Search Publications
VLF Transmitter Signals Observed by the Cluster Spacecraft Over a Wide Range of Latitudes
Santolík, O.; Němec, F.; Albert, J. M.
Very low frequency transmitter signals can penetrate through the ionosphere and propagate in the inner magnetosphere, being observed by spacecraft instruments with sufficient frequency resolution and range. We use 23 years of measurements performed by the Waves of High frequency and Sounder for Probing of Electron density by Relaxation instrument …
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 …
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,…
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…
Reconnection Inside a Dipolarization Front of a Diverging Earthward Fast Flow
Escoubet, C. P.; Fazakerley, A. N.; Le Contel, O. +18 more
We examine a Dipolarization Front (DF) event with an embedded electron diffusion region (EDR), observed by the Magnetospheric Multiscale (MMS) spacecraft on 08 September 2018 at 14:51:30 UT in the Earth's magnetotail by applying multi-scale multipoint analysis methods. In order to study the large-scale context of this DF, we use conjunction observ…
Global Environmental Constraints on Magnetic Reconnection at the Magnetopause From In Situ Measurements
Lavraud, B.; Génot, V.; Jeandet, A. +5 more
Progress in locating the X-line on the magnetopause beyond the atypical due south interplanetary magnetic field (IMF) condition is hampered by the fact that the global plasma and field spatial distributions constraining where reconnection could develop on the magnetopause are poorly known. This work presents global maps of the magnetic shear, curr…
The April 2023 SYM-H = −233 nT Geomagnetic Storm: A Classical Event
Henri, Pierre; Hajra, Rajkumar; Horne, Richard B. +8 more
The 23-24 April 2023 double-peak (SYM-H intensities of −179 and −233 nT) intense geomagnetic storm was caused by interplanetary magnetic field southward component Bs associated with an interplanetary fast-forward shock-preceded sheath (Bs of 25 nT), followed by a magnetic cloud (MC) (Bs of 33 nT), respectively. The…
On the Contribution of Latitude-Dependent ULF Waves to the Radial Transport of Off-Equatorial Relativistic Electrons in the Radiation Belts
Angelopoulos, Vassilis; Li, Xinlin; Ergun, Robert E. +15 more
Ultra-low frequency (ULF) waves radially diffuse hundreds-keV to few-MeV electrons in the magnetosphere, as the range of drift frequencies of such electrons overlaps with the wave frequencies, leading to resonant interactions. Theoretically this process is described by analytic expressions of the resonant interactions between electrons and ULF wav…
Magnetic Field in the Earth's Magnetosheath: Models Versus Observations
Vandas, M.; Romashets, E.
Magnetic field measurements in the Earth's magnetosheath are compared with four analytical models, namely Kobel and Flückiger (1994), (https://doi.org/10.1029/94ja01778), Romashets and Vandas (2019), (https://doi.org/10.1029/2018ja026006), Vandas and…