Article
Geosciences, Multidisciplinary
J. D. Nichols, F. Allegrini, F. Bagenal, B. Bonfond, G. B. Clark, J. T. Clarke, J. E. P. Connerney, S. W. H. Cowley, R. W. Ebert, G. R. Gladstone, D. Grodent, D. K. Haggerty, B. Mauk, G. S. Orton, G. Provan, R. J. Wilson
Summary: This study compares Hubble Space Telescope observations of Jupiter's FUV auroras with Juno spacecraft observations in the equatorial middle magnetosphere of Jupiter, and shows that bright patches on the auroras are associated with magnetospheric convection and plasma injections.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
D. M. Weigt, C. M. Jackman, D. Moral Pombo, S. V. Badman, C. K. Louis, W. R. Dunn, S. C. McEntee, G. Branduardi-Raymont, D. Grodent, M. F. Vogt, C. Tao, G. R. Gladstone, R. P. Kraft, W. S. Kurth, J. E. P. Connerney
Summary: By studying the X-ray auroral structures in Jupiter's northern auroral regions, we investigate the magnetospheric drivers and their relationship with photon distribution. The results suggest two distinct morphologies of X-ray structures, which are crucial for understanding Jupiter's magnetosphere.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Multidisciplinary Sciences
J. W. Blackman, J. P. Beaulieu, D. P. Bennett, C. Danielski, C. Alard, A. A. Cole, A. Vandorou, C. Ranc, S. K. Terry, A. Bhattacharya, I Bond, E. Bachelet, D. Veras, N. Koshimoto, V Batista, J. B. Marquette
Summary: Studies have shown that remnants of destroyed planets and debris-disk planetesimals can survive the volatile evolution of host stars into white dwarfs, while intact planetary bodies around white dwarfs are rarely detected. This study reports the non-detection of a main-sequence lens star in a microlensing event, revealing a system with a 0.53 ± 0.11 solar mass white dwarf hosting a 1.4 ± 0.3 Jupiter-mass planet in Jupiter-like orbit, supporting the prediction that over half of white dwarfs have Jovian planetary companions.
Article
Astronomy & Astrophysics
F. Allegrini, W. S. Kurth, S. S. Elliott, J. Saur, G. Livadiotis, G. Nicolaou, F. Bagenal, S. Bolton, G. Clark, J. E. P. Connerney, R. W. Ebert, G. R. Gladstone, P. Louarn, B. H. Mauk, D. J. McComas, A. H. Sulaiman, J. R. Szalay, P. W. Valek, R. J. Wilson
Summary: This study investigates the electron partial densities and temperatures in Jupiter's main auroral emission region using data from the Jovian Auroral Distributions Experiment (JADE) on Juno. The results show that electron partial densities and temperatures exhibit consistent trends across different longitudes and hemispheres, with no significant correlation with radial distance.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
A. H. Sulaiman, J. R. Szalay, G. Clark, F. Allegrini, F. Bagenal, M. J. Brennan, J. E. P. Connerney, V. Hue, W. S. Kurth, R. L. Lysak, J. D. Nichols, J. Saur, S. J. Bolton
Summary: Juno's highly inclined orbits provide opportunities to study the magnetic field lines connected to the orbit of Io. Its payload allows for remote-sensing and in-situ measurements of the Io-Jupiter interaction. The study presents the analysis of Alfven Poynting fluxes and field-aligned current densities along field lines connected to Io and its orbit.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Junjie Chen, Binzheng Zhang, Dong Lin, Peter A. Delamere, Zhonghua Yao, Oliver Brambles, Kareem A. Sorathia, Viacheslav G. Merkin, John G. Lyon
Summary: Using physics-based global simulations, we have demonstrated the possible presence of a significant axial asymmetry in the reconnection separator at the Jovian magnetopause. Reconnection occurs at the southern-dusk and northern magnetopause under eastward interplanetary magnetic field (IMF) conditions, and switches to the northern-dusk and southern magnetopause when driven by the westward IMF. The different reconnection positions are associated with the interaction of the IMF with the nearly-dipolar background fields and the dawn-dusk asymmetric, helical, closed lobe magnetic fields.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Y. Xu, Z. H. Yao, B. Zhang, P. A. Delamere, L. C. Ray, W. R. Dunn, S. V. Badman, E. H. Feng, Z. Q. Zheng, S. J. Bolton, D. Grodent, B. Bonfond, Y. Wei
Summary: By using joint observations from Juno and the Hubble Space Telescope, this study statistically investigates the relationship between auroral power and current sheet variations under different solar wind conditions. The researchers found that during global main auroral brightening events, which are closely connected to solar wind compressions, the dawn side current sheet becomes substantially thinner compared to times when a quiet auroral morphology is present. Furthermore, the total current intensity in the current sheet increases under solar wind compression conditions. These findings provide important observational evidence on how magnetospheric dynamics driven by solar wind behavior affect auroral activity, deepening our understanding of the coupling between Jupiter's magnetosphere and ionosphere.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
R. L. Guo, Z. H. Yao, D. Grodent, B. Bonfond, G. Clark, W. R. Dunn, B. Palmaerts, B. H. Mauk, M. F. Vogt, Q. Q. Shi, Y. Wei, J. E. P. Connerney, S. J. Bolton
Summary: By analyzing observations from the Hubble Space Telescope and the Juno spacecraft, this study demonstrates the evolution of a double-auroral arc on the dawnside of Jupiter and suggests that this evolution is likely a result of the non-steady progress of magnetic reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Yash Sarkango, James A. Slavin, Xianzhe Jia, Gina A. DiBraccio, Daniel J. Gershman, John E. P. Connerney, William S. Kurth, George B. Hospodarsky
Summary: Two small ion-inertial scale magnetic flux ropes were identified in the Juno magnetic field measurements in Jupiter's magnetotail. These structures could potentially play a significant role in mass loss through plasmoid ejection in the magnetosphere, highlighting the differences in magnetic reconnection processes between Jupiter and other magnetized planets like Earth and Mercury. Further studies are needed to fully understand the implications of these small-scale flux ropes on Jupiter's magnetospheric dynamics.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Astronomy & Astrophysics
Megan N. Barnett, Fred J. Ciesla
Summary: The study explores the effect of Jupiter's core on the solids it accumulates and suggests that its nitrogen enrichment indicates either formation in a more distant region of the solar nebula or suppressed loss of nitrogen.
ASTROPHYSICAL JOURNAL
(2022)
Article
Geosciences, Multidisciplinary
Dong-Xiao Pan, Zhong-Hua Yao, Harry Manners, William Dunn, Bertrand Bonfond, Denis Grodent, Bin-Zheng Zhang, Rui-Long Guo, Yong Wei
Summary: Large-scale electrical currents and Alfvenic waves are important drivers of planetary aurorae, with Alfvenic wave power potentially playing a significant role in driving Jupiter's aurorae as observed in this study. The correlation between ultralow-frequency waves in the magnetosphere and auroral activity suggests a strong connection between them, providing valuable insights into the mechanisms behind Jovian aurorae.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Astronomy & Astrophysics
Yash Sarkango, James A. Slavin, Xianzhe Jia, Gina A. DiBraccio, George B. Clark, Weijie Sun, Barry H. Mauk, William S. Kurth, George B. Hospodarsky
Summary: We expand on previous observations of magnetic reconnection in Jupiter's magnetosphere by surveying ion-inertial scale plasmoids in the Jovian magnetotail. Our results demonstrate that magnetic reconnection in the Jovian magnetotail occurs at ion scales like in other space environments. Ion-scale plasmoids would need to be released every 0.1 s or less to match the canonical 1 ton/s rate of plasma production due to Io.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Geosciences, Multidisciplinary
Michael H. Wong, Philip S. Marcus, Amy A. Simon, Imke de Pater, Joshua W. Tollefson, Xylar Asay-Davis
Summary: The study found that the circularization of Jupiter's Great Red Spot cannot be explained by changes in the horizontal wind shear of the surrounding environment, but the average wind speeds in the high-speed ring increased by 4%-8% from 2009 to 2020. Changes in the wind field coincided with the South Equatorial Belt Outbreak storms of 2016-2017.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Physics, Fluids & Plasmas
Jiong-Hang Liang, Tian-Xing Hu, D. Wu, Zheng-Mao Sheng
Summary: This paper investigates the important role of exchange-correlation of electrons in warm dense matter and analyzes the excitations of electrostatic waves. It is found that the exchange-correlation effect has a significant influence on the group velocity of electrostatic waves. Moreover, the results obtained from different kinetic theories are compared and the differences among them are discussed.
Article
Astronomy & Astrophysics
K. Haewsantati, B. Bonfond, S. Wannawichian, G. R. Gladstone, V Hue, M. H. Versteeg, T. K. Greathouse, D. Grodent, Z. Yao, W. Dunn, J-C Gerard, R. Giles, J. Kammer, R. Guo, M. F. Vogt
Summary: A systematic analysis of bright spots in Jupiter's polar auroras was conducted, revealing isolated, localized, and transient brightenings in the polar regions. These bright spots exhibit variable emitted power and some show quasiperiodic behavior, reappearing in specific locations within short time intervals. The locations of these bright spots vary between the northern and southern hemispheres, suggesting a complex and dynamic nature of Jupiter's auroral activity.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Enhao Feng, Binzheng Zhang, Zhonghua Yao, Peter A. Delamere, Zhiqi Zheng, William R. Dunn, Sheng-Yi Ye
Summary: It is found that the location of Jupiter's magnetopause is not only influenced by the solar wind and interplanetary magnetic field, but also by internal driving factors such as magnetodisc dynamics. Simulation experiments show that even under constant solar wind/IMF conditions, the magnetopause of Jupiter can exhibit dynamic variations, with a predicted range of up to 50 Jupiter radii. The study reveals that interchange structures in the Jovian magnetodisc can generate significant radial dynamic pressure, leading to significant variations in the magnetopause location. These findings provide important new insights into the understanding of magnetopause location and dynamics, with implications for other systems with internal mass loading and/or rapid rotation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Rohini S. Giles, Vincent Hue, Thomas K. Greathouse, G. Randall Gladstone, Joshua A. Kammer, Maarten H. Versteeg, Bertrand Bonfond, Denis C. Grodent, Jean-Claude Gerard, James A. Sinclair, Scott J. Bolton, Steven M. Levin
Summary: Reflected sunlight observations from the Ultraviolet Spectrograph on the Juno spacecraft revealed significant spatial variability in the distribution of acetylene at Jupiter's south pole. A localized region with enhanced acetylene absorption corresponds to the location of Jupiter's southern polar aurora. This finding highlights the strong influence of charged auroral particles on Jupiter's upper-atmosphere chemistry.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Astronomy & Astrophysics
V. Hue, G. R. Gladstone, C. K. Louis, T. K. Greathouse, B. Bonfond, J. R. Szalay, A. Moirano, R. S. Giles, J. A. Kammer, M. Imai, A. Mura, M. H. Versteeg, G. Clark, J. -c. Gerard, D. C. Grodent, J. Rabia, A. H. Sulaiman, S. J. Bolton, J. E. P. Connerney
Summary: The positions of Jupiter's satellites Io, Europa, and Ganymede vary with time, resulting in changes in the lead angles of their respective auroral footprints. This study provides an empirical model of the equatorial lead angles for the northern and southern hemispheres using spectral images collected by Juno-UVS. The lead angle measurements are used to estimate the travel times of Alfven waves between the three innermost Galilean moons and Jupiter's hemispheres.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
B. H. Mauk, J. R. Szalay, F. Allegrini, F. Bagenal, S. J. Bolton, G. Clark, J. E. P. Connerney, G. R. Gladstone, D. K. Haggerty, P. Kollmann, W. S. Kurth, C. P. Paranicas, A. H. Sulaiman
Summary: By combining multiple ion and electron data sources to diagnose electrostatic potentials both above and below the spacecraft, this study finds that during downward electron broadband events in Zone I, evidence of downward electron electrostatic acceleration can either disappear or endure at some level. Most often, evidence of downward electron electrostatic acceleration is strongly suppressed with strong downward electron broadband acceleration. However, caution must be exercised in these studies as plasmasheet electron precipitation spectra can mimic broadband acceleration spectra.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
G. Clark, J. R. Szalay, A. H. Sulaiman, J. Saur, P. Kollmann, B. H. Mauk, C. Paranicas, V. Hue, T. Greathouse, F. Allegrini, A. Glocer, K. Garcia-Sage, S. Bolton
Summary: This study investigates energetic proton observations associated with Io's footprint tail (FPT) and compares them with in situ measurements of plasma waves and lower-energy electron environments. The results provide further evidence that proton acceleration in Io's FPT is likely caused by wave-particle interactions via electromagnetic ion cyclotron waves generated by precipitating electrons into Jupiter's ionosphere. The analysis also reveals important details about the Io-Jupiter interaction, including the persistence of proton acceleration in Io's FPT, positive correlations between energetic protons and plasma waves and <100 keV/Q electrons, and the presence of fine spatial/temporal structure in a small number of Io FPT crossings.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Astronomy & Astrophysics
James A. Sinclair, Thomas K. Greathouse, Rohini S. Giles, John Lacy, Julianne Moses, Vincent Hue, Denis Grodent, Bertrand Bonfond, Chihiro Tao, Thibault Cavalie, Emma K. Dahl, Glenn S. Orton, Leigh N. Fletcher, Patrick G. J. Irwin
Summary: We used the Gemini-North/Texas Echelon Cross Echelle Spectrograph to observe mid-infrared spectroscopy of Jupiter's mid-to-high latitudes. Our observations capture the auroral emissions and the effects of a solar wind compression, highlighting the interaction between the polar stratosphere and the external space environment. By analyzing the spectra, we found that the brightening of certain emissions is due to upper stratospheric heating, driven by magnetospheric dynamics accelerated by the solar wind enhancement. The south side of Jupiter experiences deeper heating compared to the north, likely due to higher Pedersen conductivities and inhibiting efficient horizontal mixing/advection.
PLANETARY SCIENCE JOURNAL
(2023)
Article
Astronomy & Astrophysics
K. Moreland, M. A. Dayeh, G. Li, A. Farahat, R. W. Ebert, M. I. Desai
Summary: In this study, the effect of different sampling windows on the properties of shocks and energetic storm particles (ESP) was investigated. The results showed that the compression ratios of magnetic field, density, and temperature varied within certain ranges, and the shock speed and shock obliquity also showed variability. The spectral indices of ESP both upstream and downstream of the shock exhibited similarities, suggesting local acceleration at the shock. Additionally, the study found that the derived shock properties were representative within specific time windows, beyond which they no longer held true.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
A. Santa Fe Duenas, R. W. Ebert, M. A. Dayeh, M. I. Desai, L. K. Jian, G. Li
Summary: We examined variations in energetic storm particle (ESP) heavy-ion average intensities and energy spectra between 0.1 and 75 MeV nucleon(-1) for coronal mass ejection (CME)-driven interplanetary shocks. Comparing observations from solar cycles 23 and 24, we found that the number of heavy-ion ESP events was higher during cycle 23 and there were more events at higher energies (>10 MeV nucleon(-1)). This suggests more efficient ESP acceleration during cycle 23.
ASTROPHYSICAL JOURNAL
(2023)
Article
Geosciences, Multidisciplinary
J. D. Nichols, F. Allegrini, F. Bagenal, B. Bonfond, G. B. Clark, J. T. Clarke, J. E. P. Connerney, S. W. H. Cowley, R. W. Ebert, G. R. Gladstone, D. Grodent, D. K. Haggerty, B. Mauk, G. S. Orton, G. Provan, R. J. Wilson
Summary: This study compares Hubble Space Telescope observations of Jupiter's FUV auroras with Juno spacecraft observations in the equatorial middle magnetosphere of Jupiter, and shows that bright patches on the auroras are associated with magnetospheric convection and plasma injections.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Y. Xu, Z. H. Yao, B. Zhang, P. A. Delamere, L. C. Ray, W. R. Dunn, S. V. Badman, E. H. Feng, Z. Q. Zheng, S. J. Bolton, D. Grodent, B. Bonfond, Y. Wei
Summary: By using joint observations from Juno and the Hubble Space Telescope, this study statistically investigates the relationship between auroral power and current sheet variations under different solar wind conditions. The researchers found that during global main auroral brightening events, which are closely connected to solar wind compressions, the dawn side current sheet becomes substantially thinner compared to times when a quiet auroral morphology is present. Furthermore, the total current intensity in the current sheet increases under solar wind compression conditions. These findings provide important observational evidence on how magnetospheric dynamics driven by solar wind behavior affect auroral activity, deepening our understanding of the coupling between Jupiter's magnetosphere and ionosphere.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Wenli Mo, Sarah K. Vines, Robert C. Allen, Caitriona M. Jackman, Chris Paranicas
Summary: Analysis of 2,114 magnetopause crossings at Saturn during the Cassini mission reveals the presence of possible magnetic reconnection and Kelvin-Helmholtz instability at Saturn's magnetopause, suggesting their prevalence in the outer planets. This study provides insight into magnetopause dynamics and plasma transport, contributing to a more comprehensive understanding of outer planets' magnetospheric processes.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
A. Moirano, A. Mura, B. Bonfond, J. E. P. Connerney, V. Dols, D. Grodent, V. Hue, J. C. Gerard, F. Tosi, A. Migliorini, A. Adriani, F. Altieri, C. Castagnoli, A. Cicchetti, B. M. Dinelli, D. Grassi, M. L. Moriconi, R. Noschese, G. Piccioni, C. Plainaki, P. Scarica, G. Sindoni, R. Sordini, D. Turrini, F. Zambon
Summary: One of the features of Jupiter's aurora is the emission caused by the orbital motion of its moon Io. The interaction between Io and the surrounding plasma generates Alfven waves that travel along the magnetic field lines towards Jupiter's ionosphere, causing the production of the Io footprint auroral emission. By studying the position of the Io footprint using JIRAM onboard Juno, researchers can retrieve information on the variability of the Io Plasma Torus and gain insights into the density and temperature variations. The results provide evidence of non-System III variability in the plasma density and temperature, suggesting either local time asymmetry or temporal variability of the torus.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
N. Krupp, E. Roussos, M. Fraenz, P. Kollmann, C. Paranicas, G. Clark, K. Khurana, A. Galli
Summary: The Galileo spacecraft observed particle beams originating from the moon Callisto during its flybys between 1996 and 2001. These beams, predominantly from the North but occasionally from the South, are more likely to be a result of Callisto's magnetospheric interaction rather than independent magnetospheric processes. Energetic particle depletions in Callisto's wake were not observed, but pitch angle distribution revealed a higher field-aligned particle flux within the wake. Outside the wake, disturbance regions were found, potentially related to Alfven-wing structures.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
