Characterizing Jupiter's Polar Vortices at Mid-Infrared Wavelengths
Abstract
Jupiter's polar regions have long been poorly characterized due to the limitations of the viewing geometries available from both Earth- and space-based observing platforms, which result in very oblique views of the poles. The recent close-up polar views from Juno are therefore the first since Pioneer 11, and they offer a wealth of information about the dynamics and composition of Jupiter's deep atmosphere and cloud morphologies at the poles. However, the observations from Juno do not cover the entire vertical atmosphere, due to its limited instrument complement. Therefore, we provide context for Juno's observations at the poles in order to characterize the distinct thermal signatures of the North and South polar vortices in both the stratosphere and the troposphere. The primary dataset analyzed for this study comes from the Subaru 8-meter Telescope's COoled Mid-Infrared Camera and Spectrometer (COMICS), which observes at wavelengths from 7.8 to 25 μm that are sensitive to the thermal emission from Jupiter's upper atmosphere. The COMICS dataset covers 2005 to 2020, which allows for the investigation of any long-term seasonal variability in the polar vortices, as well as providing data at all latitudes that is contemporaneous with Juno's close approaches from 2017 onward. Previous results showed that zonally-averaged retrieved temperatures of the North polar vortex are colder than the South polar vortex by 1-5 degrees Kelvin, and the rate of zonal-mean temperature decrease is faster in the North polar vortex than in the South polar vortex. This study builds on this previous research by characterizing the differences between the North and South polar vortices in terms of other zonally-averaged retrieved quantities, as well as the appearance of the vortices at all longitudes in the COMICS images.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA076...02B
- Keywords:
-
- 0343 Planetary atmospheres;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 1060 Planetary geochemistry;
- GEOCHEMISTRY;
- 5704 Atmospheres;
- PLANETARY SCIENCES: FLUID PLANETS;
- 6220 Jupiter;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS