EGU24-6795, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-6795
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Probing the Depths of Spatial and Temporal Variability in Jupiter from Juno Microwave Radiometer Observations

Glenn Orton1, Zhimeng Zhang2, Steven Levin1, Leigh Fletcher3, Fabiano Oyafuso1, Cheng Li4, Shawn Brueshaber5, Michael H. Wong6, Thomas Momary1, Scott Bolton7, Kevin Baines1, Emma Dahl1, and James Sinclair1
Glenn Orton et al.
  • 1Jet Propulsion Laboratory, MS 183-501, Pasadena, CA, United States of America (glenn.orton@jpl.nasa.gov)
  • 2California Institute of Technology, Pasadena, CA, United States of America
  • 3Universiti of Leicester, Leicester, United Kingdom
  • 4University of Michigan, Ann Arbor, MI, United States of America
  • 5Michigan Technological University, Houghton, MI, United States of America
  • 6SETI Institute, Palo Alto, CA, United States of America
  • 7Southwest Reserach Institute, San Antonnio, TX, United States of America

    Juno’s Microwave Radiometer (MWR) is providing the unprecedented opportunity to explore the dynamical properties and composition of Jupiter’s deep atmosphere, which is arguably one of the most visibly heterogeneous and time variable in the solar system. Since its arrival on 27 August 2016, the MWR has observed variability in microwave emission at wavelengths between 1.3 and 50 cm, sensing from 0.7 bar to over 100 bars of atmospheric pressure at over 57 close approaches to the atmosphere, known as “perijoves”. There has been a concerted effort to collect contextual information from other Juno instruments, as well as ground- and space-based observations to help interpret the MWR results. The space-based observations have included those from Juno’s own visible camera (JunoCam) and its Jupiter Infrared Auroral Mapper (JIRAM), as well as the Hubble Space Telescope (HST). The ground-based observations have included images and spectra from both professional and citizen-science astronomers.

     We report here observations that are constrained to spatial resolutions of 2 degrees in latitude or better, and have been subject to recent improvements in the calibration drift for all MWR’s channels with an improved relative calibration uncertainty of 0.5% or better over the entire mission.  This has allowed us to evaluate zonal-mean temperatures and variability with improved confidence that these are real and not an artifact of receiver drift. The region that by far shows the greatest variability from a zonal mean is the North Equatorial Belt, (NEB: 12oN-16oN planetocentric) with a 2% standard deviation from the mean at all levels sensed by the MWR except for the 50-cm channel that senses variability in temperature and ammonia and water composition at pressures in excess of 100 bars of pressure. Among the strongest variability associated with discrete features in the atmosphere is a major upwelling and subsequent clearing of cloud cover in the North Temperate Belt (NTB: 20oN-26oN) in August-September of 2020.  In general, the microwave antenna temperature variability often but not always correlates with visible or near- to mid-infrared variability. In some regions, such as the Equatorial Zone (EZ: 3oS-6oN), substantial variability is detected not only in regions above the level of the water-condensate cloud (~10 bars) but also at great depth (>100 bars). An important part of our next steps will be to examine where variabilities in the zonal-mean microwave brightness are the result of zonally discrete features in the atmosphere, particularly the NEB.

How to cite: Orton, G., Zhang, Z., Levin, S., Fletcher, L., Oyafuso, F., Li, C., Brueshaber, S., Wong, M. H., Momary, T., Bolton, S., Baines, K., Dahl, E., and Sinclair, J.: Probing the Depths of Spatial and Temporal Variability in Jupiter from Juno Microwave Radiometer Observations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6795, https://doi.org/10.5194/egusphere-egu24-6795, 2024.