Article
Geosciences, Multidisciplinary
Xiao-Jia Zhang, Xing Meng, Anton V. Artemyev, Ying Zou, Didier Mourenas
Summary: Energetic electron precipitation from the equatorial magnetosphere into the atmosphere is crucial for magnetosphere-ionosphere coupling. This study aims to address the mapping uncertainties between ionospheric measurements and measurements of wave and energetic electron properties by projecting low-altitude measurements onto total electron content (TEC) maps. The distinct features of different types of precipitation in TEC horizontal gradients are discussed.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
H. Han, S. J. Park, C. Sung, J. Kang, Y. H. Lee, J. Chung, T. S. Hahm, B. Kim, J-K Park, J. G. Bak, M. S. Cha, G. J. Choi, M. J. Choi, J. Gwak, S. H. Hahn, J. Jang, K. C. Lee, J. H. Kim, S. K. Kim, W. C. Kim, J. Ko, W. H. Ko, C. Y. Lee, J. H. Lee, J. K. Lee, J. P. Lee, K. D. Lee, Y. S. Park, J. Seo, S. M. Yang, S. W. Yoon, Y-S Na
Summary: Nuclear fusion is a promising alternative energy source, but there are still many scientific challenges to harnessing fusion energy on a large scale. Researchers have achieved a plasma fusion regime at the Korea Superconducting Tokamak Advanced Research facility that meets most of the requirements for sustainable fusion. By stabilizing core plasma turbulence with abundant fast ions, they were able to generate plasma at a temperature of 100 million kelvin, lasting up to 20 seconds without instabilities or impurity accumulation. This regime, characterized by low plasma density and moderate input power, shows promise for reliable and disruption-free sustained operation, making it a potential path towards commercial fusion reactors.
Article
Geosciences, Multidisciplinary
Zhekai Luo, Lun Xie, Suiyan Fu, Zuyin Pu, Ying Xiong, Xuzhi Zhou, Qiugang Zong, Li Li, C. T. Russell, R. E. Ergun, J. L. Burch, J. B. Blake, R. B. Torbert, P. -A. Lindqvist
Summary: This paper analyzes the features of drift resonance in microinjection phenomena and proposes a new theory that includes bouncing electrons. The observed phase differences in microinjection events are consistent with the predicted phase differences based on the new theory, suggesting that drift resonance may act as the forming mechanism for microinjections.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Multidisciplinary
Ren GanMing, Cao JinBin, Yang Jian, Malcolm Wray Dunlop
Summary: It was found that plasma parameters and energy transport in the plasma sheet react to changes in the direction of the north/south interplanetary magnetic field (IMF) with varying response times. Enthalpy flux plays a dominant role in plasma sheet energy transport, and the response time of energy transport is different after northward and southward IMF turnings.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2021)
Article
Environmental Sciences
Bingkun Yu, Xianghui Xue, Christopher J. Scott, Jianfei Wu, Xinan Yue, Wuhu Feng, Yutian Chi, Daniel R. Marsh, Hanli Liu, Xiankang Dou, John M. C. Plane
Summary: This study investigates ionospheric irregularities using scintillation data from COSMIC satellites and simulations from the Whole Atmosphere Community Climate Model, combined with the chemistry of metals and ground-based observations. The results show that the lower thermospheric meridional circulation influences the transport of metallic ions within sporadic E layers, with implications for large-scale interhemispheric transport in the thermosphere-ionosphere system.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Physics, Multidisciplinary
A. S. El-Said, W. M. Moslem, R. E. Tolba, H. Bahlouli
Summary: Highly energetic heavy ions are effective in surface nanostructuring of various materials. The irradiation of strontium titanate with GeV xenon ions can create surface nanohillocks, with each hillock produced by a single ion impact. We present a new approach to explain the creation mechanism of nano-sized hillocks, which is based on the ability of ion-induced strong electronic excitations to form localized plasma. The existence of nonlinear ion-acoustic mode in the plasma indicates the features of the nanohillocks. The solution of plasma hydrodynamic equations shows a bell-shaped relation between the normalized electron number density and distance along the crystal. The similarity to the hillock profile suggests the importance of electron density in producing the observed surface structures. Furthermore, the utilized model explains the creation mechanism of hillocks-like structures in cases of normal incidence and grazing incidence of highly energetic heavy ions.
Article
Astronomy & Astrophysics
Lei Cheng, Ming Zhang, David Lario, Laura A. Balmaceda, Ryun Young Kwon, Christina Cohen
Summary: This paper presents a stochastic three-dimensional focused transport simulation of solar energetic particles (SEPs) produced by a data-driven coronal mass ejection (CME) shock. The model is applied to a SEP event observed by STEREO-A and Parker Solar Probe. The simulation results are well correlated with observations, suggesting that the SEP event could be explained by the acceleration of particles by a weak CME shock.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Yangyang Shen, Anton V. Artemyev, Andrei Runov, Vassilis Angelopoulos, Jiang Liu, Xiao-Jia Zhang, James M. Weygand, Jiashu Wu, Ethan Tsai, Colin Wilkins
Summary: This study presents the first statistical analysis of low-altitude observations of magnetospheric particles, specifically focusing on energetic electron flux dropouts in the low-altitude projection of the plasma sheet. The results provide insights into the occurrence distribution and characteristics of these events, as well as the magnetospheric drivers and magnetic field conditions that lead to such dropouts as viewed by ELFIN.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Geosciences, Multidisciplinary
Q. Ma, W. Li, X-J Zhang, X-C Shen, A. Daly, J. Bortnik, B. H. Mauk, P. Kollmann, C. Paranicas, H. N. Becker, F. Allegrini, W. S. Kurth, S. J. Bolton
Summary: Juno observed a clear decrease in magnetic field amplitude and an enhancement of energetic electron fluxes in the plasma sheet near Jupiter's magnetic equator during its first 29 orbits. In the outer radiation belt, Juno observed pancake-shaped electron distributions with high fluxes at approximately 90 degrees pitch angle and whistler-mode waves. The electron phase space density gradients suggest the dominant role of adiabatic radial transport at higher magnetic field shells, and possible loss processes at lower magnetic field shells.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Chemistry, Physical
Mathias Poline, Arnaud Dochain, Stefan Rosen, Jon Grumer, MingChao Ji, Gustav Eklund, Ansgar Simonsson, Peter Reinhed, Mikael Blom, Nicholas S. Shuman, Shaun G. Ard, Albert A. Viggiano, Mats Larsson, Henrik Cederquist, Henning T. Schmidt, Henning Zettergren, Xavier Urbain, Paul S. Barklem, Richard D. Thomas
Summary: The mutual neutralisation of O+ with O- was studied at different collision energies and found to be consistent with previous experimental results. Previously unidentified spectral features related to the first metastable state of O+ were discovered. Theoretical calculations were able to predict several experimentally observed channels, but had limitations in describing all observed contributions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Astronomy & Astrophysics
Sina Sadeghzadeh, Jian Yang, Chih-Ping Wang, Ameneh Mousavi, Wenrui Wang, Weiqin Sun, Frank Toffoletto, Richard Wolf
Summary: The study confirms the essential role of bursty bulk flows, known as bubbles, in mass and energy transport, as well as in resolving the pressure balance crisis in the plasma sheet. Comparisons against observational data reveal that the injections of bubbles have significant effects on the average configuration of the plasma sheet.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Engineering, Aerospace
R. P. Aswathy, G. Manju
Summary: The study demonstrates the direct impact of Equatorial Ionization Anomaly (EIA) crest magnitude on the base height of post sunset ionospheric F-layer, influencing the day-to-day control of ionospheric plasma irregularities. Under strong (weak) EIA crest conditions, equatorial spread F irregularities are observed to appear earlier (later) and have a longer (shorter) duration.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Astronomy & Astrophysics
Ross Pallister, Natasha L. S. Jeffrey
Summary: This study investigates the mechanism and location of solar flare electron acceleration through modeling and observations. The research finds that cold, dense coronal regions significantly affect the observed electron spectra, and this effect is correlated with the temperature and density of plasma in the region.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Fluids & Plasmas
Baofeng Gao, Huishan Cai, Xiang Gao, Yuanxi Wan
Summary: The influence of circulating energetic ions (CEIs) on double tearing mode (DTM) was studied using a global kinetic-MHD hybrid simulation. It was found that CEIs with small orbit width destabilize the DTM, but their destabilizing effect decreases as the orbit width increases. When the orbit width is large enough, the DTM transitions to single tearing modes, making the mode more stable.
Review
Biochemistry & Molecular Biology
Jin-Yan Zhou, Dong-Li Hao, Guang-Zhe Yang
Summary: This review focuses on seven types of proteins crucial for cytosolic pH homeostasis in plants, detailing their functions, regulation, and impact on cellular pH balance. Different protein types play distinct roles in regulating cytosolic pH, contributing to overall cellular homeostasis.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Editorial Material
Geosciences, Multidisciplinary
P. Alken, E. Thebault, C. D. Beggan, M. Nose
EARTH PLANETS AND SPACE
(2022)
Article
Astronomy & Astrophysics
A. Keiling, C. Ramos, N. Vu, V. Angelopoulos, M. Nose
Summary: Substorm activity exhibits two preferred recurrent intervals, with the longer interval extensively studied and the shorter interval not addressed. Statistical analysis shows that the 1-hour events are a nonstorm phenomenon, distinguishing them from sawtooth events. While sharing statistical similarities with isolated substorms, our events also include pseudo-breakups and smaller substorm activations.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
M. Teramoto, Y. Miyoshi, A. Matsuoka, Y. Kasahara, A. Kumamoto, F. Tsuchiya, M. Nose, S. Imajo, M. Shoji, S. Nakamura, M. Kitahara, I. Shnohara
Summary: Using magnetic field and electron density data from the Arase satellite, this study investigates the spatial properties of Pi2 pulsations in relation to the plasmapause in the inner magnetosphere. The results show that high-coherence magnetic field disturbances are mainly identified in the radial and compressional components on the nightside in the pre-midnight sector. By determining the location of the plasmapause using electron densities, it is found that the high-coherence events exhibit specific power ratio and phase changes near the plasmapause, indicating excitation by the plasmaspheric virtual resonance mode on the nightside.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
K. Keika, S. Kasahara, S. Yokota, M. Hoshino, K. Seki, T. Amano, L. M. Kistler, M. Nose, Y. Miyoshi, T. Hori, I. Shinohara
Summary: During magnetic storms, O+ ions play a significant role in plasma pressure in the inner magnetosphere. Heavier ions are more energized than lighter ions, and lower-charge-state ions are more energized than higher-charge-state ions. The preferential energization is due to temperature increases rather than the generation of energetic ions in the high-energy tail.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
S. Ohtani, T. Motoba, J. W. Gjerloev, H. U. Frey, I. R. Mann, P. J. Chi, H. Korth
Summary: In this study, we investigated the spatio-temporal development of auroral electrojets before auroral breakup in three substorm events. The results showed that in two events, the auroral breakup was associated with equatorward motion of an auroral form and changes in the ground magnetic field. However, in the third event, no clear equatorward flow was observed. These findings suggest that the braking of a pre-onset earthward flow burst is not the direct cause of substorm onset.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Yuki Nakamura, Koichiro Terada, Chihiro Tao, Naoki Terada, Yasumasa Kasaba, Francois Leblanc, Hajime Kita, Aoi Nakamizo, Akimasa Yoshikawa, Shinichi Ohtani, Fuminori Tsuchiya, Masato Kagitani, Takeshi Sakanoi, Go Murakami, Kazuo Yoshioka, Tomoki Kimura, Atsushi Yamazaki, Ichiro Yoshikawa
Summary: The study evaluates the contribution of meteoric ions to ionospheric conductance by developing an ionospheric model combining a meteoroid ablation model and a photochemical model. It finds that the largest contribution to Pedersen and Hall conductivities occurs in the meteoric ion layer at altitudes of 350-600 km due to the long lifetimes of meteoric ions. Including meteoric ions enhances Pedersen and Hall conductances by factors of 3 and 10 in different regions, impacting magnetospheric plasma convection.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
T. Sakurai, A. N. Wright, K. Takahashi, T. Elsden, Y. Ebihara, N. Sato, A. Kadokura, Y. Tanaka, T. Hori
Summary: A one-to-one correspondence is found between poleward moving auroral arcs (PMAAs) and H-component of magnetic field Pc5 oscillations. PMAAs are most prominent at a magnetic latitude of 69 degrees and exhibit features of field-line resonances. Ground-based Pc5 oscillations are observed concurrently with toroidal mode Pc5 oscillations observed by THEMIS satellites. Numerical modeling shows that the magnetic energy of Pc5 oscillations is much larger than the kinetic energy, indicating the importance of magnetic energy in producing auroral emissions in the ionosphere.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Shinichi Ohtani
Summary: This study investigates the cause of a horizontal magnetic field depression observed during the 2003 Halloween storm and compares it with the magnetic depression observed during the 1859 Carrington storm. The findings suggest that the cause of these depressions may be a wedge current system driven by daytime magnetic reconnection.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Khan-Hyuk Kim, Kazue Takahashi, Junhyun Lee, Ho Jin, Jong-Woo Kwon
Summary: Van Allen Probe A observed strongly enhanced hydrogen (H+) band electromagnetic ion cyclotron (EMIC) waves lasting >6 hr without helium (He+) band EMIC wave activity outside the plasmasphere on 23 February 2014. During the H-band EMIC wave interval, multiharmonic toroidal waves were detected by the spacecraft. The study suggests that the cold ion composition plays a major role in determining the spectral properties of EMIC waves and discusses the energization of low-energy He+ ions in the perpendicular direction.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Kazue Takahashi, Robert Lysak, Massimo Vellante
Summary: In this study, spatial maps of magnetospheric oscillations coherent with ground Pi2 pulsations were generated statistically, allowing for the determination of the mode structure of Pi2 pulsation in the inner magnetosphere. The results show higher coherence of the poloidal components and confirm the cavity mode nature of Pi2 pulsations.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
S. Ohtani, T. Motoba
Summary: This study examines the formation and propagation of auroral beads by analyzing ground all-sky images. The results show that the expansion and propagation of auroral beads are independent of the preceding equatorward flow and can occur in either eastward or westward direction. The development of auroral beads does not affect nearby arcs and two wavy arcs can propagate in different directions. The study suggests that the magnetosphere-ionosphere coupling plays a crucial role in the development of auroral beads.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Geochemistry & Geophysics
A. V. Rubtsov, M. Nose, A. Matsuoka, Y. Kasahara, A. Kumamoto, F. Tsuchiya, I. Shinohara, Y. Miyoshi
Summary: The radial distribution of ion mass density in the Earth's magnetosphere can differ from that of electrons when there is a localized enhancement of heavy ion flux, such as an oxygen torus. This difference is crucial for the study of ultra-low-frequency (ULF) waves, which rely on the Alfven velocity and mass density. One important consequence is the shift in the location of the plasmapause, which is considered as the resonator and generation area for ULF waves. In this study, we identified that a factor of 1.65 or more increase in the Alfven velocity within a radial distance of 0.5 RE corresponds to the classic definition of plasmapause, where the electron density drops by a factor of 5 or more within the same radial distance. This finding allows us to confidently use the Alfven velocity to detect the plasmapause even when heavier ions are included and a direct comparison with electron density is not possible.
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
(2023)
Article
Astronomy & Astrophysics
Kazue Takahashi, Tom Elsden, Andrew N. Wright, Alexander W. Degeling
Summary: Previous studies have found that magnetospheric ultralow frequency waves excited by interplanetary shocks have a strong toroidal component, indicating azimuthal displacement of magnetic field lines. However, observations of toroidal oscillations on the dayside by multiple spacecraft during an interplanetary shock event on 27 February 2014 revealed a strong poloidal component as well (radial field line displacement). Simulation results showed that the poloidal component is due to radially standing fast mode waves, while the toroidal component is a result of field line resonance driven by the fast mode waves, and their relative amplitudes and phases change with radial distance.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
A. V. Rubtsov, M. Nose, A. Matsuoka, I. Shinohara, Y. Miyoshi
Summary: This study presents a statistical analysis of Pc4 and Pc5 waves in the Earth's magnetosphere, revealing their polarization interactions and spatial distribution features. The results show that toroidal and poloidal waves are associated with external and internal sources, respectively, while compressional waves are observed only in the equatorial region. Surprisingly, the statistics of wave polarization exhibit a normal distribution without separate clusters, suggesting the prevalence of polarization change and mode coupling processes. This finding is important for understanding the energy exchange mechanism between waves and charged particles in the magnetosphere.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
A. V. Rubtsov, M. Nose, A. Matsuoka, Y. Kasahara, A. Kumamoto, F. Tsuchiya, I. Shinohara, Y. Miyoshi
Summary: Magnetic storms and substorms cause global disturbances in the Earth's magnetosphere. Plasma clouds injected from the magnetotail during storm or substorm drift around the Earth and generate ultra-low frequency (ULF) waves via various mechanisms. The plasmasphere and its boundary, plasmapause, are special regions for ULF waves to interact with charged particles.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
