Article
Physics, Multidisciplinary
Qiang Liu, Yan Zhao, Guoqing Zhao
Summary: This study surveyed 63 small-scale interplanetary magnetic flux ropes (SIMFRs) found within a 6-day window around the heliospheric current sheet (HCS) and found that the majority of SIMFRs were quasi-parallel to the associated HCS, with statistically shorter durations compared to cases quasi-perpendicular to the HCS. This suggests that most of these SIMFRs may be generated in the nearby HCSs.
FRONTIERS IN PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
K. Jiang, S. Y. Huang, Z. G. Yuan, X. H. Deng, Y. Y. Wei, Q. Y. Xiong, S. B. Xu, J. Zhang, Z. H. Zhang, R. T. Lin, L. Yu
Summary: A statistical analysis was performed on current density, energy conversion, and electron acceleration in primary and secondary flux ropes, showing differences and patterns that can enhance understanding of their roles in magnetotail dynamics.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
M. Hubbert, Y. Qi, C. T. Russell, J. L. Burch, B. L. Giles, T. E. Moore
Summary: This report examines tail current sheets supported only by electron currents in Earth's magnetotail. Three of these current sheets are interpreted in terms of the time-evolution of reconnection onset, showing evidence of parallel electron heating, perpendicular ion heating, and current sheet expansion. The data suggests that electron-only reconnection can act as a precursor to electron-ion reconnection, but also that it is more than merely a precursor to ion reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Physics, Multidisciplinary
Hengqiang Feng, Yan Zhao, Jiemin Wang, Qiang Liu, Guoqing Zhao
Summary: This paper examines the evolution of closed magnetic flux ropes in interplanetary space using data collected by the Wind spacecraft in 1997. The study finds that interchange reconnection and disconnection are important mechanisms that change the magnetic topology of flux ropes during their propagation.
FRONTIERS IN PHYSICS
(2021)
Article
Astronomy & Astrophysics
P. F. Wyper, D. I. Pontin
Summary: Observations of solar flare ribbons show significant fine structure, such as breaking wavelike perturbations and spirals. It is suggested that this structure is related to tearing instability in the flare current sheet, with a direct link between flare ribbon fine structure and tearing modes. The size, location, and twist of small-scale flux ropes can influence the formation of wavelike and spiral features within the flare ribbon.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Fluids & Plasmas
T. K. M. Nakamura, W. -l. Teh, S. Zenitani, T. Umeda, M. Oka, H. Hasegawa, A. M. Veronig, R. Nakamura
Summary: Magnetic reconnection is a fundamental process that converts magnetic energy to plasma kinetic energy in collisionless plasmas. This study focuses on the coalescence of multiple magnetic islands and examines the spatial dimensions of the internal structures. It is found that the dimensions depend on the initial thickness of the current sheet and the number of coalescing islands. The study also discovers that the horizontal dimension controls the evolution time scale, while the vertical dimension affects the reconnection maturity and particle heating.
PHYSICS OF PLASMAS
(2023)
Article
Astronomy & Astrophysics
S. Y. Huang, Q. Y. Xiong, L. F. Song, J. Nan, Z. G. Yuan, K. Jiang, X. H. Deng, L. Yu
Summary: Observations suggest the presence of electron-only magnetic reconnection without ion coupling in a current sheet, challenging the standard model of magnetic reconnection. The inner electron diffusion region observed is much longer than predicted by theory, indicating a need for further understanding of electron-scale reconnection.
ASTROPHYSICAL JOURNAL
(2021)
Article
Geosciences, Multidisciplinary
H. -W. Wang, B. -B. Tang, W. Y. Li, Y. -C. Zhang, D. B. Graham, Y. V. Khotyaintsev, C. -H. Gao, X. -C. Guo, C. Wang
Summary: In this study, detailed electron dynamics in strong guide-field reconnection are investigated. Observations show the presence of a large parallel electric field, with electrons being accelerated or decelerated depending on their direction of entry. We propose that electron beta is an important parameter in guide-field reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
H. Hasegawa, R. E. Denton, K. Dokgo, K. -J Hwang, T. K. M. Nakamura, J. L. Burch
Summary: This study analyzes three flux transfer events (FTEs) and subsequent crossing of a reconnecting magnetopause current sheet (MPCS) observed by the Magnetospheric Multiscale spacecraft. The aim is to understand the generation mechanism of ion-scale magnetic flux ropes (ISFRs) and their relationship with electromagnetic energy conversion and kinetic processes. The results show that ISFRs can be generated through secondary reconnection in an electron-scale current sheet (ECS), and the FTEs also formed through the same secondary reconnection process. Observations also suggest complex magnetic topology and localized conversion of electromagnetic to electron energy in the ISFR.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Multidisciplinary Sciences
Young Dae Yoon, Deirdre Wendel, Gunsu Yun
Summary: Although a continuous spectrum of current sheet equilibria exists, how a particular equilibrium is selected by a system remains unknown. This study reveals the exact process of equilibrium selection by analyzing the relaxation process of an unequilibrated current sheet with a finite guide field. The results demonstrate that the current sheet relaxes in a way that locally amplifies the guide field, leading to a mixed equilibrium. Comparisons with spacecraft observations and solar wind current sheet statistics show that such mixed equilibria are common and act as underlying local structures in various physical environments.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Y. C. Xiao, S. T. Yao, R. L. Guo, Q. Q. Shi, Q. G. Zong, H. Zhang, S. C. Bai, M. Hamrin, T. Pitkanen, A. M. Tian, A. W. Degeling, J. Liu
Summary: This study uses the Magnetospheric Multiscale satellite to statistically analyze kinetic-scale flux ropes (KSFRs) in the Earth's dayside magnetosheath. The study finds that the majority of KSFRs are generated near the bow shock and propagate downstream. The occurrence rate of KSFRs is influenced by solar wind parameters, similar to conditions favoring bow shock reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Review
Astronomy & Astrophysics
O. Khabarova, O. Malandraki, H. Malova, R. Kislov, A. Greco, R. Bruno, O. Pezzi, S. Servidio, Gang Li, W. Matthaeus, J. Le Roux, N. E. Engelbrecht, F. Pecora, L. Zelenyi, V Obridko, V Kuznetsov
Summary: Recent studies in the heliosphere have shifted the focus from a 2D perspective to a more comprehensive understanding of 3D processes, revealing previously unimaginable dynamics through simulations and observations. Current research is centered on exploring plasma structures and their observations in the heliosphere.
SPACE SCIENCE REVIEWS
(2021)
Article
Astronomy & Astrophysics
Z. H. Zhong, G. Y. Lei, M. Zhou, M. Zhang, R. X. Tang, D. B. Graham, Y. Pang, X. H. Deng, Yu. V. Khotyaintsev
Summary: This paper presents the magnetospheric multiscale (MMS) observations of three flux ropes (FRs) sequentially in a reconnection exhaust at Earth's magnetopause. Three active X-lines, responsible for the formation of these FRs, were detected by MMS, providing strong evidence for multiple X-line reconnection. The core field inside the FRs significantly influences the Hall current in the adjacent X-lines, deflecting the electron outflow jet and forming electron-scale Hall magnetic field. Additionally, an active secondary reconnection was observed, splitting one FR into two smaller FRs and generating sharp density gradients and intense fluctuations of electric field and current.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
K. K. Khurana, H. K. Leinweber, G. B. Hospodarsky, C. P. Paranicas
Summary: The structures and thickness of the Jovian magnetospheric current sheet are analyzed using magnetic field observations from various spacecraft. A new technique is used to determine the motion of the spacecraft relative to the current sheet and a global map of the current sheet thickness is created. The current sheet is found to be non-uniform and varies with radial distance and local time. The thin dawnside current sheet is likely related to the solar wind's impact on the magnetosphere, while the dusk sector shows evidence of a mostly closed magnetosphere. The asymmetries in current sheet thickness are believed to be a result of the reconnection of the interplanetary and Jupiter's magnetic fields.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
David Kramolis, Miroslav Barta, Michal Varady, Radoslav Bucik
Summary: This study investigates ion acceleration in spontaneously fragmenting flare current sheets (SFCS) and analyzes the impact of plasmoid cascades on the acceleration of specific ions. The study identifies regions of efficient ion acceleration, analyzes accelerator efficiency, and determines the spectra of the accelerated ions. The results show agreement with observed data but exhibit slight variations in abundance-enhancement factors compared to observational data.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
F. Kiefer, V. Van Grootel, A. Lecavelier des Etangs, Gy. M. Szabo, A. Brandeker, C. Broeg, A. Collier Cameron, A. Deline, G. Olofsson, T. G. Wilson, S. G. Sousa, D. Gandolfi, G. Hebrard, Y. Alibert, R. Alonso, G. Anglada, T. Barczy, D. Barrado, S. C. C. Barros, W. Baumjohann, M. Beck, T. Beck, W. Benz, N. Billot, X. Bonfils, J. Cabrera, S. Charnoz, Sz. Csizmadia, M. B. Davies, M. Deleuil, L. Delrez, O. D. S. Demangeon, B. -o. Demory, D. Ehrenreich, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, M. Gillon, M. Guedel, K. Heng, S. Hoyer, K. G. Isaak, L. L. Kiss, J. Laskar, M. Lendl, C. Lovis, D. Magrin, P. F. L. Maxted, M. Munari, V. Nascimbeni, R. Ottensamer, I. Pagano, E. Palle, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, F. Ratti, H. Rauer, C. Reimers, I. Ribas, N. C. Santos, G. Scandariato, D. Segransan, A. E. Simon, A. M. S. Smith, M. Steller, N. Thomas, S. Udry, I. Walter, N. A. Walton
Summary: HD172555 is a young A7V star with a 10 au wide debris disk, potentially formed by collisions between large planetesimals. Spectroscopy has detected evaporating bodies, or exocomets, in this system, making it another possible example of a system experiencing heavy bombardment of planetesimals. By using transit photometry, the researchers aim to determine the dust content of these small bodies. Through a 2-day photometric monitoring with the CHEOPS space telescope, they found evidence of a transient absorption, corresponding to an exocomet passing near the star with similar properties to those previously detected in this system.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
S. Sulis, M. Lendl, H. M. Cegla, L. F. Rodriguez Diaz, L. Bigot, V. Van Grootel, A. Bekkelien, A. Collier Cameron, P. F. L. Maxted, A. E. Simon, C. Lovis, G. Scandariato, G. Bruno, D. Nardiello, A. Bonfanti, M. Fridlund, C. M. Persson, S. Salmon, S. G. Sousa, T. G. Wilson, A. Krenn, S. Hoyer, A. Santerne, D. Ehrenreich, Y. Alibert, R. Alonso, G. Anglada, T. Barczy, D. Barrado y Navascues, S. C. C. Barros, W. Baumjohann, M. Beck, T. Beck, W. Benz, N. Billot, X. Bonfils, L. Borsato, A. Brandeker, C. Broeg, J. Cabrera, S. Charnoz, C. Corral van Damme, Sz Csizmadia, M. B. Davies, M. Deleuil, A. Deline, L. Delrez, O. D. S. Demangeon, B-O Demory, A. Erikson, A. Fortier, L. Fossati, D. Gandolfi, M. Gillon, M. Guedel, K. Heng, K. G. Isaak, L. L. Kiss, J. Laskar, A. Lecavelier des Etangs, D. Magrin, M. Munari, V Nascimbeni, G. Olofsson, R. Ottensamer, I Pagano, E. Palle, G. Peter, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I Ribas, M. Rieder, N. C. Santos, D. Segransan, A. M. S. Smith, M. Steinberger, M. Steller, Gy M. Szabo, N. Thomas, S. Udry, N. A. Walton, D. Wolter
Summary: This study aims to detect the signatures of stellar granulation, linking spectroscopic and photometric signatures for main-sequence stars and testing predictions from 3D hydrodynamic models. By observing two bright stars with high precision and comparing the results with other observations and models, the characteristics and properties of stellar granulation were determined. This research is important for future missions and high-precision radial velocity surveys.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Geosciences, Multidisciplinary
Andreas Johlander, Yuri V. V. Khotyaintsev, Andrew P. P. Dimmock, Daniel B. B. Graham, Ahmad Lalti
Summary: Electron heating at collisionless shocks is a result of adiabatic heating from large-scale electric and magnetic fields and non-adiabatic scattering from high-frequency fluctuations. This study uses data from the Magnetospheric Multiscale (MMS) spacecraft to investigate electron heating scales at Earth's quasi-perpendicular bow shock. By measuring the electron temperature gradient, the electron temperature profile inside the shock ramp is reconstructed, revealing that the temperature increase occurs on ion or sub-ion scales. Additionally, Liouville mapping is utilized to estimate the deHoffmann-Teller potential and electric field, showing that electron heating is highly non-adiabatic in high-Mach number shocks.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
K. W. F. Lam, J. Cabrera, M. J. Hooton, Y. Alibert, A. Bonfanti, M. Beck, A. Deline, H-G Floren, A. E. Simon, L. Fossati, C. M. Persson, M. Fridlund, S. Salmon, S. Hoyer, H. P. Osborn, T. G. Wilson, I. Y. Georgieva, Gr Nowak, R. Luque, J. A. Egger, V Adibekyan, R. Alonso, G. A. Escude, T. Barczy, D. Barrado, S. C. C. Barros, W. Baumjohann, T. Beck, A. Bekkelien, W. Benz, N. Billot, X. Bonfils, A. Brandeker, C. Broeg, S. Charnoz, A. C. Cameron, Sz Csizmadia, M. B. Davies, M. Deleuil, L. Delrez, O. D. S. Demangeon, B-O Demory, D. Ehrenreich, A. Erikson, A. Fortier, D. Futyan, D. Gandolfi, M. Gillon, M. Guedel, P. Guterman, J. Laskar, D. W. Latham, A. Lecavelier des Etangs, M. Lendl, C. Lovis, K. Heng, K. G. Isaak, L. Kiss, D. Magrin, P. F. L. Maxted, V Nascimbeni, G. Olofsson, R. Ottensamer, I Pagano, E. Palle, G. Peter, G. Piotto, D. Pollacco, D. Queloz, I Ribas, R. Ragazzoni, N. Rando, H. Rauer, N. C. Santos, G. Scandariato, S. Seager, D. Segransan, L. M. Serrano, A. M. S. Smith, S. G. Sousa, M. Steller, Gy M. Szabo, N. Thomas, S. Udry, V. Van Grootel, N. A. Walton, J. N. Winn
Summary: We have discovered a third planet in the TOI-1260 system, which is already known to have two transiting sub-Neptune planets. The discovery is supported by ground-based follow-up observations and precise photometric monitoring. The improved radius measurements provide valuable insights into the composition and interior structure of the planets.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Geosciences, Multidisciplinary
H. -W. Wang, B. -B. Tang, W. Y. Li, Y. -C. Zhang, D. B. Graham, Y. V. Khotyaintsev, C. -H. Gao, X. -C. Guo, C. Wang
Summary: In this study, detailed electron dynamics in strong guide-field reconnection are investigated. Observations show the presence of a large parallel electric field, with electrons being accelerated or decelerated depending on their direction of entry. We propose that electron beta is an important parameter in guide-field reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
C. -h. Gao, B. -b. Tang, X. -c. Guo, W. Y. Li, Y. V. Khotyaintsev, D. B. Graham, D. L. Turner, Z. W. Yang, C. Wang
Summary: Agyrotropic electron distributions, previously believed to indicate electron diffusion regions of magnetic reconnection, have been found to also occur at non-reconnecting magnetopause boundaries due to the electron finite gyroradius effect. This study presents observations in the Earth's magnetotail that show the presence of agyrotropic electron distributions in the foreshock region. These distributions are generated by the electron finite gyroradius effect after magnetic curvature scattering at a thin electron-scale boundary, without any signatures of magnetic reconnection. Test-particle simulations confirm the generation of agyrotropic electron distributions. These findings suggest that such distributions can occur more widely in the space plasma environment.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Faith Hawthorn, Daniel Bayliss, Thomas G. Wilson, Andrea Bonfanti, Vardan Adibekyan, Yann Alibert, Sergio G. Sousa, Karen A. Collins, Edward M. Bryant, Ares Osborn, David J. Armstrong, Lyu Abe, Jack S. Acton, Brett C. Addison, Karim Agabi, Roi Alonso, Douglas R. Alves, Guillem Anglada-Escude, Tamas Barczy, Thomas Barclay, David Barrado, Susana C. C. Barros, Wolfgang Baumjohann, Philippe Bendjoya, Willy Benz, Allyson Bieryla, Xavier Bonfils, Francois Bouchy, Alexis Brandeker, Christopher Broeg, David J. A. Brown, Matthew R. Burleigh, Marco Buttu, Juan Cabrera, Douglas A. Caldwell, Sarah L. Casewell, David Charbonneau, Sebastian Charnoz, Ryan Cloutier, Andrew Collier Cameron, Kevin Collins, Dennis M. Conti, Nicolas Crouzet, Szilard Czismadia, Melvyn B. Davies, Magali Deleuil, Elisa Delgado-Mena, Laetitia Delrez, Olivier D. S. Demangeon, Brice-Olivier Demory, Georgina Dransfield, Xavier Dumusque, Jo Ann Egger, David Ehrenreich, Philipp Eigmueller, Anders Erickson, Zahra Essack, Andrea Fortier, Luca Fossati, Malcolm Fridlund, Maximilian N. Gunther, Manuel Guedel, Davide Gandolfi, Harvey Gillard, Michael Gillon, Crystal Gnilka, Michael R. Goad, Robert F. Goeke, Tristan Guillot, Andreas Hadjigeorghiou, Coel Hellier, Beth A. Henderson, Kevin Heng, Matthew J. Hooton, Keith Horne, Steve B. Howell, Sergio Hoyer, Jonathan M. Irwin, James S. Jenkins, Jon M. Jenkins, Eric L. N. Jensen, Stephen R. Kane, Alicia Kendall, John F. Kielkopf, Laszlo L. Kiss, Gaia Lacedelli, Jacques Laskar, David W. Latham, Alain Lecavalier des Etangs, Adrien Leleu, Monika Lendl, Jorge Lillo-Box, Christophe Lovis, Djamel Mekarnia, Bob Massey, Tamzin Masters, Pierre F. L. Maxted, Valerio Nascimbeni, Louise D. Nielsen, Sean M. O'Brien, Goran Olofsson, Hugh P. Osborn, Isabella Pagano, Enric Palle, Carina M. Persson, Giampaolo Piotto, Peter Plavchan, Don Pollacco, Didier Queloz, Roberto Ragazzoni, Heike Rauer, Ignasi Ribas, George Ricker, Damien Segransan, Sebastien Salmon, Alexandre Santerne, Nuno C. Santos, Gaetano Scandariato, Francois-Xavier Schmider, Richard P. Schwarz, Sara Seager, Avi Shporer, Attila E. Simon, Alexis M. S. Smith, Gregor Srdoc, Manfred Steller, Olga Suarez, Gyula M. Szabo, Johanna Teske, Nicolas Thomas, Rosanna H. Tilbrook, Amaury H. M. J. Triaud, Stephane Udry, Valerie Van Grootel, Nicholas Walton, Sharon X. Wang, Peter J. Wheatley, Joshua N. Winn, Robert A. Wittenmyer, Hui Zhang
Summary: We have discovered two exoplanets transiting TOI-836 through data analysis from TESS Sector 11 and Sector 38. TOI-836 is a bright K-dwarf with high proper motion and low metallicity. The inner planet, TOI-836 b, is a super-Earth located in the radius valley, while the outer planet, TOI-836 c, is a mini-Neptune. Radial velocity measurements reveal the masses of both planets, and photometric observations show Transit Timing Variations (TTVs) for TOI-836 c.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Fluids & Plasmas
T. K. M. Nakamura, W. -l. Teh, S. Zenitani, T. Umeda, M. Oka, H. Hasegawa, A. M. Veronig, R. Nakamura
Summary: Magnetic reconnection is a fundamental process that converts magnetic energy to plasma kinetic energy in collisionless plasmas. This study focuses on the coalescence of multiple magnetic islands and examines the spatial dimensions of the internal structures. It is found that the dimensions depend on the initial thickness of the current sheet and the number of coalescing islands. The study also discovers that the horizontal dimension controls the evolution time scale, while the vertical dimension affects the reconnection maturity and particle heating.
PHYSICS OF PLASMAS
(2023)
Article
Astronomy & Astrophysics
G. Cozzani, Yu. V. Khotyaintsev, D. B. Graham, M. Andre
Summary: Electron temperature anisotropy-driven instabilities like the electron firehose instability (EFI) are important in collisionless plasmas, especially in space. This study uses in situ measurements to observe EFI fluctuations in the magnetic reconnection exhaust in Earth's magnetotail. The observed fluctuations agree with theoretical predictions and provide the first direct in situ observations of EFI-generated fluctuations.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
D. Teubenbacher, O. W. Roberts, R. Nakamura, Y. Narita, Z. Voeroes, K. Torkar, P. -A. Lindqvist, R. E. Ergun
Summary: In this study, the Magnetospheric Multiscale (MMS) mission data is utilized to estimate electron density and analyze compressive turbulence in the Earth's magnetosheath. The MMS Solar Wind Turbulence Campaign in February 2019 provided multiple spacecraft measurements at varying distances for a detailed investigation. The derived electron density data has higher temporal resolution compared to plasma instruments, allowing examination of fluctuations at sub-ion scales. The findings suggest different drivers in the strongly compressive magnetosheath and the weakly compressive solar wind, with compressive structures potentially playing significant roles.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Iannis Dandouras, Matt G. G. T. Taylor, Johan De Keyser, Yoshifumi Futaana, Ruth A. Bamford, Graziella Branduardi-Raymont, Jean-Yves Chaufray, Dragos Constantinescu, Elisabetta De Angelis, Pierre Devoto, Jonathan Eastwood, Marius Echim, Philippe Garnier, Benjamin Grison, David Hercik, Helmut Lammer, Andre Laurens, Francois Leblanc, Anna Milillo, Rumi Nakamura, Lubomir Prech, Elias Roussos, Stepan Stverak, Julien Forest, Arnaud Trouche, Sebastien L. G. Hess, Jean-Charles Mateo-Velez, James Carpenter, Josef Winter
Summary: The Lunar Orbital Platform - Gateway (LOP-Gateway), assembled and operated by NASA and international partner organizations, offers new opportunities for scientific research in the vicinity of the Moon. It provides a unique location to study the deep space plasma environment and its interaction with the lunar surface and exosphere. This paper explores the potential of externally mounted payloads on the Gateway for space plasma physics research and the impact of the space environment on an inhabited platform.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Astronomy & Astrophysics
Z. C. Tian, M. Zhou, H. Y. Man, Z. H. Zhong, X. H. Deng, D. J. Gershman, Y. V. Khotyaintsev, C. T. Russell
Summary: This paper presents the simultaneous observation of the inner and outer electron diffusion region (EDR) in magnetic reconnection with a large guide field at the dayside magnetopause by the magnetospheric multiscale (MMS) spacecraft. The inner EDR is characterized by positive J·E', while the outer EDR is manifested by negative J·E' and opposite out-of-plane electric field. The observation of bidirectional accelerated electron jets on the opposite side of the X-line is significant, and the fortuitous formation of MMS provides estimates for the length of the inner EDR and the reconnection rate.
ASTROPHYSICAL JOURNAL
(2023)
Article
Geosciences, Multidisciplinary
Tongkuai Li, Wenya Li, Binbin Tang, Yuri. V. Khotyaintsev, Daniel Bruce Graham, Akhtar Ardakani, J. L. Burch, D. J. Gershman, B. Lavraud, C. T. Russell, Quanming Lu, Xiaocheng Guo, Chi Wang
Summary: This study presents Magnetospheric Multiscale (MMS) observations of a K-H wave event accompanied by ongoing magnetic reconnection under southward IMF conditions. The nonlinear K-H waves exhibit quasi-periodic fluctuations, presence of low-density and high-speed ions, and variations in the boundary normal vectors. Through the identification of Alfvenic ion jets and the escape of energetic magnetospheric electrons, clear evidence of on-going magnetic reconnection is revealed. Notably, out of the 36 magnetopause current-sheet crossings in this event, 19 exhibit unambiguous signatures of reconnection at both the leading and trailing edges, indicating the compression effect resulting from the large-scale evolution of the K-H waves.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
S. W. Alqeeq, O. Le Contel, P. Canu, A. Retino, T. Chust, L. Mirioni, A. Chuvatin, R. Nakamura, N. Ahmadi, F. D. Wilder, D. J. Gershman, Yu. V. Khotyaintsev, P. -A. Lindqvist, R. E. Ergun, J. L. Burch, R. B. Torbert, S. A. Fuselier, C. T. Russell, H. Y. Wei, R. J. Strangeway, K. R. Bromund, D. Fischer, B. L. Giles, Y. Saito
Summary: In this study, a statistical analysis of equatorial dipolarization fronts (DFs) detected by the Magnetospheric Multiscale mission during the 2017 magnetotail season was conducted. Two distinct classes of DFs were identified: class I, which corresponds to the standard DF properties and energy dissipation, and class II, a new class that features a bump in the magnetic field, a minimum in ion and electron pressures, and a reversal of the energy conversion process. The study also reveals that the energy conversion processes of these two classes of DFs differ in the spacecraft frame and fluid frame, mainly due to variations in the electric fields.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Niklas Grimmich, Ferdinand Plaschke, Martin O. Archer, Daniel Heyner, Johannes Z. D. Mieth, Rumi Nakamura, David G. Sibeck
Summary: The magnetopause (MP) is primarily determined by the pressure balance between the solar wind and the magnetosphere. The boundary can move due to different solar wind conditions and transient foreshock phenomena, resulting in unusually large or small distances from the Earth. In this study, we investigate the occurrence of extreme MP distortions under specific solar wind conditions and identify several parameters, such as IMF magnitude, cone angle, velocity, Alfven Mach number, and temperature, that are linked to these extreme events. The findings have implications for future magnetopause models and the reconstruction of MP locations using soft X-ray images for missions like SMILE.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)