Article
Geosciences, Multidisciplinary
R. Wang, I. Y. Vasko, A. Artemyev, L. C. Holley, S. R. Kamaletdinov, A. Lotekar, F. S. Mozer
Summary: This study presents the first observations of electrostatic solitary waves with negative electrostatic potential around a fast plasma flow in the Earth's plasma sheet. The solitary waves are identified as ion holes generated by ion-streaming instabilities and can propagate oblique to local magnetic field.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Aerospace
G. S. Lakhina, S. Singh, R. Rubia
Summary: Electrostatic solitary waves (ESWs) have been observed in the reconnection jet region in Earth's magnetotail, with a proposed mechanism involving ion-acoustic solitons. A model based on observations predicts four types of ion-acoustic solitons with characteristics such as bipolar electric fields and positive potentials, which are in good agreement with the observed ESWs in the reconnection jet region.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Astronomy & Astrophysics
D. A. Patthoff, R. T. Pappalardo, M. Golombek, H. Chilton, E. Crow-Willard, P. C. Thomas
Summary: Several large ridges on Saturn's icy moon Enceladus suggest that they may have been formed through processes similar to those on terrestrial planets. The ridges are possibly thrust blocks and show signs of recent high heat flow.
Article
Physics, Multidisciplinary
I. S. Elkamash, A. M. El-Hanbaly
Summary: This study investigates the existence and propagation features of fully nonlinear electrostatic solitary waves in a three-component plasma using a hydrodynamic model. The effects of plasma configurations on the properties of electrostatic solitary pulse profile are determined, providing insights for better interpretation of localized structures in astrophysical and laboratory plasmas.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Astronomy & Astrophysics
K. Dapre, J. C. E. Irving
Summary: This study investigates the effects of ice shell and ocean thickness, as well as core structure and composition, on the waveforms recorded by a single seismometer for three 1D models of Enceladus. The results suggest that core-transmitted and -reflected phases can be observed even at low epicentral distances, providing constraints on ocean depth and core structure.
Article
Geosciences, Multidisciplinary
I. Y. Vasko, F. S. Mozer, S. D. Bale, A. Artemyev
Summary: This study presents an analysis of electrostatic waves observed near the quasi-perpendicular Earth's bow shock by the Magnetospheric Multiscale spacecraft. The analysis reveals that these electrostatic waves have large amplitudes and can propagate almost perpendicular to the local magnetic field. The results suggest that these waves may strongly affect the dynamics of electrons in collisionless shocks.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Daniele Durante, Tristan Guillot, Luciano Iess, David J. Stevenson, Christopher R. Mankovich, Steve Markham, Eli Galanti, Yohai Kaspi, Marco Zannoni, Luis Gomez Casajus, Giacomo Lari, Marzia Parisi, Dustin R. Buccino, Ryan S. Park, Scott J. Bolton
Summary: The Juno spacecraft has provided new evidence of the gravity field features of Jupiter, which are perturbed by the planet's normal modes. These findings could potentially lead to further exploration of the gas giant's interior structure through measurements of time-variable gravity or onboard observations of normal modes.
NATURE COMMUNICATIONS
(2022)
Article
Astronomy & Astrophysics
Kuldeep Singh, Michael McKerr, Ioannis Kourakis
Summary: Motivated by observations in Saturn's magnetosphere, this study investigates the evolution of modulated electrostatic wavepackets in a dusty plasma environment. Results show that the modulational instability properties are influenced by the dust charge and concentration as well as the presence of highly energetic electrons.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Fluids & Plasmas
C. Z. Xiao, Y. G. Chen, J. F. Myatt, Q. Wang, Y. Chen, Z. J. Liu, C. Y. Zheng, X. T. He
Summary: The theory of absolute stimulated Brillouin side scattering in inhomogeneous flowing plasma is presented and numerically verified. The results show good agreement between theoretical and numerical thresholds under certain conditions, correcting an old threshold. The research also discusses the possibility of finding such instability in current experiments.
Article
Astronomy & Astrophysics
Maria Fedotova, Dmitry Klimachkov, Arakel Petrosyan
Summary: Increased interest in research of non-linear resonant interactions of waves in rotating astrophysical plasma has been seen recently, especially with the discovery of solar magneto-Rossby waves and new data on three-wave interactions of magneto-Rossby waves affecting solar activity. The study highlights magneto-Poincare waves and magneto-Rossby waves in the context of large-scale magnetohydrodynamic flows with rotation, using the beta-plane approximation to simplify the theory of spherical Rossby waves. Analysis of complete dispersion equations on the beta-plane reveals new dispersion relations for magneto-Poincare waves and uncovers new types of three-wave interactions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Fluids & Plasmas
I. H. Hutchinson
Summary: One-dimensional analysis reveals that slow electron holes must be located within a local minimum in the ion velocity distribution to prevent self-acceleration, and quantitative criteria for stable equilibria are obtained. Slow positive potential solitons require a significant contribution from trapped electrons.
Article
Physics, Fluids & Plasmas
F. Cruz, T. Grismayer, L. O. Silva
Summary: This study explores the instability of a uniform, oscillatory plasma equilibrium sustained by a time-dependent current density through analytical and numerical analysis, revealing an infinite number of unstable kinetic modes as well as a kinetic mechanism for the decay of initial modes of infinite wavelength. The growth rate of the fastest growing unstable modes is found to scale with the largest Lorentz factor of the plasma distribution, hinting at a potential relevance in inductive electric field oscillations in pulsar magnetospheres.
Review
Astronomy & Astrophysics
J. S. Pickett
Summary: This review examines the advancements in the understanding of electrostatic solitary waves (ESWs) based on data from the four satellite Cluster mission after 20 years in orbit. ESWs are observed as nonlinear solitary waves or structures in high time resolution waveform data, and are often found in boundary layers, turbulent plasmas, and magnetic reconnection processes, indicating a mix of instabilities and processes contributing to their generation. Studies on the stability and lifetime of these structures through multi-spacecraft propagation have led to a better understanding of the generation mechanisms behind ESWs.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
F. Chu, J. S. Halekas, X. Cao, J. P. McFadden, J. W. Bonnell, K-H Glassmeier
Summary: The researchers found that electrostatic structures above lunar crustal magnetic anomalies interact with the background plasma, resulting in electron heating and scattering. The electron two-stream instability and electron cyclotron drift instability may play important roles in driving electrostatic waves over the lunar magnetic anomalies.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Multidisciplinary Sciences
Sergi Lendinez, Mojtaba T. Kaffash, Olle G. Heinonen, Sebastian Gliga, Ezio Iacocca, M. Benjamin Jungfleisch
Summary: We have discovered the existence of nonlinear magnon-magnon scattering processes and their coherence in ensembles of magnetic nanostructures known as artificial spin ice. Utilizing a combined microwave and microfocused Brillouin light scattering measurement approach, we have found that these systems exhibit effective scattering processes akin to those observed in continuous magnetic thin films. Our results suggest that frequency doubling is enabled by exciting a subset of nanomagnets that act as nanosized antennas, which is similar to scattering in continuous films. Furthermore, directional scattering could be possible in these structures.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
W. Li, Q. Ma, X. -C. Shen, X. -J. Zhang, B. H. Mauk, G. Clark, F. Allegrini, W. S. Kurth, G. B. Hospodarsky, A. Sulaiman, T. A. Nordheim, S. J. Bolton
Summary: During the Juno flyby of Ganymede, significant downward-going electron fluxes and intense whistler-mode waves were observed. Using a quasi-linear model, we determined that quasi-parallel waves dominate the precipitation of higher-energy electrons, while highly oblique waves are important for lower-energy electrons. This study provides new evidence of whistler-mode waves as a potential primary driver of energetic electron precipitation into Ganymede's atmosphere.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Oliver Price, Geraint H. Jones, Karl Battams, Mathew Owens
Summary: The process of forming striated features in cometary dust tails is not yet fully understood. This article uses observations of the tail evolution of C/2011 L4 Pan-STARRS and the reorganisation of striae in the tail of C/2006 P1 McNaught to study the influence of Lorentz forces and solar wind on the alignments of the reorganised striae. The discovery of a bright neutral sodium tail in C/2011 L4 is also reported.
Article
Astronomy & Astrophysics
Qasim Afghan, Geraint H. Jones, Oliver Price, Andrew Coates
Summary: Cometary dust tails exhibit various structures, most of which are believed to be caused by factors such as variable dust production and interactions with the solar wind. However, not all of these structures have been fully understood. This study reports the discovery of a peculiar dust tail feature, where a section of the tail is missing. This suggests a temporary decrease in dust production near perihelion.
Article
Astronomy & Astrophysics
B. Bezdekova, F. Nemec, J. Manninen, O. Santolik, G. B. Hospodarsky, W. S. Kurth
Summary: This study analyzes events with significant intensity enhancements in the 1.5-4 kHz frequency range measured by the ground-based Kannuslehto station in Finland. A total of 465 events are identified in the data collected between December 2012 and October 2019. It is found that these events usually last for several hours and preferentially occur on the dawn side during geomagnetically active periods. Simultaneous measurements from the Van Allen Probes spacecraft are used to determine the L-shells and magnetic local times associated with the intensity increase in space.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
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
D. P. Hartley, I. W. Christopher, C. A. Kletzing, W. S. Kurth, O. Santolik, I. Kolmasova, M. R. Argall, N. Ahmadi
Summary: A new sheath impedance model is developed to explain the effect of variable coupling impedance between Van Allen Probes instruments and ambient plasma on electric field wave measurements. The study quantifies the impact of this sheath correction on measured chorus wave properties and finds that the sheath-corrected electric field wave power is typically 2 to 9 times larger than the uncorrected measurement. The sheath correction also affects the Poynting vector, increasing the Poynting flux by a factor of 2 and changing the propagation direction in 2% of cases.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Review
Astronomy & Astrophysics
P. C. Brandt, E. Provornikova, S. D. Bale, A. Cocoros, R. DeMajistre, K. Dialynas, H. A. Elliott, S. Eriksson, B. Fields, A. Galli, M. E. Hill, M. Horanyi, T. Horbury, S. Hunziker, P. Kollmann, J. Kinnison, G. Fountain, S. M. Krimigis, W. S. Kurth, J. Linsky, C. M. Lisse, K. E. Mandt, W. Magnes, R. L. McNutt, J. Miller, E. Moebius, P. Mostafavi, M. Opher, L. Paxton, F. Plaschke, A. R. Poppe, E. C. Roelof, K. Runyon, S. Redfield, N. Schwadron, V. Sterken, P. Swaczyna, J. Szalay, D. Turner, H. Vannier, R. Wimmer-Schweingruber, P. Wurz, E. J. Zirnstein
Summary: This article provides a detailed overview of the knowledge gaps in our understanding of the interaction between the heliosphere and the largely unexplored Very Local Interstellar Medium (VLISM), as well as predictions of potential scientific discoveries in this field. The article discusses the new measurements needed to make progress in space physics, including in-situ plasma and pick-up ion measurements, direct sampling of VLISM properties, and remote imaging to discern the heliospheric shape and interaction with interstellar hydrogen. A 4-year NASA funded mission study reports the implementation of a pragmatic Interstellar Probe mission with a nominal design life of reaching 375 Astronomical Units (au), with likely operation out to 550 au.
SPACE SCIENCE REVIEWS
(2023)
Review
Astronomy & Astrophysics
C. A. Kletzing, J. Bortnik, G. Hospodarsky, W. S. Kurth, O. Santolik, C. W. Smitth, I. W. Christopher, D. P. Hartley, I. Kolmasova, A. Sen Gupta
Summary: We present a post-mission assessment of the EMFISIS investigation on the NASA Van Allen Probes mission, including important scientific results covering wave modes and DC magnetic fields. The data products, publicly available, are discussed to guide users on the measurements' characteristics and known issues. Guidance on correct use of derived products, particularly the wave-normal analysis and plasma density measurement, is also provided.
SPACE SCIENCE REVIEWS
(2023)
Article
Multidisciplinary Sciences
Ivana Kolmasova, Ondrej Santolik, Masafumi Imai, William S. Kurth, George B. Hospodarsky, John E. P. Connerney, Scott J. Bolton, Radek Lan
Summary: Our understanding of lightning processes at Jupiter was limited by previous measurements. However, recent observations from the Juno mission have provided new insights. The Juno Waves instrument collected data at a resolution of 125 microseconds over a period of 5 years, revealing step-like extensions of lightning channels and indicating similarities between Jovian and intracloud lightning initiation processes on Earth.
NATURE COMMUNICATIONS
(2023)
Article
Astronomy & Astrophysics
F. Nemec, J. Manninen, O. Santolik, G. B. Hospodarsky, W. S. Kurth
Summary: Magnetospheric Line Radiation (MLR) refers to a type of electromagnetic wave phenomenon observed at frequencies of a few kilohertz in the inner magnetosphere. MLR is characterized by a frequency modulation of wave intensity. Although frequently observed by ground-based stations and low-altitude spacecraft, MLR's observations in the equatorial region at larger radial distances are limited due to low frequency resolution. A study using high-resolution multicomponent wave data obtained from Van Allen Probes spacecraft has detected 15 MLR events. These events primarily occur on the dayside and propagate away from the geomagnetic equator.
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
J. D. Menietti, P. H. Yoon, T. F. Averkamp, W. S. Kurth, J. B. Faden, F. Allegrini, P. Kollmann, S. J. Bolton
Summary: The intense Z-mode and O-mode observations in a low to mid-latitude region near the inner edge of the Io torus were reported by the Juno spacecraft in orbit around Jupiter. The density of the plasma in this region was estimated based on the observed Z-mode emission. The results are compatible with electron density measurements from the JADE on board the Juno spacecraft, considering unmeasured cold plasma. Direction-finding measurements indicate that the Z- and O-mode emission have distinct source regions. The importance of Z-mode in accelerating electrons in the inner Jovian magnetosphere makes these new wave mode confirmations at Jupiter of particular interest.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Siyuan Wu, Philippe Zarka, Laurent Lamy, Corentin Louis, Shengyi Ye, Renee Prange, Baptiste Cecconi, William S. S. Kurth
Summary: This study determines and analyzes the high frequency limit (HFL) of Saturnian Kilometric Radiation (SKR) throughout the Cassini Saturn orbital tour. The maximum frequency of northern SKR is shifted to higher values compared to southern SKR, consistent with the magnetic field offset toward the northern hemisphere of Saturn. The study also confirms the modulation of SKR HFL at certain locations and proposes a simulation suggesting the superposition of a clocklike and a rotating source behavior.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Andreas Kvammen, Kristoffer Wickstrom, Samuel Kociscak, Jakub Vaverka, Libor Nouzak, Arnaud Zaslavsky, Kristina Rackovic Babic, Amalie Gjelsvik, David Pisa, Jan Soucek, Ingrid Mann
Summary: This article presents the results of automatically detecting dust impact signals observed by the Solar Orbiter - Radio and Plasma Waves instrument. A novel machine learning-based framework is proposed for dust impact detection and two supervised machine learning approaches are considered. The convolutional neural network achieves the highest performance with a significant improvement compared to the currently used on-board classifier.
ANNALES GEOPHYSICAE
(2023)
Article
Astronomy & Astrophysics
C. K. Louis, P. Louarn, B. Collet, N. Clement, S. Al Saati, J. R. Szalay, V. Hue, L. Lamy, S. Kotsiaros, W. S. Kurth, C. M. Jackman, Y. Wang, M. Blanc, F. Allegrini, J. E. P. Connerney, D. Gershman
Summary: This study focuses on the detection and characterization of radio sources associated with the Galilean moons Io, Europa, and Ganymede at Jupiter. Using data from the Juno spacecraft, this research suggests that the Cyclotron Maser Instability is responsible for the radio signals. The study also highlights the importance of Alfven perturbations and currents in amplifying the radio emissions.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
