Search Publications
Investigating Whistler-Mode Wave Intensity Along Field Lines Using Electron Precipitation Measurements
Zhang, Xiao-Jia; Angelopoulos, Vassilis; Tsai, Ethan +1 more
Electron fluxes in Earth's radiation belts are significantly affected by their resonant interaction with whistler-mode waves. This wave-particle interaction often occurs via first cyclotron resonance and, when intense and nonlinear, can accelerate subrelativistic electrons to relativistic energies while also scattering them into the atmospheric lo…
Cluster Observation on the Latitudinal Distribution of Magnetic Pc5 Pulsations in the Inner Magnetosphere
Cao, Jinbin; Li, Xinlin; Liu, Wenlong +4 more
Ultralow frequency (ULF) waves in the Pc5 band are ubiquitous in the inner magnetosphere and can impact radiation belt dynamics by interacting with electrons through drift or drift-bounce resonance. In this paper, based on ∼ 19 years of Cluster measurements, we perform a comprehensive study of the three-dimensional distribution of poloidal, toroid…
Ring Current Morphology From MMS Observations
Russell, C. T.; Dunlop, M. W.; Shen, C. +5 more
We directly estimate the in situ current density of the Earth's ring current (RC) using the curlometer method and investigate its morphology using the small spatial separations and high accuracy of the Magnetospheric Multiscale mission. Through statistical analysis of data from September 2015 to the end of 2016, covering the region of 2-8 RE<…
Field Gradient Analysis Based on a Geometrical Approach
Dunlop, M.; Shen, C.
Using multi-point observations from a spacecraft constellation, the spatial gradients of measured physical quantities can be calculated, and thus other derived parameters for the plasma (e.g., current density, topology of magnetic field lines, and wave vectors) can also be calculated. In this research, a geometrical method based on integral theore…
Cassini Radio Occultation Observations of Saturn's Ionosphere: Electron Density Profiles From 2005 to 2013
Withers, Paul; Dalba, P. A.; Moore, L. +2 more
A set of electron density profiles of Saturn's ionosphere acquired by Cassini radio occultations is archived at the NASA Planetary Data System. However, the reference surface that defines zero altitude in these profiles is unknown and appears to vary by 1,500 km at fixed latitude. These profiles are immensely valuable for addressing questions pert…
Statistical Study of Release Time and Its Energy Dependence of In Situ Energetic Electrons in Impulsive Solar Flares
Li, Gang; Wang, Linghua; Zhao, Lulu +3 more
Using the fraction velocity dispersion analysis method, it has been shown recently that in two impulsive solar energetic electron (SEE) events, the release times of near-relativistic electrons at the Sun for outward-propagating electrons are energy dependent and are delayed compared to those of the downward-propagating electrons. In this work, we …
Propagation of the Interplanetary Shock Induced Pulse: New Observations by the Global Navigation Satellite System
Zong, Qiugang; Zhang, Hui; Chen, Xingran +3 more
We revisited a typical interplanetary (IP) shock event on 7 November 2004, with high time resolution (1 s) total electron content (TEC) observations. The IP shock impinged on the dayside magnetopause at ∼18:27 UT, and launched a pulse into the magnetosphere. Using the multi-spacecraft timing method, the pulse was estimated to propagate at an angul…
Data-Based Modeling of the Magnetosheath Magnetic Field
Semenov, V. S.; Erkaev, N. V.; Tsyganenko, N. A.
A quantitative model of the magnetosheath (MS) magnetic structure is developed, using a multi-year set of Geotail, Themis, Cluster, and MMS magnetometer and plasma instrument data. The MS database is created using an identification algorithm, based on observed magnetic field magnitudes and proton densities, normalized by their concurrent interplan…
Statistical Mapping of Magnetic Topology at Venus
Persson, Moa; Xu, Shaosui; Frahm, Rudy A. +3 more
Despite Venus having insignificant intrinsic magnetic fields, the magnetic connectivity between the solar wind and the Venus ionosphere, or magnetic topology, is not as simple as expected and is also important for characterizing the Venus space environment. This study provides a technique combining superthermal electron energy and pitch angle dist…
Solar Wind Protons Forming Partial Ring Distributions at Comet 67P
Gunell, H.; Nilsson, H.; Richter, I. +5 more
We present partial ring distributions of solar wind protons observed by the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko. The formation of ring distributions is usually associated with high activity comets, where the spatial scales are larger than multiple ion gyroradii. Our observations are made at a low-activity comet at a heliocentric …