Search Publications
A statistical study on the shape and position of the magnetotail neutral sheet
Zhang, Tielong; Nakamura, Rumi; Ge, Yasong +3 more
We study the average shape and position of the magnetotail neutral sheet based on magnetic field data obtained by Cluster, Geotail, TC-1, and THEMIS from the years 1995 to 2013. All data in the aberrated GSM (geocentric solar magnetospheric) coordinate system are normalized to the same solar wind pressure 2 nPa and downtail distance X ∼ -20RE…
Spatial dimensions of the electron diffusion region in anti-parallel magnetic reconnection
Nakamura, Rumi; Nakamura, Takuma; Haseagwa, Hiroshi
Spatial dimensions of the detailed structures of the electron diffusion region in anti-parallel magnetic reconnection were analyzed based on two-dimensional fully kinetic particle-in-cell simulations. The electron diffusion region in this study is defined as the region where the positive reconnection electric field is sustained by the electron ine…
Ion Bernstein waves in the magnetic reconnection region
Glassmeier, K. -H.; Nakamura, R.; Baumjohann, W. +3 more
Four-dimensional energy spectra and a diagram for dispersion relations are determined for the first time in a magnetic reconnection region in the magnetotail using data from four-spacecraft measurements by the Cluster mission on a spatial scale of 200 km, about 0.1 ion inertial lengths. The energy spectra are anisotropic with an extension in the p…
Proton and heavy ion acceleration by stochastic fluctuations in the Earth's magnetotail
Zimbardo, Gaetano; Greco, Antonella; Artemyev, Anton V. +2 more
Spacecraft observations show that energetic ions are found in the Earth's magnetotail, with energies ranging from tens of keV to a few hundreds of keV. In this paper we carry out test particle simulations in which protons and other ion species are injected in the Vlasov magnetic field configurations obtained by Catapano et al. (2015). These config…
Observations of diffusion in the electron halo and strahl
Goldstein, Melvyn L.; Gurgiolo, Chris
Observations of the three-dimensional solar wind electron velocity distribution functions (VDF) using ϕ-θ plots often show a tongue of electrons that begins at the strahl and stretches toward a new population of electrons, termed the proto-halo, that exists near the projection of the magnetic field opposite that associated with the strahl. The ene…
Energetic ions scattered into the loss cone with observations of the Cluster satellite
Yuan, Zhigang; Xiong, Ying; Wang, Jingfang
In this paper, we report in situ observations by the Cluster spacecraft of energetic ions scattered into the loss cone during the inbound pass from the plasma sheet into the plasmasphere. During the inbound pass of the plasma sheet, Cluster observed the isotropy ratio of energetic ions to gradually decrease from unity and the isotropic boundary ex…
Current sheet flapping in the near-Earth magnetotail: peculiarities of propagation and parallel currents
Nakamura, Rumi; Petrukovich, Anatoly A.; Artemyev, Anton V. +1 more
We consider series of tilted current sheet crossings, corresponding to flapping waves in the near-Earth magnetotail. We analyse Cluster observations from 2005 to 2009, when spacecraft visited the magnetotail neutral plane near X ∈ [ - 17, - 8], Y ∈ [ - 16, - 2] RE (in the GSM system). Large separation of spacecraft allows us …
Wave-particle resonance condition test for ion-kinetic waves in the solar wind
Glassmeier, K. -H.; Marsch, E.; Narita, Y. +3 more
Conditions for the Landau and cyclotron resonances are tested for 543 waves (identified as local peaks in the energy spectra) in the magnetic field fluctuations of the solar wind measured by the Cluster spacecraft on a tetrahedral scale of 100 km. The resonance parameters are evaluated using the frequencies in the plasma rest frame, the parallel c…
Inverse scattering problem in turbulent magnetic fluctuations
Narita, Yasuhito; Baumjohann, Wolfgang; Treumann, Rudolf A.
We apply a particular form of the inverse scattering theory to turbulent magnetic fluctuations in a plasma. In the present note we develop the theory, formulate the magnetic fluctuation problem in terms of its electrodynamic turbulent response function, and reduce it to the solution of a special form of the famous Gelfand-Levitan-Marchenko equatio…
Critical pitch angle for electron acceleration in a collisionless shock layer
Narita, Y.; Motschmann, U.; Comişel, H.
Collisionless shock waves in space and astrophysical plasmas can accelerate electrons along the shock layer by an electrostatic potential, and scatter or reflect electrons back to the upstream region by the amplified magnetic field or turbulent fluctuations. The notion of the critical pitch angle is introduced for non-adiabatic electron accelerati…