Related papers: Threshold of auroral intensification reduced by el…
High resolution optical measurements have revealed that a sudden brightening of aurora and its deformation from an arc-like to a vortex street structure appear just at the onset of substorm. The instability of Alfv$\acute{\rm e}$n waves…
In the Earth auroral zone, the electron acceleration by Alfv\'en waves is sometimes a precursor of the non-propagating acceleration structures. In order to investigate how Alfv\'en waves could generate non-propagating electric fields, a…
The overshooting convective motions in the solar photosphere are frequently proposed as the source for the excitation of Alfv\'en waves. However, the photosphere is a) very weakly ionized, and, b) the dynamics of the plasma particles in…
Recent observations have demonstrated that very-low mass stars and brown dwarfs are capable of sustaining strong magnetic fields despite their cool and neutral atmospheres. These kG field strengths are inferred based on strong highly…
Near-equatorial great enhancements of the quasi-trapped >30 keV electrons at low-altitudes are studied during strong geomagnetic storms. We have found that the transient phenomenon often began at the morning and was capable to live several…
The acceleration of electrons at 1-10 keV energies is the cause of the polar aurora displays, and an important factor of magnetic energy transfer from the solar wind to the Earth. Two main families of acceleration processes are observed:…
Collisionless shock waves, found in supernova remnants, interstellar, stellar, and planetary environments, and laboratories, are one of nature's most powerful particle accelerators. This study combines in situ satellite measurements with…
Ion-neutral collisions may lead to the damping of Alfven waves in chromospheric and prominence plasmas. Neutral helium atoms enhance the damping in certain temperature interval, where the ratio of neutral helium and neutral hydrogen atoms…
We extend and reconcile recent work on turbulence and particle heating in advection-dominated accretion flows. For approximately equipartition magnetic fields, the turbulence primarily heats the electrons. For weaker magnetic fields, the…
It is shown that low-collisionality plasmas cannot support linearly polarized shear-Alfv\'en fluctuations above a critical amplitude $\delta B_{\perp}/B_{0} \sim \beta^{\,-1/2}$, where $\beta$ is the ratio of thermal to magnetic pressure.…
We use 2.5-D electromagnetic particle-in-cell simulation code to investigate the acceleration of electrons in solar coronal holes through the interaction of Alfv\'en waves with an interplume region. The interplume is modeled by a cavity…
We present a simple (stationary) mechanism capable of generating the auroral downward field-aligned electric field {that is} needed for {accelerating the ionospheric electron component up into the magnetosphere and confining the ionospheric…
The aim of the Swedish-Japanese EISCAT campaign in February 1999 was to measure the ionospheric parameters inside and outside the auroral arcs. The ion line radar experiment was optimised to probe the E-region and lower F-region with as…
A high energy density plasma embedded in a neutral gas is able to launch an outward-propagating nonlinear electrostatic ionization wave that traps energetic electrons. The trapping maintains a strong sheath electric field, enabling rapid…
The collisional drift wave instability is reexamined taking into account the ion response in the direction parallel to the magnetic field lines, which appears due to friction with electrons and which can not be omitted in view of the…
The new generation of lithography tools use high energy EUV radiation which ionizes the present background gas due to photoionization. To predict and understand the long term impact on the highly delicate mirrors It is essential to…
The present investigation is directed at exploring southern polar ionospheric responses to intense space weather events and their correlations with plasma convection and auroral precipitation. The main phases of six geomagnetic storms…
It is shown that in low-beta, weakly collisional plasmas, such as the solar corona, some instances of the solar wind, the aurora, inner regions of accretion discs, their coronae, and some laboratory plasmas, Alfv\'enic fluctuations produce…
The solar ultraviolet intensities of spectral lines originating from Li- and Na-like ions have been observed to surpass the expectations derived from plasmas with coronal approximation. The violation of the coronal approximation can be…
Turbulence in highly magnetized plasma can be relativistic and induce an electric field comparable to the background magnetic field. Such a strong electric field can affect the emission process of non-thermal electrons. As the first step…