Search Publications
Global-scale magnetosphere convection driven by dayside magnetic reconnection
Branduardi-Raymont, Graziella; Wang, Chi; Dai, Lei +8 more
Plasma convection on a global scale is a fundamental feature of planetary magnetosphere. The Dungey cycle explains that steady-state convection within the closed part of the magnetosphere relies on magnetic reconnection in the nightside magnetospheric tail. Nevertheless, time-dependent models of the Dungey cycle suggest an alternative scenario whe…
Solar Wind Current Sheets: MVA Inaccuracy and Recommended Single-Spacecraft Methodology
Wang, R.; Phan, T. D.; Mozer, F. S. +1 more
We present the analysis of 1,831 current sheets (CS) observed aboard four Cluster spacecraft in a pristine solar wind. Four-spacecraft estimates of the CS normal and propagation velocity are compared with different single-spacecraft estimates. The Minimum Variance Analysis (MVA) of the magnetic field is shown to be highly inaccurate in estimating …
Magnetic Reconnection at Planetary Bodies and Astrospheres
Stawarz, Julia E.; Phan, Tai D.; Harada, Yuki +11 more
Magnetic reconnection is a fundamental mechanism for the transport of mass and energy in planetary magnetospheres and astrospheres. While the process of reconnection is itself ubiquitous across a multitude of systems, the techniques used for its analysis can vary across scientific disciplines. Here we frame the latest understanding of reconnection…
Global-Scale Processes and Effects of Magnetic Reconnection on the Geospace Environment
Eastwood, J. P.; Lavraud, B.; Nakamura, R. +14 more
Recent multi-point measurements, in particular from the Magnetospheric Multiscale (MMS) spacecraft, have advanced the understanding of micro-scale aspects of magnetic reconnection. In addition, the MMS mission, as part of the Heliospheric System Observatory, combined with recent advances in global magnetospheric modeling, have furthered the unders…
Small-amplitude Compressible Magnetohydrodynamic Turbulence Modulated by Collisionless Damping in Earth's Magnetosheath: Observation Matches Theory
Liu, Terry Z.; Zhao, Siqi; Yan, Huirong +2 more
Plasma turbulence is a ubiquitous dynamical process that transfers energy across many spatial and temporal scales and affects energetic particle transport. Recent advances in the understanding of compressible magnetohydrodynamic (MHD) turbulence demonstrate the important role of damping in shaping energy distributions on small scales, yet its obse…
New Chorus Diffusion Coefficients for Radiation Belt Modeling
Meredith, Nigel P.; Wong, Jin-Mann; Horne, Richard B. +2 more
Whistler mode chorus is an important magnetospheric wave emission playing a major role in radiation belt dynamics, where it contributes to both the acceleration and loss of relativistic electrons. In this study we compute bounce and drift averaged chorus diffusion coefficients for 3.0 < L* < 6.0, using the TS04 external magnetic field model,…
What is the Reynolds Number of the Solar Wind?
Wrench, Daniel; Parashar, Tulasi N.; Oughton, Sean +2 more
The Reynolds number, Re, is an important quantity for describing a turbulent flow. It tells us about the bandwidth over which energy can cascade from large scales to smaller ones, prior to the onset of dissipation. However, calculating it for nearly collisionless plasmas like the solar wind is challenging. Previous studies have used formulations o…
Upstream Plasma Waves and Downstream Magnetic Reconnection at a Reforming Quasi-parallel Shock
Yang, Zhongwei; Lu, Quanming; Gao, Xinliang +4 more
With the help of a two-dimensional particle-in-cell simulation model, we investigate the long-time evolution (near $100{{\rm{\Omega }}}_{i0}^{-1}$ , where Ω i0 is the ion gyrofrequency in the upstream) of a quasi-parallel shock. Some of the upstream ions are reflected by the shock front, and their interactions with the incident ions exc…
Storm-Time Very-Near-Earth Magnetotail Reconnection: A Statistical Perspective
Angelopoulos, V.; Beyene, F.
The ring current, an equatorial near-Earth current, fluctuates in response to solar wind plasma interactions with Earth's magnetosphere. Despite extensive research on storm-time ring current energization, direct evidence of the energy transport into the inner-magnetosphere that powers this current remains scarce. Recent observations revealing that…
Key Factors Determining Nightside Energetic Electron Losses Driven by Whistler-Mode Waves
Ma, Qianli; Zhang, Xiao-Jia; Agapitov, Oleksiy +4 more
Energetic electron losses by pitch-angle scattering and precipitation to the atmosphere from the radiation belts are controlled, to a great extent, by resonant wave particle interactions with whistler-mode waves. The efficacy of such precipitation is primarily modulated by wave intensity, although its relative importance, compared to other wave an…