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arXiv2013

A note on the structure and kinematics of Harris current sheets

The flat Harris current sheet model has become a powerful initial equilibrium in theory and simulation of magnetic reconnection in the magnetotail, at the magnetopause and also in multiple current sheet models of the heliosheath and astrophysics, where it is believed that such structures may become responsible for generation of turbulence and also high energy particles. Here we investigate the philosophy behind the Harris sheet in view of the physical conditions. The kinematic treatment in this note takes care of the different dynamics of ions and electrons.

physics.space-ph↗
arXiv2013

QM theory of the thermal electron gyroradius

The average (thermal) gyroradius of charged particles is re-examined from a quantum-mechanical point of view. The straight quantum-mechanical calculation clearly reproduces its conventionally used random-mean-square (rms) expectation value. The quasi-classical approach reproduces its mean expectation value as well thus confirming the purely classical calculation. It shows that the fluctuations in the gyroradius amount to 21.5% of its rms value. This fluctuation is, however, within the usual $\sqrt{2}$-"freedom" range of choice in the definition of the rms gyroradius respectively the mean thermal speed on which the rms value is based, its correct (nonrelativistic) value $v_t^2= 2T_\perp/m_e$ and its simplified version $v_t^2=T_\perp/m_e$.

physics.plasm-ph↗
arXiv2013

An Overview of the Pathway Idea in Statistical and Physical Sciences

Pathway idea is a switching mechanism by which one can go from one functional form to another, and to yet another. It is shown that through a parameter $α$, called the pathway parameter, one can connect generalized type-1 beta family of densities, generalized type-2 beta family of densities, and generalized gamma family of densities, in the scalar as well as the matrix cases, also in the real and complex domains. It is shown that when the model is applied to physical situations then the current hot topics of Tsallis statistics and superstatistics in statistical mechanics become special cases of the pathway model, and the model is capable of capturing many stable situations as well as the unstable or chaotic neighborhoods of the stable situations and transitional stages. The pathway model is shown to be connected to generalized information measures or entropies, power law, likelihood ratio criterion or $λ-$criterion in multivariate statistical analysis, generalized Dirichlet densities, fractional calculus, Mittag-Leffler stochastic process, Krätzel integral in applied analysis, and many other topics in different disciplines. The pathway model enables one to extend the current results on quadratic and bilinear forms, when the samples come from Gaussian populations, to wider classes of populations.

math-ph↗
arXiv2013

Implementing an analytical formula for calculating M(3000)F2 in the ionosonde operated in Havana

Determining the factor M(3000)F2 is very important for ionograms analysis obtained of Ionosonde. M(3000)F2 is the result of the maximum usable frequency (MUF), for to 3000 km distance, divided by the critical frequency of the F2 layer (FoF2). Nowadays, the graphic method to determine the M(3000)F2 is used in Havana station in the ionograms analysis. The purpose of this work is to implement an analytic method that allows us the direct obtaining of M(3000)F2, so it could be programmed and incorporated as part of ionograms elaboration process in Havana station. When is used a PC, some points in the ionogram can be determined. This dataset (f; h') are used to calculate analytically the factor M(3000)F2 . Comparison between the analytic method implemented and the old graphic method are shown. The new method is more accurate and the errors are diminished in the factor M(3000)F2.

physics.space-ph↗
arXiv2013

Simulation of the dynamics in the magnetotail current sheet

The dynamics in the magnetosphere current sheet was simulated following transformations to the rectangular NxM array of cells (cellular automaton) originally proposed by Koselov and Koselova (2002). The magnetosphere part of the modeling system was organized as a rectangular arrangement of cells with a stored energy, a local redistribution of the energy will exist when a value threshold is exceeded in one of the cells. We assume that the threshold value in each cell depends on external control parameter which influences the long boundaries of the rectangular array (40x80). The model dynamics controlled by the z-component of the interplanetary magnetic field (Bz) as well as analogies between the model transient processes and the observed substorm auroral activations are discussed. The Bz correspond to temporary windows of the solar wind for a group of magnetic clouds and plasmoids. The model simulates organized patterns in the energy distribution. The function of distribution of probability (or PDF) of the size of the avalanches have a power-law form, showing evidences of a system with Self-Organized Criticality (SOC). The occurrence of big avalanches in the model is related with the activation of some intense magnetic substorm. The arrival to the terrestrial magnetopause of a solar wind with Bz negative is a fundamental condition of occurrence of magnetic substorms. While more negative it is the Bz IMF component bigger it is the value of the AE index and trigger a strong magnetic substorm.

physics.space-ph↗
arXiv2013

The Unfolding of the Spectra of Low Energy Galactic Cosmic Ray H and He Nuclei as the Voyager 1 Spacecraft Exits the Region of Heliospheric Modulation

This paper describes the unfolding of the solar modulated galactic cosmic ray H and He nuclei spectra beyond ~105 AU in the heliosheath. Between 2008.0 and 2012.3 when Voyager 1 went from about 105 to 120.5 AU the spectral intensities of these two components between about 30 and 500 MeV/nuc unfolded (increased) in a manner consistent with an average modulation potential decrease ~5 MV per AU as described by a Parker like cosmic ray transport in the heliosphere where the overall modulation is described by a modulation potential in MV. Between 120.5 and 121.7 AU, however, as a result of two sudden intensity increases starting on May 8th and August 25th, 2012, this modulation potential decreased by ~80 MV and spectra resembling possible local interstellar spectra for H and He were revealed. Considering these spectra to be the local interstellar spectra would imply that almost 1/3 of the total modulation potential of about 270 MV required to explain the spectra of these components observed at the Earth must occur in just a 1 AU radial interval in the outer heliosheath. As a result about ~80% of the total modulation potential observed at the Earth at this time occurs in the heliosheath itself. The remaining 20% of the total modulation occurs inside the heliospheric termination shock. The details of these intensity changes and their description by a simple modulation model are discussed.

physics.space-ph↗
arXiv2013

Ionospheric effects during first 2 hours after the Chelyabinsk meteorite impact

This paper presents the analysis of ionospheric effects in the region close to the Chelyabinsk meteorite explosion at 03:20UT 2013 February 15 from the Institute of Solar-Terrestrial Physics of Siberian Branch of Russian Academy of Sciences (ISTP SB RAS) EKB radar data, and from the Institute of Geophysics of Ural Branch of Russian Academy of Sciences (IG UB RAS) PARUS ionosonde data. Both instruments are located within the IG UB RAS Arti Observatory approximately 200 km northward from the estimated explosion site. According to the data obtained, the ionospheric disturbance caused by the meteorite flyby, explosion, and impact had high dynamics and amplitude. However, it obviously did not lead to a variation in the ionosphere mean parameters in the region above the disturbance center during the first 2 hours. Essential effects, however, were observed at more than 100-200 km from the explosion site and farther up to 1500 km.

physics.geo-ph↗
arXiv2013

A Comparison of the Galactic Cosmic Ray H, He and C/O Nuclei Spectra Measured Between ~5 and 500 MeV/nuc Beyond 122 AU at Voyager 1 with the Predictions of a Diffusion Model for Propagation in the Galaxy

After the disappearance of lower energy heliospheric particles at Voyager 1 starting on August 25th, 2012, spectra of H, He and C/O nuclei were revealed that resembled those to be expected for galactic cosmic rays. These spectra had intensity peaks in the range of 30-60 MeV, decreasing at both lower energies down to a few MeV and at higher energies up to several hundred MeV. We have modeled the propagation of these particles in the galaxy using an updated Leaky Box Diffusion model which determines the spectra of these components from ~2 MeV to >200 GeV. The key parameters used in the model are a galactic input spectrum ~P^-2.24, the same for all components and independent of rigidity, and a diffusion coefficient that is ~P^0.5 above a lower rigidity and increases ~beta^-1.0 below a lower rigidity ~0.56 GV. These same parameters also fit the high energy H and He data from ~10-200 GeV/nuc from the PAMELA and BESS experiments. The new Voyager spectra for all three nuclei are thus consistent with rigidity spectra ~P^-2.24 from the lowest energies to at least 100 GeV. Deviations from this spectrum can reasonably be attributed to propagation effects. Some deviations between the calculated and newly observed spectra are noted, however, below ~30 MeV/nuc, particularly for C/O nuclei, that could be significant regarding the propagation and sources of these particles.

physics.space-ph↗
arXiv2013

Calculations of the Propagated LIS Electron Spectrum Which Describe the Cosmic Ray Electron Spectrum below ~100 MeV Measured Beyond 122 AU at Voyager 1 and its Relationship to the PAMELA Electron Spectrum above 200 MeV

The new Voyager measurements of cosmic ray electrons between 6-60 MeV beyond 122 AU are very sensitive indicators of cosmic ray propagation and acceleration in the galaxy at a very low modulation level. Using a Monte Carlo diffusion model with a source spectrum with a single spectral index of -2.2 at all energies we are able to fit this observed Voyager spectrum and the contemporary PAMELA electron spectrum over an energy range from 6 MeV to ~200 GeV. This spectrum has a break in it but this break is due to propagation effects, not changes in the primary spectrum. This break is gradual, starting at > 2 GeV where the spectrum is ~E^-3.2 and continuing down to ~100 MeV or below where the spectrum becomes ~E^-1.5. At the higher energies the loss terms due to synchrotron radiation and inverse Compton effects which are ~E^2.0 steepen the exponent of the source spectrum by 1.0. At lower energies, these terms become unimportant and the loss is governed by diffusion and escape from the galaxy. A diffusion term which is proportional to beta^-1 below ~0.32 GV (which also fit the H and He spectra measured at Voyager) and has a value = 3x1028 cm^2 x s^-1 at 1 GV and a boundary at +/-1 Kpc will fit the Voyager or other similar spectra at low energies.

physics.space-ph↗
arXiv2013

Simultaneous Analysis of Recurrent Jovian Electron Increases and Galactic Cosmic Ray Decreases

The transport environment for particles in the heliosphere, e.g. galactic cosmic rays (GCRs) and MeV electrons (including those originating from Jupiters magnetosphere), is defined by the solar wind flow and the structure of the embedded heliospheric magnetic field. Solar wind structures, such as co-rotating interaction regions (CIR), can result in periodically modulation of both particles species. A detailed analysis of this recurrent Jovian electron events and galactic cosmic ray decreases measured by SOHO EPHIN is presented here, showing clearly a change of phase between both phenomena during the cause of the years 2007 and 2008. This effect can be explained by the change of difference in heliolongitude between the Earth and Jupiter, which is of central importance for the propagation of Jovian electrons. Furthermore, the data can be ordered such that the 27-day Jovian electron variation vanishes in the sector which does not connect the Earth with Jupiter magnetically using observed solar wind speeds.

astro-ph.HE↗
arXiv2013

Mode-locked Lasers Applied to Deflecting a Near Earth Object on Collision Course with Earth

We consider synchronized trains of sub-picosecond pulses generated by mode-locked lasers applied to deflection of near Earth objects (NEO) on collision course with Earth. Our method is designed to avoid a predicted collision of the NEO with Earth by at least the diameter of Earth. We estimate deflecting a 10,000 MT NEO, such as the asteroid which struck Earth near Chelyabinsk, Russia to be feasible within several months using average power in the ten kilowatt range. We see this deflection method as scalable to larger NEO to a degree not possible using continuous laser systems.

physics.space-ph↗
arXiv2013

Establishment of the new Ecuadorian solar physics phenomena division

Crucial physical phenomena occur in the equatorial atmosphere and ionosphere, which are currently understudied and poorly understood. Then, scientific campaigns for monitoring equatorial region are required, which will provide the data for analyzing and creating adequate models. Ecuador is located in strategic geographical position where these studies can be performed, providing data for the scientific community working for understanding the nature of these physical systems. The Quito Astronomical Observatory of National Polytechnic School is working in this direction, promoting research in Space Sciences for studying the equatorial zone. With the participation and valuable collaboration of international initiatives like AWESOME, MAGDAS, SAVNET and CALLISTO, the Quito Observatory is creating a new space physics division on the basis of the International Space Weather Initiative. In this contribution, the aforementioned initiative is presented inviting leaders from others scientific projects to deploy their instruments and to join us giving the necessary support for the creation of this new strategic research center.

astro-ph.IM↗
arXiv2013

First Magdas Equipment In Ecuador

The Magnetic Data Acquisition System (MAGDAS) was installed in the protected Jerusalem Park in Malchingui-Ecuador in October of 2012, under the joint collaboration between Kyushu University of Japan and the Quito Astronomical Observatory of the National Polytechnic School of Ecuador. In this paper, we describe the installation process and present the preliminary data obtained with the MAGDAS equipment. The behavior of the four components, D, H, Z and F allow us to see the importance of having the Ecuador station where the magnetic field has not been systematically measured before, in valuable contribution to study of the equatorial atmosphere.

physics.space-ph↗
arXiv2013

Fast magnetosonic modes of cylindrical magnetotail

FMS modes are studied in the model of the magnetotail as a cylinder with plasma sheet. The presence of the plasma sheet leads to a significant modification of the modes existing in the magnetotail in the form of a cylinder with no plasma sheet. Azimuthal scales of the FMS modes differ significantly between the lobes and the plasma sheet. The azimuthal scale in the plasma sheet is much smaller than that in the magnetotail lobes. FMS waves with certain parameters are strongly reflected from the boundary between the lobes and the plasma sheet and are very weak in the plasma sheet.

physics.space-ph↗
arXiv2013

Time-dependent cosmic ray modulation in the outer heliosphere: Signatures of a heliospheric asymmetry and model predictions along Voyager 1 and 2 trajectories

A two-dimensional, time-dependent numerical model is used to calculate the modulation of cosmic rays in the heliosphere. Computations are compared to spacecraft observations in the inner and outer heliosphere. It is shown that the model produces cosmic ray proton intensities compatible to different spacecraft observations on a global scale, at Earth and along both Voyager spacecraft trajectories. The study reveals that when the same modulation parameters, which resulted in compatible intensities along Voyager 1, were assumed along the Voyager 2 trajectory, the model failed to reproduce the observations. The study also found that any change in diffusion parameters alone could not reproduce the cosmic ray observations along Voyager 2 so that changes to the heliospheric geometry were necessary i.e the computed intensities along both Voyager trajectories suggest that the heliosphere is asymmetric. Furthermore, $E >$ 70 MeV and 133-242 MeV proton intensities along Voyager 1 and 2 trajectories are predicted from end of 2012 onwards. It is shown that the computed intensities along Voyager 1 increase with an almost constant rate up to the heliopause. However, the model shows that Voyager 2 is still under the influence of temporal solar activity changes because of its relatively large distance to the heliopause. Along the Voyager 2 trajectory, the intensities remained generally constant for some time and should soon start to increase steadily.

astro-ph.HE↗
arXiv2013

Hypermodular Distributed Solar Power Satellites -- Exploring a Technology Option for Near-Term LEO Demonstration and GLPO Full-Scale Plants

This paper presents a new and innovative design for scaleable space solar power systems based on satellite self-assembly and microwave spatial power combination. Lower system cost of utility-scale space solar power is achieved by independence of yet-to-be-built in-space assembly and transportation infrastructure. Using current and expected near-term technology, this study explores a design for near-term space solar power low-Earth orbit demonstrators and for mid-term utility-scale power plants in geosynchronous Laplace plane orbits. High-level economic considerations in the context of current and expected future launch costs are given as well.

physics.space-ph↗
arXiv2013

Fluctuations in the interplanetary electric potential and energy coupling between the solar-wind and the magnetosphere

We utilize solar rotation average geomagnetic index ap and various solar wind plasma and field parameters for four solar cycles 20-23. We perform analysis to search for a best possible coupling function at 27-day time resolution. Regression analysis using these data at different phases of solar activity (increasing including maximum/decreasing including minimum) led us to suggest that the time variation of interplanetary electric potential is a better coupling function for solar wind-magnetosphere coupling. We suspect that a faster rate of change in interplanetary electric potential at the magnetopause might enhance the reconnection rate and energy transfer from the solar wind into the magnetosphere. The possible mechanism that involves the interplanetary potential fluctuations in influencing the solar wind-magnetosphere coupling is being investigated.

astro-ph.SR↗