The role of oxygen ions in the formation of a bifurcated current sheet in the magnetotail

Cluster observations in the near-Earth magnetotail have shown that sometimes the current sheet is bifurcated, i.e. it is divided in two layers. The influence of magnetic turbulence on ion motion in this region is investigated by numerical simulation, taking into account the presence of both protons and oxygen ions. The magnetotail current sheet is modeled as a magnetic field reversal with a normal magnetic field component $B_n$, plus a three-dimensional spectrum of magnetic fluctuations $\delta {\bf B}$, which represents the observed magnetic turbulence. The dawn-dusk electric field E$_y$ is also included. A test particle simulation is performed using different values of $\delta {\bf B}$, E$_y$ and injecting two different species of particles, O$^+$ ions and protons. O$^+$ ions can support the formation of a double current layer both in the absence and for large values of magnetic fluctuations ($\delta B/B_0 = 0.0$ and $\delta B/B_0 \geq 0.4$, where B$_0$ is the constant magnetic field in the magnetospheric lobes).Comment: 8 pages, 8 figures. J. Geophys. Res., in pres

The Structure of Martian Magnetosphere at the Dayside Terminator Region as Observed on MAVEN Spacecraft

We analyzed 44 passes of the MAVEN spacecraft through the magnetosphere, arranged by the angle between electric field vector and the projection of spacecraft position radius vector in the YZ plane in MSE coordinate system (${\theta}$ E ). All passes were divided into 3 angular sectors near 0{\deg}, 90{\deg} and 180{\deg} ${\theta}$ E angles in order to estimate the role of IMF direction in plasma and magnetic properties of dayside Martian magnetosphere. The time interval chosen was from January 17 through February 4, 2016 when MAVEN was crossing the dayside magnetosphere at SZA ~ 70{\deg}. Magnetosphere as the region with prevailing energetic planetary ions is always found between the magnetosheath and the ionosphere. 3 angular sectors of dayside interaction region in MSE coordinate system with different orientation of the solar wind electric field vector E = -1/c V x B showed that for each sector one can find specific profiles of the magnetosheath, the magnetic barrier and the magnetosphere. Plume ions originate in the northern MSE sector where motion electric field is directed from the planet. This electric field ejects magnetospheric ions leading to dilution of magnetospheric heavy ions population, and this effect is seen in some magnetospheric profiles. Magnetic barrier forms in front of the magnetosphere, and relative magnetic field magnitudes in these two domains vary. The average height of the boundary with ionosphere is ~530 km and the average height of the magnetopause is ~730 km. We discuss the implications of the observed magnetosphere structure to the planetary ions loss mechanism.Comment: 24 pages, 13 figure

Estimation of number of runaway electrons per avalanche in Earth's atmosphere

The connection between thunderstorms and relativistic runaway electron avalanches is an important topic that has attracted the attention of many researchers. Among other things, there are a lot of various simulations of the dynamics of electron avalanches. This article was written mostly in response to the article "The critical avalanche of runaway electrons" by Evgeny Oreshkin et al, which shows rather large numbers for an estimate of the number of runaway electrons, but it also contains the results of our own simulation and comparison with other papers

Plasma sheet structure in the magnetotail: kinetic simulation and comparison with satellite observations

We use the results of a three-dimensional kinetic simulation of an Harris current sheet to propose an explanation and to reproduce the ISEE-1/2, Geotail, and Cluster observations of the magnetotail current sheet structure. Current sheet flapping, current density bifurcation, and reconnection are explained as the results of the kink and tearing instabilities, which dominate the current sheet evolution.Comment: Submitted to Geophys. Res. Lett. (2003

The right of citizens to assemble peacefully, unarmed, to hold rallies and demonstrations: historical origins and genesis of formation

The subject matter of the study is the genesis and historical stages of the formation of the right of citizens to assemble peacefully, without weapons, to hold rallies, marches and demonstrations. Research results. The article, based on the analyzed materials, carried out a theoretical and legal analysis of the main elements of the conceptual and categorical apparatus of research, which is related to the essence and content of the right to peaceful assembly and its general importance in the system of legal values; the historical origins are outlined and the genesis of the formation of the constitutional right of citizens to assemble peacefully, without weapons and to hold meetings, rallies, marches and demonstrations is clarified; on the basis of generalization of scientific positions and norms of the legislation of Ukraine, and also foreign countries, including various historical periods, concerning legal regulation of the outlined question; complex theoretical and practical conclusions on the outlined problems are substantiated, which in our opinion can fragmentally influence the functioning of the relevant institution and the settlement of the main problems of its law enforcement. The practical significance of the studied question is that as a result of the outlined characteristic features of historical stages and genesis of formation of the corresponding institute the further scientific working out of problematic questions of its functioning, and also optimization of the basic problematic questions seems possible

Particle Acceleration and Magnetic Dissipation in Relativistic Current Sheet of Pair Plasmas

We study linear and nonlinear development of relativistic and ultrarelativistic current sheets of pair plasmas with antiparallel magnetic fields. Two types of two-dimensional problems are investigated by particle-in-cell simulations. First, we present the development of relativistic magnetic reconnection, whose outflow speed is an order of the light speed c. It is demonstrated that particles are strongly accelerated in and around the reconnection region, and that most of magnetic energy is converted into "nonthermal" part of plasma kinetic energy. Second, we present another two-dimensional problem of a current sheet in a cross-field plane. In this case, the relativistic drift kink instability (RDKI) occurs. Particle acceleration also takes place, but the RDKI fast dissipates the magnetic energy into plasma heat. We discuss the mechanism of particle acceleration and the theory of the RDKI in detail. It is important that properties of these two processes are similar in the relativistic regime of T > mc^2, as long as we consider the kinetics. Comparison of the two processes indicates that magnetic dissipation by the RDKI is more favorable process in the relativistic current sheet. Therefore the striped pulsar wind scenario should be reconsidered by the RDKI.Comment: To appear in ApJ vol. 670; 60 pages, 27 figures; References and typos are fixe