matters to their interpretation. Reflective plumes sometimes have enhanced NH${}_3$, cold temperatures, and elevated aerosol opacity, but each plume appears different. Neither plumes nor hot spots had microwave signatures in channels sensing $p>10$ bars, suggesting that the hot-spot/plume wave is a relatively shallow feature.

50 pages, 16 figures, accepted for publication in JGR-Planets

References in corpus (6)

• Jupiter's Ammonia Distribution Derived from VLA Maps at 3--37 GHz
• Moist Convection and the 2010-2011 Revival of Jupiter's South Equatorial Belt
• Jupiter's North Equatorial Belt expansion and thermal wave activity ahead of Juno's arrival
• Assessing the long-term variability of acetylene and ethane in the stratosphere of Jupiter
• Infrared Characterisation of Jupiter's Equatorial Disturbance Cycle
• Atmospheric waves and dynamics beneath Jupiter's clouds from radiowavelength observations

Cited by in corpus (10)

• Combined magnetic and gravity measurements probe the deep zonal flows of the gas giants
• The Shape of Jupiter and Saturn Based on Atmospheric Dynamics, Radio Occultations and Gravity Measurements
• Mid-Infrared Observations of the Giant Planets
• The aftermath of convective events near Jupiter's fastest prograde jet: implications for clouds, dynamics and vertical wind shear
• The Thermal Structure and Composition of Jupiter's Great Red Spot From JWST/MIRI
• Wind shear and the role of eddy vapor transport in driving water convection on Jupiter
• Jovian Vortex Hunter: a citizen science project to study Jupiter's vortices
• Structure of Jupiter's High-Latitude Storms: Folded Filamentary Regions Revealed by Juno
• Microphysical Model of Jupiter's Great Red Spot Upper Chromophore Haze
• Jupiter's Temperature Structure: A Reassessment of the Voyager Radio Occultation Measurements