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An Automatic Detection Algorithm Applied to Fast Magnetosonic Waves With Observations of the Van Allen Probes
Yuan, Zhigang; Yao, Fei; Yu, Xiongdong +2 more
Fast magnetosonic (MS) waves can play an important role in the evolution of the inner magnetosphere. However, there is still not an effective method to quantitatively identify such waves for observations of the Van Allen Probes reasonably. In this paper, we used Van Allen Probes data from 18 September 2012 to 30 September 2014 to find a more compr…
Statistical Study on Multispacecraft Widespread Solar Energetic Particle Events During Solar Cycle 24
St. Cyr, O. C.; Gopalswamy, N.; Mäkelä, P. +1 more
We conduct a statistical study on the large three-spacecraft widespread solar energetic particle (SEP) events. Longitudinal distributions of the peak intensities, onset delays, and relation between the SEP intensity, coronal mass ejection (CME) shock speed, width, and the kinetic energy of the CME have been investigated. We apply a Gaussian fit to…
Survey of Saturn's Magnetopause and Bow Shock Positions Over the Entire Cassini Mission: Boundary Statistical Properties and Exploration of Associated Upstream Conditions
Dougherty, M. K.; Thomsen, M. F.; Jackman, C. M.
The Cassini spacecraft orbited the planet Saturn from July 2004 to September 2017, and its varied orbital trajectory took it across the magnetopause and bow shock boundaries multiple times, at varying radial distances, local times, latitudes, and phases of the solar cycle. Here we present a comprehensive list of these boundary crossings, derived p…
Electron Density Profiles in the Upper Ionosphere of Mars From 11 Years of MARSIS Data: Variability Due to Seasons, Solar Cycle, and Crustal Magnetic Fields
Gurnett, D. A.; Morgan, D. D.; Halekas, J. +3 more
The Mars Advanced Radar for Subsurface and Ionosphere Sounding on board the Mars Express spacecraft measures the frequency of local plasma oscillations, which can be used to determine electron densities local to the spacecraft. This paper provides an overview of electron densities in the upper Martian ionosphere, obtained by investigating over 400…
Statistical Survey of the Terrestrial Bow Shock Observed by the Cluster Spacecraft
Maksimovic, M.; Santolik, O.; Němec, F. +6 more
The terrestrial bow shock provides us with a unique opportunity to extensively investigate properties of collisionless shocks using in situ measurements under a wide range of upstream conditions. Here we report a statistical study of 529 terrestrial bow shock crossings observed between years 2001 and 2013 by the four Cluster spacecraft. By applyin…
Numerical Algorithm for Detecting Ion Diffusion Regions in the Geomagnetic Tail With Applications to MMS Tail Season 1 May to 30 September 2017
Farrugia, C. J.; Torbert, R. B.; Rogers, A. J.
We present a numerical algorithm to identify ion diffusion regions (IDRs) in the geomagnetic tail and test its applicability. We use five criteria applied in three stages. (i) correlated reversals (within 90 s) of Vx and Bz (at least 2 nT about 0; geocentric solar magnetospheric coordinates); (ii) detection of Hall electric a…
The Storm-Time Ring Current Response to ICMEs and CIRs Using Van Allen Probe Observations
Mitchell, D. G.; Farrugia, C. J.; Kistler, L. M. +6 more
Using Van Allen Probe observations of the inner magnetosphere during geomagnetic storms driven by interplanetary coronal mass ejections (ICMEs) and corotating interaction regions (CIRs), we characterize the impact of these drivers on the storm-time ring current development. Using 25 ICME- and 35 CIR-driven storms, we have determined the ring curre…
First MMS Observation of Energetic Particles Trapped in High-Latitude Magnetic Field Depressions
Fuselier, Stephen A.; Nykyri, Katariina; Ma, Xuanye +2 more
We present a case study of the Magnetospheric Multiscale (MMS) observations of the Southern Hemispheric dayside magnetospheric boundaries under southward interplanetary magnetic field direction with strong By component. During this event MMS encountered several magnetic field depressions characterized by enhanced plasma beta and high fl…
Exospheric Neutral Hydrogen Density at the Nominal 10 RE Subsolar Point Deduced From XMM-Newton X-Ray Observations
Connor, Hyunju K.; Carter, Jennifer A.
We investigate the exospheric neutral density near the subsolar magnetopause, assuming Xgse = 10 RE as its typical location, to support the upcoming Solar wind-Magnetosphere-Ionosphere Link Explorer that will visualize the Earth's magnetosheath and cusps in soft X-rays. Neutral hydrogen density is a key parameter that controls soft X-ra…
The First Direct Observational Confirmation of Kinematic Collisionless Relaxation in Very Low Mach Number Shocks Near the Earth
Balikhin, M. A.; Gedalin, M.; Pope, S. A.
Collisionless shocks are ubiquitous throughout the known universe. They mainly convert the energy of the directed ion flow into heating. Upon crossing the shock front, the ion distribution becomes nongyrotropic. Relaxation to gyrotropy then occurs mainly via kinematic collisionless gyrophase mixing and interaction with waves. The theory of collisi…