Article
Astronomy & Astrophysics
Alexander Shane, Michael Liemohn
Summary: The study investigates the conditions for the energization process of high-energy superthermal electrons on the dayside crustal magnetic fields at Mars. By calculating characteristic energy profiles and wave parameters, it was found that wave-particle interactions are more efficient than Coulomb collisions in modifying the pitch angle distribution of electrons.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Mathematics, Applied
David A. Kopriva, Gregor J. Gassner, Jan Nordstrom
Summary: The paper discusses using the behavior of the L-2 norm to infer stability of discontinuous Galerkin spectral element methods for linear hyperbolic equations. By utilizing an upwind numerical flux that satisfies the Rankine-Hugoniot condition, the DGSEM is shown to have the same energy bound in the L-2 norm as the partial differential equation, with added dissipation depending on the approximation error.
JOURNAL OF SCIENTIFIC COMPUTING
(2021)
Article
Physics, Multidisciplinary
A. Potylitsyn, G. Kube, A. Novokshonov, A. Vukolov, S. Gogolev, B. Alexeev, P. Klag, W. Lauth
Summary: The study summarizes the spectral properties of optical Cherenkov radiation, demonstrating the observation of quasi-monochromatic radiation through exploiting the frequency dependency. Experimental results confirm the theoretical model predictions, showing satisfactory agreement. The monochromatization mechanism could potentially be applied in beam diagnostics at modern particle accelerators.
Article
Astronomy & Astrophysics
Qi Zhu, Xing Cao, Binbin Ni, Xudong Gu, Xin Ma
Summary: This study investigates the effects of hot protons on the scattering loss of ring current protons induced by electromagnetic ion cyclotron (EMIC) waves, by calculating the proton bounce-averaged pitch angle diffusion coefficients. The results show that inclusion of hot protons significantly decreases the diffusion coefficients of low-energy protons, while increasing the scattering efficiency of high-energy protons at certain angles. The cold plasma approximation underestimates the loss timescales of low-energy protons but overestimates that of high-energy protons. The differences in proton loss timescales caused by hot protons depend on the hot proton concentration, temperature anisotropy, and L-shell.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Mathematics, Applied
Jiansheng Geng, Xiufang Ren, Yingfei Yi
Summary: In this paper, we study the one-dimensional, quasi-periodically forced, linear KdV equations and obtain results on the reducibility of the equations and the existence and stability of solutions.
JOURNAL OF DYNAMICS AND DIFFERENTIAL EQUATIONS
(2022)
Article
Computer Science, Interdisciplinary Applications
Scott O'Connor, Zane D. Crawford, O. H. Ramachandran, John Luginsland, B. Shanker
Summary: The development of particle-in-cell (PIC) methods using finite element based methods has gained renewed interest due to their ability to better model geometry and understand function spaces necessary to represent Maxwell quantities. Recent methods have been developed to satisfy these equations while being agnostic to time stepping methods. However, implicit finite element transient solvers have a drawback of producing spurious charge, while explicit schemes are conditionally stable with small time step sizes that are mesh dependent. A quasiHelmholtz formulation on a tessellation can overcome these limitations and satisfy all four Maxwell's equations, as demonstrated by analyzing specific examples.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Geosciences, Multidisciplinary
S. Toledo-Redondo, J. H. Lee, S. K. Vines, D. L. Turner, R. C. Allen, M. Andre, S. A. Boardsen, J. L. Burch, R. E. Denton, H. S. Fu, S. A. Fuselier, D. J. Gershman, B. Giles, D. B. Graham, N. Kitamura, Yu. V. Khotyaintsev, B. Lavraud, O. Le Contel, W. Y. Li, T. E. Moore, E. A. Navarro, J. Porti, A. Salinas, A. Vinas
Summary: The study reports observations of ion dynamics within an Alfven branch wave near the dayside magnetopause, with measurements consistent with a dispersion solver's predictions. The magnetospheric plasma includes hot protons, cold protons, and heavy ions, showing how cold protons exchange energy adiabatically with the wave fields. Increasing cold proton density facilitates wave propagation and amplification, particularly at oblique angles, as observed.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Xiongdong Yu, Zhigang Yuan, Zuxiang Xue
Summary: This study investigates the generation mechanism of second harmonics in magnetospheric waves using wave equations and kinetic theory approach. Hybrid simulations are conducted to validate the theoretical results, revealing the important role of linear dispersion relation in second harmonic generation.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Physics, Fluids & Plasmas
Alvaro Sanchez-Villar, Jiewei Zhou, Eduardo Ahedo, Mario Merino
Summary: A numerical simulation was conducted on an electron-cyclotron resonance thruster (ECRT) prototype, showing good agreement with experimental data. The plasma discharge in ECRT is influenced by plasma density and applied magnetic field, resulting in multiple electromagnetic field propagation/evanescence regimes. Power absorption is mainly driven by radial fast electric fields in the electron-cyclotron resonance region, with large cross-field electron temperature gradients observed.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Astronomy & Astrophysics
Kyungguk Min, Kaijun Liu
Summary: This study investigates proton scattering by equatorial fast magnetosonic waves with varying wave normal angles including 90 degrees, using test-particle calculations and quasilinear theory. The results show that the quasilinear diffusion coefficients due to MSWs are consistent with those estimated from the test-particle approach up to 90 degrees WNA. The test-particle dynamics at 90 degrees WNA reveal the importance of slightly off-integer harmonic frequencies in making the proton scattering stochastic.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
C. M. Espinoza, P. S. Moya, M. Stepanova, J. A. Valdivia, R. E. Navarro
Summary: Understanding the relaxation processes and turbulence states in plasma physics is a fundamental challenge. Recent studies suggest that similar mechanisms regulate the plasma in both solar wind and Earth's magnetotail, indicating the universality of spontaneous fluctuation and collisionless regulation in space and astrophysical plasmas.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Fluids & Plasmas
P. S. Moya, M. Lazar, S. Poedts
Summary: This study focuses on the evolution of anisotropic bi-Kappa distributions, showing that the kappa parameter may vary during the relaxation of temperature anisotropy, ultimately leading to the suprathermalization of the plasma. The variation of kappa depends on the initial conditions of anisotropic electrons, which can vary significantly in the inner heliosphere.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Engineering, Electrical & Electronic
Mohammed K. M. Elhabbash, Mohd Mahadi Halim, Tiem Leong Yoon
Summary: This study utilizes a polynomial approach to simulate the optical-electrical response of a multilayer thin film under an applied transverse voltage. Each layer in the film is modeled as a capacitor coupled to the next, and the electric charges at the interface between adjacent layers can be modulated by the transverse voltage. Numerical results from the simulation demonstrate the convenient prediction of non-trivial optical responses, providing a handy tool for designing and optimizing the optical functionality of multilayer thin films.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Geochemistry & Geophysics
Guoqiang Xue, Yiming He, Weiying Chen, Xin Wu, Wanting Song
Summary: The short offset transient electromagnetic method (SOTEM) is widely used in coal hydrogeology investigations and mineral explorations due to its advantages of high precision, large depth abilities, and high efficiency. However, the computational complexity and memory requirements for 3-D SOTEM inversion algorithms have made it challenging to meet fine detection requirements under complex geological conditions. In this study, a particle swarm optimization-quasi-Newton hybrid algorithm (PSO-QN) was proposed to achieve high precision and fast 3-D inversions of SOTEM data. The results demonstrated that the proposed inversion method had a strong anti-noise capacity, high speed, good stability, and high resolution.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Engineering, Electrical & Electronic
Mohammed K. M. Elhabbash, Mohd Mahadi Halim, Tiem Leong Yoon, Sofyan A. Taya
Summary: In this study, the electrical and optical response of a multilayer thin film composed of lossless and lossy materials in an alternating arrangement under a transverse voltage is simulated using a polynomial approach. The model treats the multilayer thin film as an effective capacitor constructed from coupled capacitors, with the interface between layers representing the coupling. By adjusting the transverse electric potential, the model can predict nontrivial optical responses.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Geosciences, Multidisciplinary
YuMing Wang, TieLong Zhang, GuoQiang Wang, SuDong Xiao, ZhuXuan Zou, Long Cheng, ZongHao Pan, Kai Liu, XinJun Hao, YiRen Li, ManMing Chen, ZhouBin Zhang, Wei Yan, ZhenPeng Su, ZhiYong Wu, ChengLong Shen, YuTian Chi, MengJiao Xu, JingNan Guo, Yang Du
Summary: The Mars Orbiter MAGnetometer (MOMAG) is a scientific instrument on China's Tianwen-1 mission, recording magnetic field data around Mars. It shows similar magnetic structures and magnitudes as NASA's MAVEN mission, with 158 clear bow shock crossings matching the modeled average. Comparing datasets from Tianwen-1 and MAVEN confirms the global shape and south-north asymmetry of the Martian bow shock. MOMAG performs well, providing accurate magnetic field vectors, and its data complements MAVEN to enhance our understanding of the plasma environment of Mars.
EARTH AND PLANETARY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Xiaolei Li, Yuming Wang, Fang Shen, Yi Yang, Quanhao Zhang, Shaoyu Lyu
Summary: We developed a correlation-aided reconstruction method to recognize and locate solar wind transients observed by the Heliospheric Imager-1 (HI1) and inferred their radial velocity distribution. By applying this method to small-scale transients in a complete Carrington rotation, we successfully reconstructed a synoptic map of the solar wind radial velocity. Our test suggests that the reconstructed synoptic map matches the preset synthetic transients in terms of latitude, longitude, and radial velocity.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Rongsheng Wang, Xiancai Yu, Yuming Wang, Quanming Lu, San Lu
Summary: Several thin current layers were detected in the rear boundary of an interplanetary coronal mass ejection (ICME) observed by the Parker Solar Probe spacecraft. These currents layers were caused by the interaction between the background solar wind and the rear boundary of the ICME. The observations suggest that fast Hall magnetic reconnection can occur as close as 56 solar radii from the Sun and plays a crucial role in ICME evolution.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Zhenjun Zhou, Chaowei Jiang, Hongqiang Song, Yuming Wang, Yongqiang Hao, Jun Cui
Summary: Solar filament eruptions show complex geometric deformation, and the development of writhe during the eruption has been quantitatively investigated. The analysis reveals that the writhe number of the filament axes decreases and reaches large negative values, indicating a conversion of twist into writhe during the eruption.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Zhenpeng Su, Yuming Wang, Tielong Zhang, Zhiyong Wu, Long Cheng, Zhuxuan Zou, Chenglong Shen, Jingnan Guo, Sudong Xiao, Guoqiang Wang, Zonghao Pan, Kai Liu, Xinjun Hao, Yiren Li, Manming Chen, Yutian Chi, Mengjiao Xu
Summary: We present the first observation of significant modifications by a solar wind stream interaction region to the Martian foreshock waves, which are an important energy dissipation product of the bow shock.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Jiajia Liu, Anchuan Song, David B. Jess, Jie Zhang, Mihalis Mathioudakis, Szabolcs Soos, Francis P. Keenan, Yuming Wang, Robertus Erdelyi
Summary: This paper presents a newly developed semi-automated jet identification algorithm, which is applied to detect over 1200 off-limb solar jets. Power-law distributions are found between the intensity/energy and frequency of these events, with indices similar to those for flares and coronal mass ejections (CMEs). These jets are modulated by the solar cycle and exhibit latitudinal-temporal evolution, quasi-annual oscillations, and clustering in certain active longitudinal belts. The results suggest that coronal jets share the same nonlinear statistics of scale-free processes as flares and CMEs in different scales of eruptive events.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Geosciences, Multidisciplinary
Zhiyong Wu, Zhenpeng Su, Huinan Zheng, Yuming Wang
Summary: Magnetosonic waves inside and outside the plasmasphere differ statistically in occurrence rate, frequency, and intensity. How the density interface separates magnetosonic waves inside and outside the plasmasphere remains not fully understood.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Xu Wang, Chaoling Tang, Binbin Ni, Zhengpeng Su, Jichun Zhang, Jingrun Chen, Xinxin Chu
Summary: Using Van Allen Probes data, the authors studied the evolution of seed and relativistic electrons in Earth's outer radiation belt during storms. They classified storm events into moderate and short (MS), moderate and long (ML), strong and short (SS), and strong and long (SL) based on storm intensity and duration. They found that the duration of the main phase and storm intensity are important for the evolution of electron fluxes in the radiation belt during storms.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Yutian Chi, Chenglong Shen, Junyan Liu, Zhihui Zhong, Mathew Owens, Christopher Scott, Luke Barnard, Bingkun Yu, Daniel Heyner, Hans-Ulrich Auster, Ingo Richter, Yuming Wang, Tielong Zhang, Jingnan Guo, Beatriz Sanchez-Cano, Zonghao Pan, Zhuxuan Zou, Mengjiao Xu, Long Cheng, Zhenpeng Su, Dongwei Mao, Zhiyong Zhang, Can Wang, Zhiyong Wu, Guoqiang Wang, Sudong Xiao, Kai Liu, Xinjun Hao, Yiren Li, Manming Chen, Mike Lockwood
Summary: This study reports two multipoint interplanetary coronal mass ejections (ICMEs) detected by the Tianwen-1 and Mars Atmosphere and Volatile Evolution spacecraft at Mars, and the BepiColombo spacecraft upstream of Mars. The findings highlight the importance of background solar wind in determining the interplanetary evolution and global morphology of ICMEs up to Mars distance. Observations from multiple locations are invaluable for space weather studies at Mars and merit more exploration in the future.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Long Cheng, Robert Lillis, Yuming Wang, Anna Mittelholz, Shaosui Xu, David L. L. Mitchell, Catherine Johnson, Zhenpeng Su, Jasper S. S. Halekas, Benoit Langlais, Tielong Zhang, Guoqiang Wang, Sudong Xiao, Zhuxuan Zou, Zhiyong Wu, Yutian Chi, Zonghao Pan, Kai Liu, Xinjun Hao, Yiren Li, Manming Chen, Jared Espley, Frank Eparvier
Summary: This study presents direct evidence of solar wind effects on the Martian bow shock based on the analysis of Tianwen-1 and MAVEN data. The results show that the bow shock is rapidly compressed and expanded during the dynamic pressure pulse in the solar wind and oscillated during the IMF rotation. The superposition of variations in multiple solar wind parameters leads to more intensive bow shock oscillation. This study emphasizes the importance of joint observations by Tianwen-1 and MAVEN for studying the real-time response of the Martian magnetosphere to the solar wind.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Jingnan Guo, Xiaolei Li, Jian Zhang, Mikhail I. Dobynde, Yuming Wang, Zigong Xu, Thomas Berger, Jordanka Semkova, Robert F. Wimmer-Schweingruber, Donald M. Hassler, Cary Zeitlin, Bent Ehresmann, Daniel Matthiae, Bin Zhuang
Summary: On 28 October 2021, solar eruptions caused intense and long-lasting enhancements in solar energetic particle (SEP) flux observed by spacecraft across the heliosphere. The arrival of SEPs at Earth resulted in the 73rd ground level enhancement (GLE) event recorded by ground-based neutron monitors. Notably, this study presents the first GLE event detected on the surfaces of Earth, Moon, and Mars, using particle and radiation detectors. By analyzing data from near-Earth spacecraft, the event-integrated proton spectrum is determined, and particle transport models are employed to predict radiation levels on the lunar and martian surfaces. Additionally, previous GLE event doses on the Moon and Mars are modeled and compared with the current event, contributing to our understanding of potential radiation risks for future human exploration of these celestial bodies.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Nigang Liu, Zhenpeng Su, Yuyue Jin, Zhaoguo He, Jiang Yu, Kun Li, Zuzheng Chen, Jun Cui
Summary: Auroral brightening on Earth's closed magnetic field lines is commonly attributed to electron precipitations by electron cyclotron harmonic waves and whistler-mode chorus waves in the low-density region. However, we propose that high-frequency whistlers in the high-density plasmasphere can also drive auroral activity. Theoretical calculations and observations following an interplanetary shock support the existence of these high-frequency whistler-mode waves inside the plasmasphere. Our findings demonstrate the significant role of interplanetary shocks in promoting energy transfer from the inner high-density magnetosphere to the ionosphere.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Xu Shan, Bin Miao, Zhe Cao, Zhenyu Sun, Yiren Li, Kai Liu, Sanbiao Qu, Xingyu Guo, Zhenpeng Su, Chenglong Shen, Zonghao Pan, Xin Li, Xinjun Hao, Xiaoping Yang, Chao Tian, Yu Jiang, Shubin Liu, Qi An, Xiangjun Chen, Yuming Wang
Summary: A low-energy ion spectrometer (LEIS) on a Chinese navigation satellite can detect plasma using a top-hat electrostatic analyzer and angular scanning deflectors. It can measure energetic ions in 3D space with a wide field of view and energy range. Performance parameters such as geometric factor, resolution, and linear relations between angles and voltages have been determined through simulations and experiments, and the LEIS has been shown to meet mission requirements.