Search Publications
The Effect of Current on Magnetic Null Topology during Turbulent Reconnection
Wang, Z.; Cao, J. B.; Liu, Y. Y. +5 more
Using data from the Cluster mission and the First-Order Taylor Expansion method, we investigate the spiral magnetic nulls nested in the diffusion region of turbulent reconnection in the magnetotail. We particularly focus on the relation between the magnetic null topologies and currents, which can be decomposed into a component perpendicular to spi…
Strategies for Determining the Cascade Rate in MHD Turbulence: Isotropy, Anisotropy, and Spacecraft Sampling
Shay, Michael A.; Oughton, Sean; Yang, Yan +6 more
Exact laws for evaluating cascade rates, tracing back to the Kolmogorov "4/5" law, have been extended to many systems of interest including magnetohydrodynamics (MHD), and compressible flows of the magnetofluid and ordinary fluid types. It is understood that implementations may be limited by the quantity of available data and by the lack of turbul…
High-frequency Magnetic Fluctuations in Space Plasmas and the Role of Electron Landau Damping
Telloni, Daniele; Vecchio, Antonio; Lepreti, Fabio +1 more
While low-frequency plasma fluctuations in the interplanetary space have been successfully described in the framework of classical turbulence, high-frequency fluctuations still represent a challenge for theoretical models. At these scales, kinetic plasma processes are at work, but although some of them have been identified in spacecraft measuremen…
Statistical Analysis of the Distribution and Evolution of Mirror Structures in the Martian Magnetosheath
Jin, Taifeng; Lei, Li; Yiteng, Zhang +2 more
The mirror-mode structures in the Martian magnetosheath that were observed by Mars Atmosphere and Volatile Evolution during 2015-2018 are analyzed statistically. It is found that most mirror-mode events occurred close to the bow shock. Morphological categorization based on skewness of the magnetic field shows that ~46.57% of the observed mirror-mo…
A Highway for Atmospheric Ion Escape from Earth during the Impact of an Interplanetary Coronal Mass Ejection
Zong, Qiugang; Xie, Lun; Zhang, Hui +9 more
A single satellite hardly measures the overall ion escape rate from a planet. Therefore, the question concerning the long-term atmospheric evolution of whether a planetary magnetic field protects its atmosphere or aggravates atmospheric loss remains unresolved. Here, combined data from multiple platforms including Cluster, DMSP, IMAGE, and Polar s…
A Volumetric Study of Flux Transfer Events at the Dayside Magnetopause
Strugarek, Antoine; Vaidya, Bhargav; Paul, Arghyadeep
Localized magnetic reconnection at the dayside magnetopause leads to the production of Flux Transfer Events (FTEs). The magnetic fields within the FTEs exhibit complex helical flux-rope topologies. Leveraging the adaptive mesh refinement strategy, we perform a three-dimensional magnetohydrodynamic simulation of the magnetosphere of an Earth-like p…
Spatial Distribution and Low-frequency Disturbance Modulation of Magnetosheath Ion Polytropic Index
Cao, Jinbin; Pang, Xuexia; Geng, Xiyao +6 more
We, using the Cluster data from 2001 to 2010, studied spatial distribution of the ion polytropic index in the magnetosheath, and the modulation of polytropic process by the low-frequency disturbances (4-18 mHz). The total of 30,3283 samples is divided into two sorts: quasi-perpendicular and quasi-parallel propagating ones. The median polytropic in…
Power Anisotropy, Dispersion Signature and Turbulence Diffusion Region in the 3D Wavenumber Domain of Space Plasma Turbulence
Verscharen, Daniel; He, Jiansen; Sahraoui, Fouad +4 more
We explore the multifaceted important features of turbulence (e.g., anisotropy, dispersion, and diffusion) in the three-dimensional (3D) wavenumber domain (k ∥, k ⊥,1, k ⊥,2), by employing the k-filtering technique to high-quality measurements of fields and particles from the Magnetospheric Multiscale Mission (MMS)…
Evidence of the Alfvén Transition Layer and Particle Precipitation in the Cusp Region: 3D Global PIC Simulation of the Solar Wind-Earth Magnetosphere Interaction
Lembège, B.; Cai, D. S.; Ekawati, Sri
A transition layer, named the Alfvénic transition layer (or ATL), has been clearly evidenced near the outer boundary of the cusp by experimental observations from the Cluster mission. This layer characterized by a local value of Log M A ~ 1, where M A is the Alfvén Mach number, allows the bulk flow to transit from super-Alfvé…
Plasma Oscillations and Kinetic Instabilities at Ion Scales in the Expanding Magnetosheath
Trávníček, Pavel M.; Chaston, Chris C.
We investigate a relationship between a decaying spectrum of magnetic field perturbations and kinetic instabilities in a slowly expanding magnetosheath plasma using two-dimensional hybrid expanding simulations in (X, Y) space. We impose an initial ambient magnetic field B 0/B 0 = (1, 0, 0), and superimpose a flat spectrum of …