Properties of Discrete and Axisymmetric Features in Jupiter's Atmosphere from Observations of Thermal Emission: Recent Updates on the Eve of the Juno Mission Arrival at Jupiter

We have derived the spatial distribution and evolution of key properties of Jupiter's atmosphere through the analysis of imaging and spatially resolved spectroscopy of its thermal emission. These observations and their analysis represent a source of data we plan to acquire as a key component of support for the Juno mission's atmospheric investigation. From thermal imaging and spectroscopy in the 7-25 µm region, we can derive temperatures between 10 and 500 mbar atmospheric pressure, cloud opacities between 500 mbar and 5 bars, the para-H2 fraction near 300 mbar, the 100-400 mbar distributions of ammonia and phosphine, and the distribution of hydrocarbons in the stratosphere (~1 µbar - 10 mbar). Earlier work determined atmospheric properties of Jupiter's Great Red Spot (Fletcher et al. 2010, Icarus 208, 306) and the evolution of the South Equatorial Belt (SEB) fade (whitening) in 2009-2010 (Fletcher et al. 2011 Icarus, 213, 564). We will illustrate recent results from an examination of (1) the revival (re-darkening) of the SEB in 2010-2011, (2) discovery of uniquely dry regions of the atmosphere that are identified with visible "brown barges" typically located at the northern edge of Jupiter's North Equatorial Belt (NEB), (3) vertical structure of stratospheric waves constituting Jupiter's Quadrennial Oscillation (QQO) (Leovy et al. 1991, Nature 354, 380), and (4) previously unsuspected long-term tropospheric thermal waves uncovered in our multi-year program covering well over a Jovian year. Efforts are underway to provide mission-supporting observations using mid-infrared facility and guest instruments at several observatories during the 14-day orbits of the Juno mission, particularly - but not exclusively - the early orbits dedicated to remote sensing observations.