Detection of a Warm Thermal Anomaly in Jupiter's Stratosphere
Résumé
We present 3-dimensional thermal mapping results of Jupiter's stratosphere between atmospheric pressures of 30 and 0.01 mbar. By scan-mapping Jupiter with TEXES (the Texas Echelon cross-dispersed Echelle Spectrograph) mounted on the 3-m NASA Infrared Telescope Facility atop Maunakea, we measure methane (CH<SUB>4</SUB>) emission features across Jupiter with complete zonal coverage and meridional coverage between 40° South and 40° North planetocentric latitude. Since methane is well mixed in Jupiter's stratosphere, variations of the methane emission in the CH<SUB>4</SUB> nu<SUB>4</SUB> vibrational band at 8 mum are caused by variations in the atmospheric temperature. Line-by-line radiative transfer modeling of these thermal emission maps reveal a large scale ( 15° in latitude and 30° in longitude) thermal anomaly reaching 15 K above ambient centered at 28°N latitude and 176° W longitude (System III) at a pressure of 1.2 mbar. A map retrieved a week later shows how this anomaly moved and evolved. We will present the observations, radiative-transfer modeling results, and analysis of the thermal anomaly and its evolution.