Article
Astronomy & Astrophysics
L. F. Burlaga, D. B. Berdichevsky, L. K. Jian, A. Koval, N. F. Ness, J. Park, J. D. Richardson, A. Szabo
Summary: This study presents observations of the magnetic field in the outermost region of the heliosheath by Voyager 2 from 2016 to 2018.6, showing a relatively large average magnetic field strength primarily due to merged interaction regions. The direction of azimuthal angle lambda was close to the Parker spiral magnetic field directions, and the nonextensivity parameter q decreased as solar activity declined. The BT direction was close to the average magnetic field direction, and V2 primarily measured compressible fluctuations.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
E. J. Zirnstein, T. K. Kim, M. A. Dayeh, J. S. Rankin, D. J. McComas, P. Swaczyna
Summary: This study utilizes a dynamic 3D magnetohydrodynamic model to explain the heating process of ions and ENAs in the heliosphere. The study shows that the ENA fluxes at different energy levels are influenced by solar activity and solar wind dynamic pressure, and low-energy ENAs are more affected by solar wind transients.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
L. F. Burlaga, N. Pogorelov, L. K. Jian, J. Park, A. Szabo, N. F. Ness
Summary: Voyager 1 has been traveling through the very local interstellar medium from 2012 to 2023. A sudden increase in magnetic field strength and proton density was observed in 2020, followed by a gradual decline. The magnetic field strength remained strong until the end of the observations.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Matina Gkioulidou, M. Opher, M. Kornbleuth, K. Dialynas, J. Giacalone, J. D. Richardson, G. P. Zank, S. A. Fuselier, D. G. Mitchell, S. M. Krimigis, E. Roussos, I Baliukin
Summary: This study compares the ENA measurements in the heliosheath obtained by IBEX and Cassini/INCA with simulated ENAs, using hybrid simulations. The observed ENA fluxes are consistently higher than the simulated ones, indicating that the termination shock may not accelerate pickup ions to sufficient energies. Further acceleration may occur within the heliosheath through additional physical processes.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Engineering, Aerospace
Skralan Hosteaux, Luciano Rodiguez, Stefaan Poedts
Summary: This paper studies the ICMEs detected by Voyager spacecraft between 1977 and 1980 during their propagation from 1 to 10 AU. The study explores the internal structure of 21 common events detected by both spacecraft and analyzes their plasma and magnetic field properties. The results show that ICMEs expand as they propagate, with decreasing density and magnetic field intensities, consistent with previous studies. The methods described in this paper can be useful for studying other heliospheric missions and emphasize the importance of utilizing valuable data from past missions.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Astronomy & Astrophysics
A. C. Cummings, E. C. Stone, J. D. Richardson, B. C. Heikkila, N. Lal, J. Kota
Summary: Anisotropy results for anomalous cosmic-ray protons were derived for the first time from CRS data during roll maneuvers for the magnetometer instrument onboard Voyager 2 in the inner heliosheath. The radial solar wind speeds derived from the anisotropy vectors show discrepancies with those directly measured by the PLS instrument. Observations suggest that the C-G method underestimates true speeds as Voyager 2 approaches the heliopause.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Anastasia Marchuk, Charles W. Smith, Abigale S. Watson, Matthew R. Argall, Colin J. Joyce, Philip A. Isenberg, Bernard J. Vasquez, Nathan A. Schwadron, Maciej Bzowski, Marzena A. Kubiak, Neil Murphy
Summary: By surveying magnetic field data from the Ulysses spacecraft, magnetic waves excited by newborn pickup He+ were identified, with interstellar neutrals being the likely source for the pickup ions. The waves are seen throughout the Ulysses orbit when growth rates are comparable to or exceed the turbulence rates.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
J. Giacalone, M. Nakanotani, G. P. Zank, J. Kota, M. Opher, J. D. Richardson
Summary: Hybrid simulations were used to estimate the intensity of interstellar pickup protons accelerated to approximately 50 keV along the solar-wind termination shock. Results indicate similar intensities of accelerated pickup protons in the 10-50 keV energy range at different locations, suggesting a relatively uniform distribution along the termination shock and potentially throughout the entire heliosheath. Additionally, significant differences were found in the distribution of energetic neutral atoms in the 0.5-1 keV energy range, depending on the region of the heliosphere from which they originated.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Dae-Young Lee, Sung-Jun Noh
Summary: This study investigates the potential significance of electromagnetic ion cyclotron (EMIC) waves in the inner heliosheath (IHS) and finds a high possibility of frequent triggering of EMIC instability under expected IHS conditions. Numerical calculations indicate significant scattering in pitch angle and energy, suggesting continuous disturbance of ion distributions in the IHS due to prevailing EMIC waves.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
L. F. Burlaga, N. F. Ness, D. B. Berdichevsky, L. K. Jian, W. Kurth, J. Park, J. Rankin, A. Szabo
Summary: Observations of the magnetic field in the very local interstellar medium by Voyager 1 and Voyager 2 reveal the presence of pressure front, shocks, and waves near the heliopause, indicating the existence of complex magnetic field structures and evolution processes within the VLISM.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Lily A. Ercoline, Charles W. Smith, Matthew R. Argall, Colin J. Joyce, Philip A. Isenberg, Bernard J. Vasquez, Nathan A. Schwadron, Justyna M. Sokol, Leonard F. Burlaga
Summary: Interstellar neutral atoms, mainly hydrogen, enter the heliosphere at a slow speed and are eventually ionized by collision with solar wind ions. An analysis of Voyager 1 observations in 1991 revealed low-frequency waves that were likely caused by the interaction of interstellar pickup ions with the local magnetic field. These waves were particularly dense in a region believed to be a Merged Interaction Region (MIR).
ASTROPHYSICAL JOURNAL
(2023)
Article
Engineering, Aerospace
Ezequiel Echer, Adriane Marques de Souza Franco, Fabiola Pinho Magalhaes, Mauricio J. A. Bolzan, Rajkumar Hajra
Summary: The aim of this study is to investigate the turbulence in Neptune's dayside magnetosheath. Analysis of Voyager-2 magnetometer data revealed that most of the magnetosheath magnetic field is aligned in the BT direction. The Fourier spectrum of the magnetic field showed a breakpoint near 0.00165 Hz, with the lower frequency portion having index values smaller than 1.0 and the higher frequency portion having a steeper power law.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Astronomy & Astrophysics
A. T. Michael, M. Opher, G. Toth, V Tenishev, J. F. Drake
Summary: The study found that, even with a kinetic treatment, the two-lobe structure of the heliosphere remains, indicating that magnetic reconnection or instabilities downtail may play a role in its formation.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Joe Giacalone, C. M. S. Cohen, D. J. Mccomas, X. Chen, M. A. Dayeh, W. H. Matthaeus, K. G. Klein, S. D. Bale, E. R. Christian, M. I. Desai, M. E. Hill, L. Y. Khoo, D. Lario, R. A. Leske, R. L. Mcnutt Jr, D. G. Mitchell, J. G. Mitchell, O. Malandraki, N. A. Schwadron
Summary: This article presents analyses of the energetic storm particle event observed by Parker Solar Probe, including the determination of diffusion coefficients and the identification of the source of energetic particles. The study found that the diffusion coefficients were energy-dependent near the shock and nearly energy-independent far upstream of the shock. The source of energetic ions was predominantly the solar wind. The article also proposes a potential explanation for the near-exponential decay of intensity behind the shock.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Multidisciplinary
W. Yao, A. Fazzini, S. N. Chen, K. Burdonov, P. Antici, J. Beard, S. Bolanos, A. Ciardi, R. Diab, E. D. Filippov, S. Kisyov, V Lelasseux, M. Miceli, Q. Moreno, V Nastasa, S. Orlando, S. Pikuz, D. C. Popescu, G. Revet, X. Ribeyre, E. D'Humieres, J. Fuchs
Summary: Laboratory experiments observe proton acceleration by super-critical collisionless shocks, with numerical simulations suggesting shock surfing as the underlying acceleration mechanism. The results not only provide direct evidence of early-stage ion energization by collisionless shocks, but also highlight the role played by this particular mechanism in energizing ambient ions for further stages of acceleration. The research opens up possibilities for exploring the transition to other mechanisms in future laboratory experiments when increasing the magnetic field strength or studying the effects of induced shock front ripples on acceleration processes.
Article
Astronomy & Astrophysics
Y. X. Wang, X. C. Guo, C. Wang, V. Florinski, F. Shen, H. Li, M. Blanc
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2020)
Article
Astronomy & Astrophysics
J. J. Zhang, W. Wang, C. Wang, A. L. Lan, J. Y. Yan, D. Xiang, Q. H. Zhang, J. M. Ruohoniemi, B. S. R. Kunduri, N. Nishitani, X. Shi, H. B. Qiu
EARTH AND SPACE SCIENCE
(2020)
Article
Multidisciplinary Sciences
Qing-He Zhang, Yong-Liang Zhang, Chi Wang, Kjellmar Oksavik, Larry R. Lyons, Michael Lockwood, Hui-Gen Yang, Bin-Bin Tang, Joran Idar Moen, Zan-Yang Xing, Yu-Zhang Ma, Xiang-Yu Wang, Ya-Fei Ning, Li-Dong Xia
Summary: A long-lasting space hurricane was observed in the polar ionosphere and magnetosphere during low solar and geomagnetic activity, showing strong circular horizontal plasma flow and a coincident cyclone-shaped aurora. The hurricane was generated by steady high-latitude lobe magnetic reconnection and current continuity during a period of northward interplanetary magnetic field and very low solar wind density and speed. The observations and simulations revealed the significant impact of this space hurricane on the ionosphere despite otherwise extremely quiet conditions.
NATURE COMMUNICATIONS
(2021)
Article
Geosciences, Multidisciplinary
Fan Gong, Yiqun Yu, Jinbin Cao, Yong Wei, Jiawei Gao, Hui Li, Binzheng Zhang, Aaron Ridley
Summary: This study simulates the solar wind-magnetosphere interactions during a paleomagnetic reversal and finds that the magnetosphere shrinks, with the subsolar magnetopause approaching as close as 3 Re, and multiple magnetic reconnection sites emerge, allowing the solar wind to directly access the magnetosphere and increasing the power transmission efficiency to 18%.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
V. F. Andrioli, J. Xu, P. P. Batista, L. C. A. Resende, L. A. Da Silva, J. P. Marchezi, H. Li, C. Wang, Z. Liu, A. Guharay
Summary: This study analyzed the tidal components of mesospheric winds at Cachoeira Paulista, Brazil, based on 21 years of meteor radar data. It was found that the meridional diurnal and semidiurnal tides have higher amplitudes during solar minimum, while the zonal tides have higher amplitudes during solar maximum. The study also discussed the physical mechanism behind the influence of high-speed stream events and solar activity on tidal amplitudes.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Wence Jiang, Daniel Verscharen, Hui Li, Chi Wang, Kristopher G. Klein
Summary: This study reveals the local generation mechanism of whistler waves in magnetic holes and confirms the significance of wave-particle interactions in the evolution of magnetic holes and astrophysical plasmas.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Peishan He, Xiaojun Xu, Hsinchen Yu, Xing Wang, Ming Wang, Qing Chang, Zilu Zhou, Lei Luo, Hui Li
Summary: This study investigated the effects of background solar wind conditions on the shape and location of Mercury's bow shock. The results demonstrated that the bow shock moves antiplanetward as Mercury moves from perihelion to aphelion, but the difference is not as significant as that of the magnetopause. The orientation of the interplanetary magnetic field has a weak influence on the bow shock.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
S. Roy, R. Bandyopadhyay, Y. Yang, T. N. Parashar, W. H. Matthaeus, S. Adhikari, V. Roytershteyn, A. Chasapis, Hui Li, D. J. Gershman, B. L. Giles, J. L. Burch
Summary: Despite decades of study, a complete understanding of energy transfer in turbulent plasmas remains elusive. This study demonstrates the connection between fluid-scale energy transfer and kinetic-scale dissipation using simulations and observations, and proposes a phenomenology based on proton cyclotron time and plasma beta.
ASTROPHYSICAL JOURNAL
(2022)
Article
Mechanics
Lei Luo, Xiaojun Xu, Yu Zhang, Zilu Zhou, Qing Chang, Qi Xu, Xing Wang, Peishan He, Siqi Yi, Hui Li
Summary: The two-fluid generalized Ohm's law (GOL) is proposed based on the assumption of a plasma consisting of only protons and electrons. The three-fluid GOL is obtained theoretically for the three-fluid plasma consisting of heavy ions, light ions, and electrons, which is found in planetary ionospheres and magnetospheres. The study derives three inertial lengths and explores the modification of ion inertial lengths, reconnection rate, and Hall magnetic and electric fields due to the two-step decoupling process of ions. The findings provide a framework to expand the reconnection theory to include more ion species.
Article
Astronomy & Astrophysics
Wence Jiang, Hui Li, Xiaodong Liu, Daniel Verscharen, Chi Wang
Summary: The Martian magnetosheath, with its unique magnetic-field spectra and plateau-like spectral feature, provides a natural laboratory to study plasma turbulence in the presence of pickup ions and instabilities. The occurrence rate of plateau-like spectra is found to be approximately 56.6% and can increase to around 70.0% at moderate pickup angles. The presence of plateau-like spectra is positively correlated with the local ion density and negatively correlated with the local beta(i) and solar Extreme Ultra Violet irradiance. These results suggest that the pickup ion driven micro-instabilities in the Martian magnetosheath do not have enough time to fully develop into a cascade.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Xiaojun Xu, Xing Wang, Zilu Zhou, Qing Chang, Lei Luo, Peishan He, Siqi Yi, Hui Li
Summary: This study presents observations of a potentially ceased reconnection exhaust in the Martian magnetosheath. The exhaust contains a reconnection jet with abundant heavy ions that flows outward to space. Magnetic field lines within the exhaust are found to be draped, indicating detachment from the ionosphere and escape of heavy ions from Mars. The findings demonstrate that magnetic reconnection can contribute directly to ion loss from Mars.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Juliano Moro, Jiyao Xu, Clezio Marcos Denardini, Laysa Cristina Araujo Resende, Regia Pereira Silva, Sony Su Chen, Giorgio Arlan da Silva Picanco, Liu Zhengkuan, Hui Li, Chunxiao Yan, Chi Wang, Nelson Jorge Schuch
ANNALES GEOPHYSICAE
(2020)
Article
Astronomy & Astrophysics
Hui Li, Nianwang Li, Chi Wang, Shuo Yao
ASTROPHYSICAL JOURNAL LETTERS
(2020)
Article
Astronomy & Astrophysics
Chen Zeng, Suping Duan, Chi Wang, Lei Dai, Stephen Fuselier, James Burch, Roy Torbert, Barbara Giles, Christopher Russell
ANNALES GEOPHYSICAE
(2020)
