649 research outputs found
The coupling between the solar wind and proton fluxes at GEO
The relationship between the solar wind and the proton flux at geosynchronous Earth orbit (GEO) is investigated using the error reduction ratio (ERR) analysis. The ERR analysis is able to search for the most appropriate inputs that control the evolution of the system. This approach is a black box method and is able to derive a mathematical model of a system from input-output data. This method is used to analyse eight energy ranges of the proton flux at GEO from 80 keV to 14.5 MeV. The inputs to the algorithm were solar wind velocity, density and pressure; the Dst index; the solar energetic proton (SEP) flux; and a function of the interplanetary magnetic field (IMF) tangential magnitude and clock angle. The results show that for lowest five energy channels (80 to 800 keV) the GEO proton fluxes are controlled by the solar wind velocity with a lag of two to three days. However, above 350 keV, the SEP fluxes, accounts for a significant portion of the GEO proton flux variance. For the highest three energy channels (0.74 to 14.5 MeV), the SEPs account for the majority of the ERR. The results also show an anisotropy of protons with gyrocenters inside GEO and outside GEO, where the protons inside GEO are controlled partly by the Dst index and also an IMF-clock angle function. © 2013 Author(s)
Determination of wave vectors using the phase differencing method
Due to the collisionless nature of space plasmas, plasma waves play an
important role in the redistribution of energy between the various particle
populations in many regions of geospace. In order to fully comprehend such
mechanisms it is necessary to characterise the nature of the waves present.
This involves the determination of properties such as wave vector <b><i>k</b></i>.
There are a number of methods used to calculate <b><i>k</b></i> based on the
multipoint measurements that are now available. These methods rely on the
fact that the same wave packet is simultaneously observed at two or more
locations whose separation is small in comparison to the correlation length
of the wave packet. This limitation restricts the analysis to low frequency
(MHD) waves. In this paper we propose an extension to the phase differencing
method to enable the correlation of measurements that were not made
simultaneously but differ temporally by a number of wave periods. The method
is illustrated using measurements of magnetosonic waves from the Cluster
STAFF search coil magnetometer. It is shown that it is possible to identify
wave packets whose coherence length is much less than the separation between
the measurement locations. The resulting dispersion is found to agree with
theoretical results
Electromagnetohydrodynamics
Interaction of plasma flow with a magnetic obstacle is a frequent process in
many laser-plasma experiments in the laboratory, and is an important event in
many astrophysical objects such as X-ray pulsars, AGN, GRB etc. As a result of
plasma penetration through the magnetic wall we could expect a formation of
magnetohydrodynamic (MHD) shock waves, as well as of electromagnetic (EM) ones.
To study these processes we need equations following from hydrodynamic and
Maxwell equations, which in the limiting situations describe MHD and EM waves,
and are valid for the general case, when both phenomena are present. Here we
derive a set of equations following from hydrodynamic and Maxwell equations,
without neglecting a displacement current, needed for a formation of EM waves.
We find a dispersion equation describing a propagation of a weak linear wave in
a magnetized plasma along the axis, perpendicular to the magnetic field
, which contains MHD, hydrodynamic and EM waves in the limiting cases,
and some new types of behaviour in a general situation. We consider a plasma
with zero viscosity and heat conductivity, but with a finite electric
conductivity with a scalar coefficient.Comment: 8 papers, 8 figures, 1 table, to be submitted in PR
Investigation of the Chirikov resonance overlap criteria for equatorial magnetosonic waves
Observations of equatorial magnetosonic waves made during the Cluster I nnerMagnetospheric Campaign clearly show discrete spectra consisting of emissions around harmonics of theproton gyrofrequency. Equatorial magnetosonic waves are important because of their ability to efficientlyscatter electrons in energy and pitch angle. This wave-particle interaction is numerically modeled throughthe use of diffusion coefficients, calculated based on a continuous spectrum such as that observed byspectrum analyzers. Using the Chirikov overlap resonance criterion, the calculation of the diffusioncoefficient will be assessed to determine whether they should be calculated based on the discrete spectralfeatures as opposed to a continuous spectrum. For the period studied, it is determined that the discretenature of the waves does fulfill the Chirikov overlap criterion and so the use of quasi-linear theory with theassumption of a continuous frequency spectrum is valid for the calculation of diffusion coefficients
A supersymmetric model for triggering Supernova Ia in isolated white dwarfs
We propose a model for supernovae Ia explosions based on a phase transition
to a supersymmetric state which becomes the active trigger for the deflagration
starting the explosion in an isolated sub-Chandrasekhar white dwarf star. With
two free parameters we fit the rate and several properties of type Ia
supernovae and address the gap in the supermassive black hole mass
distribution. One parameter is a critical density fit to about
g/cc while the other has the units of a space time volume and is found to be of
order Gyr where is the earth radius. The model involves
a phase transition to an exact supersymmetry in a small core of a dense star.Comment: 20 pages, 5 figures, expanded version to be published in Physical
Review
Regional impact of Ozone precursor emissions on NO<sub>x</sub> and O<sub>3</sub> levels at ZOTTO tall tower in Central Siberia
Contemporary foreign language teachers training
The article deals with contemporary foreign language teacher’s training. Based on experience it is analyzed foreign language teacher’s training system in Russia and noted specific tendencies in teacher’s training and his/her personal qualities. The authors consider innovative approaches directed to contemporary teacher of the 21-st century who is a central facilitator of a foreign language educational process. Due to the research there were established the most effective learning techniques for development of teacher’s methodological thinking and his/her personal qualities formation (communication skills, empathy, creativity, reflexivity etc.
Formation of official loyalty of cadets in educational process of higher educational institutions of Russian penitentiary system
© Author(s).This article is aimed at revealing the foundations of the formation of the official loyalty among the cadets of higher education institutions of the FPS of Russia by the institutions staff, and first of all, by the faculty. Leading methods of research of this problem in this article were: the analysis of scientific papers and official documents, questionnaires, interviews, observation. The article describes the key problems of formation of the official loyalty among FPS of Russia employees. Article identifies factors both assisting and impeding the process of the purposeful formation of official loyalty. Also the attention is focused on the heterogeneity of mechanisms of formation of official loyalty in behavior on the level of compliance with legal and ethical norms, disclosed the peculiarities of formation of official loyalty in the context of the educational process in educational institutions of the FPS of Russia. Principles and steps of purposeful formation of official loyalty in the higher education institutions of the FPS of Russia, practical recommendations in this direction are recommended
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