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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,…
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 global mapping of electron precipitation and ionospheric conductance from whistler-mode chorus waves
Gillespie, Dillon; Connor, Hyunju Kim; Ma, Qianli +4 more
Auroral precipitation is the second major energy source after solar irradiation that ionizes the Earth's upper atmosphere. Diffuse electron aurora caused by wave-particle interaction in the inner magnetosphere (L < 8) takes over 60% of total auroral energy flux, strongly contributing to the ionospheric conductance and thus to the ionosphere-the…
Global Three-Dimensional Draping of Magnetic Field Lines in Earth's Magnetosheath From In-Situ Spacecraft Measurements
Lavraud, B.; Génot, V.; Jeandet, A. +4 more
Magnetic field draping occurs when the magnetic field lines frozen in a plasma flow wrap around a body or plasma environment. The draping of the interplanetary magnetic field (IMF) around the Earth's magnetosphere has been confirmed in the early days of space exploration. However, its global and three-dimensional structure is known from modeling o…
Massive Multi-Mission Statistical Study and Analytical Modeling of the Earth's Magnetopause: 1. A Gradient Boosting Based Automatic Detection of Near-Earth Regions
Lavraud, B.; Jeandet, A.; Aunai, N. +3 more
We present an automatic classification method of the three near-Earth regions, the magnetosphere, the magnetosheath and the solar wind from their in situ data measurement by multiple spacecraft. Based on gradient boosting classifier, this very simple and very fast method outperforms the detection routines based on manually set thresholds. The meth…
Massive Multi-Mission Statistical Study and Analytical Modeling of the Earth's Magnetopause: 2. Shape and Location
Lavraud, B.; Jeandet, A.; Aunai, N. +3 more
The Earth magnetopause is the boundary between the magnetosphere and the shocked solar wind. Its location and shape are primarily determined by the properties of the solar wind and interplanetary magnetic field (IMF) but the nature of the control parameters and to what extent they impact the stand-off distance, the flaring, and the symmetries, on …
Massive Multi-Mission Statistical Study and Analytical Modeling of the Earth's Magnetopause: 3. An Asymmetric Non Indented Magnetopause Analytical Model
Lavraud, B.; Jeandet, A.; Aunai, N. +3 more
In a companion statistical study, we showed that the expression of the magnetopause surface as a power law of an elliptic function of the zenith angle θ holds at lunar distances, that the flaring of the magnetopause surface is influenced by the Interplanetary Magnetic Field (IMF) By component and that the IMF Bx component had…
FARWEST: Efficient Computation of Wave-Particle Interactions for a Dynamic Description of the Electron Radiation Belt Diffusion
Darrouzet, Fabien; Santolik, Ondrej; Pierrard, Viviane +5 more
In this paper, we present a new method to compute rapidly, wave particle interaction induced pitch angle and momentum diffusion coefficients. Those terms are normally obtained by the numerical solving of equations based on the quasi-linear theory. However, this bulk resolution leads to a high computational cost, preventing the integration of plasm…
Massive Multi-Mission Statistical Study and Analytical Modeling of the Earth's Magnetopause: 4. On the Near-Cusp Magnetopause Indentation
Lavraud, B.; Jeandet, A.; Aunai, N. +3 more
The shape and location of the magnetopause current sheet in the near-cusp region is still a debated question. Over time, several observations led to contradictory conclusions regarding the presence of an indentation of the magnetopause in that region. As a result several empirical models consider the surface is indented in that region, while some …
Magnetosheath Filamentary Structures Driven by Foreshock Energetic Ions
Wei, Xinhua; Ma, Yuduan; Yang, Junying +1 more
Previous simulation studies have revealed the formation of magnetosheath filamentary structures by foreshock energetic ions. We report Cluster and Double Star observations of three such events triggered by a foreshock bubble, a hot flow anomaly and a traveling foreshock, respectively. In each case, in association with the onset of foreshock energe…