Journal article
Sub‐Auroral Heating at Jupiter Following a Solar Wind Compression
Geophysical research letters, Vol.52(7), e2024GL113751
04/16/2025
DOI: 10.1029/2024GL113751
Abstract
Jupiter's polar aurorae deliver significant heating at the poles, thought to spread across the planet through atmospheric winds. Additionally, ground‐based Keck observations have revealed a large‐scale high‐temperature region, spatially distinct from the aurorae. Here, we investigate the origins and characteristics of the feature using Keck data, in‐situ Juno spacecraft measurements, and solar wind modeling. Juno exited the magnetosphere on approach to Jupiter, coinciding with modeled high‐speed solar wind impact that compressed the magnetosphere. This hot feature may be dynamic, transported equatorward by winds following auroral activity enhancements from magnetospheric compression akin to a large‐scale traveling ionospheric disturbance on Earth, or driven by the inner magnetosphere particle precipitation. Exploring the dynamic case, we calculated equatorward velocities ranging from 0.46 to 2.02 km , similar to those seen at Earth. Our study underscores the importance of the solar wind at all planets, exemplified by its ability to alter Jupiter's upper‐atmospheric energy balance globally.
Jupiter's powerful aurorae release vast amounts of energy into the planet's upper atmosphere, primarily in the polar regions. Normally, temperatures decrease gradually toward the equator, reflecting how auroral energy is redistributed across the planet. However, a recent discovery revealed a large, high‐temperature region far from the aurorae, disrupting this typical pattern. In this study, data from NASA's Juno spacecraft and solar wind models indicate that strong solar winds likely compressed Jupiter's magnetic field several hours before this hot region appeared. This compression may have intensified auroral heating, driving the hot region away from the auroral zone. Alternatively, the region could have been heated by a yet unknown process. In either case, prior solar wind activity appears to have been the key trigger.
Jupiter's sub‐auroral upper‐atmospheric temperature was seen 200 K elevated in a region measuring 180° longitude by 8° latitude Juno data and solar wind modeling demonstrate that the Jovian magnetosphere was compressed several hours prior by fast solar wind streams The hot feature may drift equatorward from the aurora at 1.1 0.2 km , or be driven by a novel magnetospheric energy source
Details
- Title: Subtitle
- Sub‐Auroral Heating at Jupiter Following a Solar Wind Compression
- Creators
- James O’Donoghue - University of ReadingL. Moore - Boston UniversityH. Melin - Northumbria UniversityT. Stallard - Northumbria UniversityW. S. Kurth - University of IowaM Owens - University of ReadingT. Bhakyapaibul - University of Illinois Urbana-ChampaignC. Tao - National Institute of Information and Communications Technology (NICT) Tokyo JapanJ. E. P. Connerney - Goddard Space Flight CenterK. L. Knowles - Northumbria UniversityH. Kita - Tohoku Institute of TechnologyK. Roberts - Boston UniversityP. I. Tiranti - Northumbria UniversityO. Agiwal - Boston UniversityR. Johnson - Department of Physics Aberystwyth University Aberystwyth UKR. Wang - University of LeicesterE. Thomas - Northumbria UniversityG. Murakami - Japan Aerospace Exploration Agency
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.52(7), e2024GL113751
- DOI
- 10.1029/2024GL113751
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Publisher
- AMER GEOPHYSICAL UNION
- Grant note
- Science and Technology Facilities Council: ST/X003426/1 STFC Ernest Rutherford FellowshipJapanese Space Agency under the International Top Young Fellow programme: 80NSSC23K0661 NASA: ST/W001527/1 STFC James Webb Fellowship: ST/W00089X/1 UK STFC: ST/X508548/2 Roy J. Carver Charitable Trust - STFC Studentship: 80NSSC21K0157 Northumbria University Research Studentship at Northumbria University, UK - NASAUniversity of Leicester Doctoral ScholarshipW.M. Keck Foundation
J.O. was supported by the STFC Ernest Rutherford Fellowship ST/X003426/1 at the University of Reading and the Japanese Space Agency under the International Top Young Fellow programme. L.M. was supported by NASA under Grant NNX17AF14G issued through the Solar System Observations Program and Grant 80NSSC19K0546 issued through the Solar System Workings Program. H.M. was supported by the STFC James Webb Fellowship ST/W001527/1. T.S.S. was supported by UK STFC Consolidated Grant ST/W00089X/1. W.S.K.'s research at the University of Iowa is supported by NASA through Contract 699041X with the Southwest Research Institute. W.S.K. acknowledges the use of the Space Physics Data Repository at the University of Iowa supported by the Roy J. Carver Charitable Trust. P.I.T. was funded by STFC Studentship ST/X508548/2. K.L.K. was supported by a Northumbria University Research Studentship at Northumbria University, UK. O.A. was funded by NASA Grant 80NSSC21K0157 (Solar System Workings Program) and NASA Grant 80NSSC23K0661 (New Frontiers Data Analysis Program). R.W. was supported by a University of Leicester Doctoral Scholarship. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and NASA. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are fortunate to have the opportunity to conduct observations from this mountain. This research was supported by the International Space Science Institute for the international team on "Jupiter's Non-Auroral Ionosphere."
- Language
- English
- Date published
- 04/16/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984808537402771
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