Search Publications
In-situ observations of flux ropes formed in association with a pair of spiral nulls in magnetotail plasmas
Dunlop, Malcolm; He, Jiansen; Xie, Lun +9 more
Signatures of secondary islands are frequently observed in the magnetic reconnection regions of magnetotail plasmas. In this paper, magnetic structures with the secondary-island signatures observed by Cluster are reassembled by a fitting-reconstruction method. The results show three-dimensionally that a secondary island event can manifest the flux…
Spontaneous emission of electromagnetic and electrostatic fluctuations in magnetized plasmas: Quasi-parallel modes
Kim, Sunjung; Yoon, Peter H.; Choe, G. S.
The present paper is devoted to the theoretical and numerical analysis of the spontaneously emitted electromagnetic fluctuations characterized by quasi-parallel wave vectors relative to the ambient magnetic field. The formulation is based upon the Klimontovich plasma kinetic theory. The comparative study is carried out between the spontaneously em…
Generalized double-gradient model of flapping oscillations: Oblique waves
Korovinskiy, D. B.; Kiehas, S. A.
The double-gradient model of flapping oscillations is generalized for oblique plane waves, propagating in the equatorial plane. It is found that longitudinal propagation (ky = 0) is prohibited, while transversal (kx = 0) or nearly transversal waves should possess a maximum frequency, diminishing with the reduction of | k…
Nonlinear effects related to circularly polarized dispersive Alfvén waves
Sharma, R. P.; Gaur, Nidhi; Sharma, Swati
In situ measurements of solar wind have strongly implicated its turbulent behavior. The observed power spectra report a breakpoint around length scales of the order of ion scales. As one of the responsible mechanisms for the observed steepening in power spectrum, our approach includes a right circularly polarized dispersive Alfvén wave (DAW) with …
Double layer electric fields aiding the production of energetic flat-top distributions and superthermal electrons within magnetic reconnection exhausts
Borg, A. L.; Egedal, J.; Daughton, W. +1 more
Using a kinetic simulation of magnetic reconnection, it was recently shown that magnetic-field-aligned electric fields (E∥) can be present over large spatial scales in reconnection exhausts. The largest values of E∥ are observed within double layers. The existence of double layers in the Earth's magnetosphere is well document…
Double-reconnected magnetic structures driven by Kelvin-Helmholtz vortices at the Earth's magnetosphere
Califano, F.; Pegoraro, F.; Faganello, M. +1 more
In an almost collisionless magnetohydrodynamic plasma in a relatively strong magnetic field, stresses can be conveyed far from the region where they are exerted, e.g., through the propagation of Alfvèn waves. The forced dynamics of line-tied magnetic structures in solar and stellar coronae (see, e.g., A. F. Rappazzo and E. N. Parker, Astrophys. J.…
Observation and numerical modeling of chromospheric evaporation during the impulsive phase of a solar flare
Watanabe, Tetsuya; Murakami, Izumi; Imada, Shinsuke
We have studied the chromospheric evaporation flow during the impulsive phase of the flare by using the Hinode/EUV Imaging Spectrometer observation and 1D hydrodynamic numerical simulation coupled to the time-dependent ionization. The observation clearly shows that the strong redshift can be observed at the base of the flaring loop only during the…
Current sheets with inhomogeneous plasma temperature: Effects of polarization electric field and 2D solutions
Artemyev, A. V.; Vasko, I. Y.; Zimbardo, G. +1 more
We develop current sheet models which allow to regulate the level of plasma temperature and density inhomogeneities across the sheet. These models generalize the classical Harris model via including two current-carrying plasma populations with different temperature and the background plasma not contributing to the current density. The parameters o…
3D magnetic field configuration of small-scale reconnection events in the solar plasma atmosphere
Shimizu, T.
The outer solar atmosphere, i.e., the corona and the chromosphere, is replete with small energy-release events, which are accompanied by transient brightening and jet-like ejections. These events are considered to be magnetic reconnection events in the solar plasma, and their dynamics have been studied using recent advanced observations from the H…
The double-gradient magnetic instability: Stabilizing effect of the guide field
Korovinskiy, D. B.; Semenov, V. S.; Erkaev, N. V. +7 more
The role of the dawn-dusk magnetic field component in stabilizing of the magnetotail flapping oscillations is investigated in the double-gradient model framework (Erkaev et al., Phys. Rev. Lett. 99, 235003 (2007)), extended for the magnetotail-like configurations with non-zero guide field By. Contribution of the guide field is examined …