Latest in physics.space-ph

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Why do some probabilistic forecasts lack reliability?Apr 18 2019In this work, we investigate the reliability of the probabilistic binary forecast. We mathematically prove that a necessary, but not sufficient, condition for achieving a reliable probabilistic forecast is maximizing the Peirce skill score (PSS) at the ... More
Collisionless Energy Transfer in Kinetic Turbulence: Field-Particle Correlations in Fourier SpaceApr 18 2019Turbulence is commonly observed in nearly collisionless heliospheric plasmas, including the solar wind and corona and the Earth's magnetosphere. Understanding the collisionless mechanisms responsible for the energy transfer from the turbulent fluctuations ... More
Role of magnetic field curvature in magnetohydrodynamic turbulenceApr 17 2019Magnetic field are transported and tangled by turbulence, even as they lose identity due to nonideal or resistive effects. On balance field lines undergo stretch-twist-fold processes. The curvature field, a scalar that measures the tangling of the magnetic ... More
Scattering of Strahl Electrons in the Solar Wind between 0.3 and 1 au: Helios ObservationsApr 17 2019Electron velocity distribution functions in the solar wind according to standard models consist of 4 components, of which 3 are symmetric - the core, the halo, and the superhalo, and one is magnetic field-aligned, beam-like population, referred to as ... More
Heliospheric Evolution of Magnetic CloudsApr 17 2019Interplanetary evolution of eleven magnetic clouds (MCs) recorded by at least two radially aligned spacecraft is studied. The in situ magnetic field measurements are fitted to a cylindrically symmetric Gold-Hoyle force-free uniform-twist flux-rope configuration. ... More
Effects of Electromagnetic Acceleration on the StarOne C1 Satellite Using Planar Antenna ArrayApr 16 2019Artificial satellites perform downlink communication or transmission with earth stations. These transmissions are made from an array of antennas chosen to increase directivity and gain in the transmission of the electromagnetic signal. It occurs that ... More
Energy conversion in turbulent weakly-collisional plasmas: Eulerian Hybrid Vlasov-Maxwell simulationsApr 16 2019Kinetic simulations based on the Eulerian Hybrid Vlasov-Maxwell (HVM) formalism permit the examination of plasma turbulence with useful resolution of the proton velocity distribution function (VDF). The HVM model is employed here to study the balance ... More
Evolution of three-dimensional Relativistic Ion Weibel Instability: Competition with Kink InstabilityApr 15 2019In this paper, we report our recent findings on the relativistic Weibel instability and its nonlinear saturation by performing numerical simulations of collisionless plasmas. Analysis of the obtained numerical results revealed that the nonlinear phase ... More
Studying dawn-dusk asymmetries of Mercury's magnetotail using MHD-EPIC simulationsApr 14 2019MESSENGER has observed a lot of dawn-dusk asymmetries in Mercury's magnetotail, such as the asymmetries of the cross-tail current sheet thickness and the occurrence of flux ropes, dipolarization events and energetic electron injections. In order to obtain ... More
Observations of small-scale energetic events in the solar transition region: explosive events, UV bursts and network jetsApr 14 2019In this paper, we review observational aspects of three common small-scale energetic events in the solar transition region (TR), namely: TR explosive events, ultraviolet bursts and jets. These events are defined in either (both) spectral or (and) imaging ... More
Seasonal Water "Pump" in the Atmosphere of Mars: Vertical Transport to the ThermosphereApr 12 2019We present results of simulations with the Max Planck Institute general circulation model (MPI-MGCM) implementing a hydrological cycle scheme. The simulations reveal a seasonal water "pump" mechanism responsible for the upward transport of water vapor. ... More
Meteor shower forecasting in near-Earth spaceApr 12 2019NASA's Meteoroid Environment Office (MEO) produces an annual meteor shower forecast in order to help spacecraft operators assess the risk posed by meteoroid streams. Previously, this forecast focused on the International Space Station and therefore reported ... More
Cumulative whistler instability in fast solar winds: Constraints of electron temperature anisotropyApr 12 2019Context. Solar outflows are a considerable source of free energy which accumulates in multiple forms like beaming (or drifting) components and/or temperature anisotropies. However, kinetic anisotropies of plasma particles do not grow indefinitely and ... More
Astro 2020 Science White Paper: Cosmic-ray Antinuclei as Messengers for Dark MatterApr 11 2019The origin of dark matter is a driving question of modern physics. Low-energy antideuterons provide a "smoking gun" signature of dark matter annihilation or decay, essentially free of astrophysical background. Low-energy antiprotons are a vital partner ... More
Diagnostics of Space Weather Drivers Enabled by Radio ObservationsApr 11 2019The Sun is an active star that can have a direct impact on the Earth, its magnetosphere, and the technological infrastructure on which modern society depends. Among the phenomena that drive "space weather" are fast solar wind streams and co-rotating interaction ... More
Medium Earth Orbit dynamical survey and its use in passive debris removalApr 11 2019The Medium Earth Orbit (MEO) region hosts satellites for navigation, communication, and geodetic/space environmental science, among which are the Global Navigation Satellites Systems (GNSS). Safe and efficient removal of debris from MEO is problematic ... More
Dynamics of electron beams in the solar corona plasma with density fluctuationsApr 11 2019The problem of beam propagation in a plasma with small scale and low intensity inhomogeneities is investigated. It is shown that the electron beam propagates in a plasma as a beam-plasma structure and is a source of Langmuir waves. The plasma inhomogeneity ... More
Dynamical Lifetime Survey of Geostationary Transfer OrbitsApr 11 2019In this paper, we study the long-term dynamical evolution of highly-elliptical orbits (HEOs) in the medium-Earth orbit (MEO) region around the Earth. The real population consists primarily of Geosynchronous Transfer Orbits (GTOs), launched at specific ... More
3D Reconstruction and Interplanetary Expansion of the 2010 April 3rd CMEApr 11 2019We analyse the 2010 April 3rd CME using spacecraft coronagraphic images at different vantage points (SOHO, STEREO-A and STEREO-B). We perform a 3D reconstruction of both the flux rope and shock using the Graduated Cylindrical Shell (GCS) model to calculate ... More
Testing the nature of dark compact objects: a status reportApr 10 2019Apr 16 2019Very compact objects probe extreme gravitational fields and may be the key to understand outstanding puzzles in fundamental physics. These include the nature of dark matter, the fate of spacetime singularities, or the loss of unitarity in Hawking evaporation. ... More
Testing the nature of dark compact objects: a status reportApr 10 2019Very compact objects probe extreme gravitational fields and may be the key to understand outstanding puzzles in fundamental physics. These include the nature of dark matter, the fate of spacetime singularities, or the loss of unitarity in Hawking evaporation. ... More
Forbush decreases and $<$ 2-day GCR flux non-recurrent variations studied with LISA PathfinderApr 09 2019Non-recurrent short term variations of the galactic cosmic-ray (GCR) flux above 70 MeV n$^{-1}$ were observed between 2016 February 18 and 2017 July 3 aboard the European Space Agency LISA Pathfinder (LPF) mission orbiting around the Lagrange point L1 ... More
Explicit IMF $B_y$-effect maximizes at subauroral latitudes (Dedicated to the memory of Eigil Friis-Christensen)Apr 09 2019The most important parameter in the coupling between solar wind and geomagnetic activity is the $B_z$-component of the interplanetary magnetic field (IMF). However, recent studies have shown that IMF $B_y$ is an additional, independent driver of geomagnetic ... More
Modelling H$_{3}^{+}$ in planetary atmospheres: effects of vertical gradients on observed quantitiesApr 08 2019Apr 10 2019Since its discovery in the aurorae of Jupiter ~30 years ago, the H$_{3}^{+}$ ion has served as an invaluable probe of giant planet upper atmospheres. However, the vast majority of monitoring of planetary H$_{3}^{+}$ radiation has followed from observations ... More
Modelling H$_{3}^{+}$ in planetary atmospheres: effects of vertical gradients on observed quantitiesApr 08 2019Since its discovery in the aurorae of Jupiter ~30 years ago, the H$_{3}^{+}$ ion has served as an invaluable probe of giant planet upper atmospheres. However, the vast majority of monitoring of planetary H$_{3}^{+}$ radiation has followed from observations ... More
Three-dimensional local anisotropy of velocity fluctuations in the solar windApr 08 2019We analyse velocity fluctuations in the solar wind at magneto-fluid scales in two datasets, extracted from Wind data in the period 2005-2015, that are characterised by strong or weak expansion. Expansion affects measurements of anisotropy because it breaks ... More
Spectral anisotropies and intermittency of plasma turbulence at ion kinetic scalesApr 08 2019Apr 17 2019By means of three dimensional high-resolution hybrid simulations we study the properties of the magnetic field spectral anisotropies near and beyond ion kinetic scales. By using both a Fourier analysis and a local analysis based on multi-point 2nd-order ... More
Spectral anisotropies and intermittency of plasma turbulence at ion kinetic scalesApr 08 2019By means of three dimensional high-resolution hybrid simulations we study the properties of the magnetic field spectral anisotropies near and beyond ion kinetic scales. By using both a Fourier analysis and a local analysis based on multi-point 2nd-order ... More
Time dependent solar modulation of cosmic rays from solar minimum to solar maximumApr 07 2019We study the time-dependent modulation effect and derive the local interstellar spectra (LIS) for the cosmic ray (CR) proton, helium, boron and carbon. A two-dimensional modulation model including the variation of the interplanetary environment with time ... More
Inferring source properties of monoenergetic electron precipitation from kappa and Maxwellian moment-voltage relationshipsApr 05 2019We present two case studies of FAST electrostatic analyzer measurements of both highly nonthermal ($\kappa \lesssim$~2.5) and weakly nonthermal/thermal monoenergetic electron precipitation at $\sim$4000~km, from which we infer the properties of the magnetospheric ... More
A Novel Ten-Moment Multifluid Model for Mercury: From the Planetary Conducting Core to the Dynamic MagnetosphereApr 04 2019We have developed a three-dimensional ten-moment multifluid model and applied it to investigate the tightly coupled interior-magnetosphere system of Mercury. This novel kinetic fluid model incorporates the non-ideal effects including the Hall effect, ... More
Interstellar medium parameters in front of the external bow shockApr 04 2019We know that it is the front of the bow shock where the solar wind kinetic energy flux is transformed into the other kinds the most intensively. In our previous studies, we obtained important relationships that enable calculating the key parameters at ... More
A violin sonata for reconnectionApr 03 2019The process of magnetic reconnection when studied in Nature or when modeled in 3D simulations differs in one key way from the standard 2D paradigmatic cartoon: it is accompanied by much fluctuations in the electromagnetic fields and plasma properties. ... More
Validation of the neutron monitor yield function using data from AMS-02 experiment, 2011--2017Apr 03 2019The newly published spectra of protons and helium over time directly measured in space by the AMS-02 experiment for the period 2011--2017 provide a unique opportunity to calibrate ground-based neutron monitors (NMs). Here, calibration of several stable ... More
Time-Dependent Two-Fluid Magnetohydrodynamic Model and Simulation of the ChromosphereApr 02 2019The sun's chromosphere is a highly dynamic, partially-ionized region where spicules (hot jets of plasma) form. Here we present a two-fluid MHD model to study the chromosphere, which includes ion-neutral interaction and frictional heating. Our simulation ... More
Towards a sustainable exploitation of the geosynchronous orbital regionMar 31 2019In this work the orbital dynamics of Earth satellites about the geosynchronous altitude are explored, with primary goal to assess current mitigation guidelines as well as to discuss the future exploitation of the region. A thorough dynamical mapping was ... More
Attitude and orbit coupling of planar helio-stable solar sailsMar 31 2019The coupled attitude and orbit dynamics of solar sails is studied. The shape of the sail is a simplified quasi-rhombic-pyramid that provides the structure helio-stablility properties. After adimensionalisation the system is put in the form of a fast-slow ... More
Simulating Solar Coronal Mass Ejections constrained by Observations of their Speed and Poloidal fluxMar 30 2019We demonstrate how the parameters of a Gibson-Low flux-rope-based coronal mass ejection (CME) can be constrained using remote observations. Our Multi Scale Fluid-Kinetic Simulation Suite (MS-FLUKSS) has been used to simulate the propagation of a CME in ... More
A Collision Probability Estimation Algorithm Used in the Space Debris Evolutionary ModelMar 29 2019An in-depth analysis is performed on the problem that one parameter of the Cube model can affects the final simulation results of space debris long-term evolution model, which weakens the representativeness of the space debris evolution model. We made ... More
Dynamics of Megaelectron Volt Electrons Observed in the Inner Belt by PROBA-V/EPTMar 28 2019Using the observations of the EPT (Energetic Particle Telescope) onboard the satellite PROBA-V we study the dynamics of inner and outer belt electrons from 500 keV to 8 MeV during quiet periods and geomagnetic storms. This high time-resolution (2 sec) ... More
An introduction to a new space debris evolution model -- SOLEMMar 28 2019SOLEM is the first space debris long-term evolution model of China. This paper describes the principles, components and workflow of the SOLEM. The effects of different mitigation measures based on SOLEM model are analyzed and presented. The limitation ... More
First observations of irregular surface of interplanetary shocks at ion scales by ClusterMar 27 2019We present the first observational evidence of the irregular surface of interplanetary (IP) shocks by using multi-spacecraft observations of the Cluster mission. In total we discuss observations of four IP shocks that exhibit moderate Alfv\'enic Mach ... More
Nonlinear Evolution of Ion Kinetic Instabilities in the Solar WindMar 27 2019In-situ observations of the solar wind (SW) plasma from 0.29 to 1AU show that the protons and alpha particles are often non-Maxwellian, with evidence of kinetic instabilities, temperature anisotropies, differential ion streaming, and associated magnetic ... More
Possible cool prominence materials detected within interplanetary small magnetic flux ropesMar 27 2019Previous studies indicate that interplanetary small magnetic flux ropes (SMFRs) are manifestations of microflare-associated small coronal mass ejections (CMEs), and the hot material with high charge states heated by related microflares are found in SMFRs. ... More
Small Interplanetary Magnetic Flux RopeMar 26 2019Small interplanetary magnetic flux ropes (SIMFRs) are often detected by space satellites in the interplanetary space near 1 AU. These ropes can be fitted by a cylindrically symmetric magnetic model. The durations of SIMFRsare usually <12 h, and the diameters ... More
Inverse magnetic energy cascades embedded in magnetohydrodynamical turbulenceMar 26 2019The existence of partially conserved enstrophy-like quantities is conjectured to cause embedded, inverse magnetic energy cascades to develop in magnetohydrodynamical (MHD) turbulence. By decomposing the velocity and magnetic fields in spectral space onto ... More
The effects of crustal magnetic fields and solar EUV flux on ionopause formation at MarsMar 25 2019We study the ionopause of Mars using a database of 6,893 ionopause detections obtained over 11 years by the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) radar sounder. The ionopause, in this work, is defined as a steep density gradient ... More
Concept study and preliminary design of a cold atom interferometer for space gravity gradiometryMar 23 2019We study a space-based gravity gradiometer based on cold atom interferometry and its potential for the Earth's gravitational field mapping. The instrument architecture has been proposed in [Carraz et al., Microgravity Science and Technology 26, 139 (2014)] ... More
Drift instabilities in thin current sheets using a two-fluid model with pressure tensor effectsMar 22 2019The integration of kinetic effects in fluid models is important for global simulations of the Earth's magnetosphere. We use a two-fluid ten moment model, which includes the pressure tensor and has been used to study reconnection, to study the drift kink ... More
Dynamic evolution of current sheets, ideal tearing, plasmoid formation and generalized fractal reconnection scaling relationsMar 22 2019Magnetic reconnection may be the fundamental process allowing energy stored in magnetic fields to be released abruptly, solar flares and coronal mass ejection (CME) being archetypal natural plasma examples. Magnetic reconnection is much too slow a process ... More
Interplanetary spread of solar energetic protons near a high-speed solar wind streamMar 21 2019We study how a high-speed solar wind stream embedded in a slow solar wind influences the spread of solar energetic protons in interplanetary space. To model the energetic protons, we used a recently developed particle transport code that computes particle ... More
Dynamics of electron beams in the inhomogeneous solar corona plasmaMar 21 2019Dynamics of an spatially limited electron beam in the inhomogeneous solar corona plasma is considered in the framework of weak turbulence theory when the temperature of the beam significantly exceeds that of surrounding plasma. The numerical solution ... More
Effect of rectangular grooves and checkerboard patterns on the electron emission yieldMar 21 2019The effect of rough structures on the electron emission under electron impact between 10 eV and 2 keV is investigated with a new version of the low energy electromagnetic model of GEANT4 (MicroElec). The inelastic scattering is modeled, thanks to the ... More
Forecasting of the Thermosphere via Assimilation of Electron Density and Temperature DataMar 20 2019The paper presents experiments of driving a physics-based thermosphere model by assimilating electron density (Ne) and temperature (Tn) data using the ensemble adjustment Kalman filter (EAKF) technique. This study not only helps to gauge the accuracy ... More
Numerical consideration of quasilinear electron cloud dynamics in plasmaMar 20 2019The dynamics of a hot electron cloud in the solar corona-like plasma based on the numerical solution of kinetic equations of weak turbulence theory is considered. Different finite difference schemes are examined to fit the exact analytical solutions of ... More
Nonlinear development of electron-beam-driven weak turbulence in an inhomogeneous plasmaMar 20 2019The self-consistent description of Langmuir wave and ion-sound wave turbulence in the presence of an electron beam is presented for inhomogeneous non-isothermal plasmas. Full numerical solutions of the complete set of kinetic equations for electrons, ... More
The solar fast dynamo action extended to A, Ap and Am type starsMar 18 2019Initially, we present our original fast dynamo mechanism being potentially at work concerning the Sun and the solar type stars. Then, based on this new prototype model, a dynamo action model explaining the generation of the magnetic fields for A, Ap and ... More
The HelMod Model in the Works for Inner and Outer Heliosphere: from AMS to Voyager Probes ObservationsMar 18 2019HelMod is a Monte Carlo code developed to describe the transport of Galactic Cosmic Rays (GCRs) through the heliosphere from the interstellar space to the Earth. In the current HelMod version 4 the modulation process, based on Parker's equation, is applied ... More
[Plasma 2020 Decadal] The essential role of multi-point measurements in turbulence investigations: the solar wind beyond single scale and beyond the Taylor HypothesisMar 16 2019This paper briefly reviews a number of fundamental measurements that need to be made in order to characterize turbulence in space plasmas such as the solar wind. It has long been known that many of these quantities require simultaneous multipoint measurements ... More
An extended MHD study of the 16 October 2015 MMS diffusion region crossingMar 15 2019The Magnetospheric Multiscale (MMS) mission has given us unprecedented access to high cadence particle and field data of magnetic reconnection at Earth's magnetopause. MMS first passed very near an X-line on 16 October 2015, the Burch event, and has since ... More
[Plasma 2020 Decadal] Multipoint Measurements of the Solar Wind: A Proposed Advance for Studying Magnetized TurbulenceMar 13 2019A multi-institutional, multi-national science team will soon submit a NASA proposal to build a constellation of spacecraft to fly into the near-Earth solar wind in a swarm spanning a multitude of scales in order to obtain critically needed measurements ... More
[Plasma 2020 Decadal] Disentangling the Spatiotemporal Structure of Turbulence Using Multi-Spacecraft DataMar 13 2019This white paper submitted for 2020 Decadal Assessment of Plasma Science concerns the importance of multi-spacecraft missions to address fundamental questions concerning plasma turbulence. Plasma turbulence is ubiquitous in the universe, and it is responsible ... More
Assessment of the Radiation Environment at Commercial Jet Flight Altitudes During GLE 72 on 10 September 2017 Using Neutron Monitor DataMar 13 2019As a result of intense solar activity during the first ten days of September, a ground level enhancement occurred on September 10, 2017. Here we computed the effective dose rates in the polar region at several altitudes during the event using the derived ... More
The Challenge of Machine Learning in Space Weather Nowcasting and ForecastingMar 12 2019The numerous recent breakthroughs in machine learning (ML) make imperative to carefully ponder how the scientific community can benefit from a technology that, although not necessarily new, is today living its golden age. This review paper is focused ... More
Near-Earth Supernova Explosions: Evidence, Implications, and OpportunitiesMar 11 2019There is now solid experimental evidence of at least one supernova explosion within 100 pc of Earth within the last few million years, from measurements of the short-lived isotope 60Fe in widespread deep-ocean samples, as well as in the lunar regolith ... More
Lightning and charge processes in brown dwarf and exoplanet atmospheresMar 11 2019Mar 13 2019The study of the composition of brown dwarf atmospheres helped to understand their formation and evolution. Similarly, the study of exoplanet atmospheres is expected to constrain their formation and evolutionary states. We use results from 3D simulations, ... More
Proton-proton collisions in the turbulent solar wind: Hybrid Boltzmann-Maxwell simulationsMar 08 2019The mechanism of heating for hot, dilute and turbulent plasmas represents a long-standing problem in space physics, whose implications concern both near-Earth environments and astrophysical systems. Here, in order to explore the possible role of inter-particle ... More
An automated approach for photometry and dust mass calculation of the Crab nebulaMar 08 2019Ample evidence exists regarding supernovae being a major contributor to interstellar dust. In this work, the deepest far-infrared observations of the Crab Nebula are used to revisit the estimation of} the dust mass present in this supernova remnant. Images ... More
Theory of Stochastic Shock Drift Acceleration for Electrons in the Shock Transition RegionMar 06 2019We propose a novel electron acceleration mechanism, which we call stochastic shock drift acceleration (SSDA), that extends the standard shock drift acceleration (SDA) for low-energy electrons at a quasi-perpendicular shock to include the effect of stochastic ... More
First observations of an ICME compressing Mercury's dayside magnetosphere to the surfaceMar 01 2019Mercury is the only planet in the inner solar system, other than Earth, that possesses a dynamo-generated global, albeit weak, magnetic field. As a consequence of this weak field and the planet's proximity to the Sun, the magnetosphere of Mercury is highly ... More
Mars Missions Failure Report Assortment : Review and ConspectusMar 01 2019Mars has been successfully explored by various space firms. Globally, 44 mission attempts were made and lamentably 27 encountered ineffective. There have been instances where a small misstep in the progressive accomplishment of spaceflight sequence may ... More
Interstellar Dust in the Solar System: Model versus In-Situ Spacecraft DataMar 01 2019In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in-situ dust detector on board the Ulysses spacecraft. Later on, interstellar dust was also identified in the data sets measured with dust ... More
2X8 Multilayer Microstrip Patch Array Antenna for C-Band Radar Micro-SARMar 01 2019A Microstrip patch array antenna has been designed for 5.62 GHz on FR4 substrate having a dielectric constant of 4.4 and thickness is 1.6 mm.The antenna is used to design for use with a low cost imaging radar MicroSAR. The antenna composed of an array ... More
Solar flares observed by Rosetta at comet 67PFeb 28 2019Context. The Rosetta spacecraft made continuous measurements of the coma of comet 67P/ Churyumov-Gerasimenko (67P) for more than two years. The plasma in the coma appeared very dynamic, and many factors control its variability. Aims. We wish to identify ... More
Comparative Study of Microwave Polar Brightening, Coronal Holes, and Solar Wind Over the Solar PolesFeb 28 2019We comparatively studied the long-term variation (1992-2017) in polar brightening observed with the Nobeyama Radioheliograph, the polar solar wind velocity with interplanetary scintillation observations at the Institute for Space-Earth Environmental Research, ... More
New very local interstellar spectra for electrons, positrons, protons and light cosmic ray nucleiFeb 27 2019The local interstellar spectra (LIS's) for galactic cosmic rays (CR's) cannot be directly observed at the Earth below certain energies, because of solar modulation in the heliosphere. With Voyager 1 crossing the heliopause in 2012, in situ experimental ... More
Predicting the Structure of the Solar Corona and Inner Heliosphere during Parker Solar Probe's First Perihelion PassFeb 26 2019NASA's Parker Solar Probe (Parker) spacecraft reached its first perihelion of 35.7 solar radii on November 5th, 2018. To aid in mission planning, and in anticipation of the unprecedented measurements to be returned, in late October, we developed a three-dimensional ... More
Inhomogeneity Generated Waves in Pressure Balanced StructuresFeb 25 2019Inhomogeneity generated waves, discovered more than a decade ago, play an important role in processes like energy transfer, turbulence generation, heating, etc. To understand the nature of these waves we developed the formalism that looks for the short-term ... More
Suzaku detection of enigmatic geocoronal solar wind charge exchange event associated with coronal mass ejectionFeb 19 2019Suzaku detected an enhancement of soft X-ray background associated with solar eruptions on 2013 April 14-15. The solar eruptions were accompanied by an M6.5 solar flare and a coronal mass ejection with magnetic flux ropes. The enhanced soft X-ray background ... More
Full inversion of solar relativistic electron events measured by the Helios spacecraftFeb 18 2019Up to present, the largest data set of SEP events in the inner heliosphere are the observations by the two Helios spacecraft. We re-visit a sample of 15 solar relativistic electron events measured by the Helios mission with the goal of better characterising ... More
Full inversion of solar relativistic electron events measured by the Helios spacecraftFeb 18 2019Feb 19 2019Up to present, the largest data set of SEP events in the inner heliosphere are the observations by the two Helios spacecraft. We re-visit a sample of 15 solar relativistic electron events measured by the Helios mission with the goal of better characterising ... More
The Efficiency of Coherent Radiation from Relativistic ShocksFeb 17 2019We discuss a mechanism for intense electromagnetic wave emission at an astrophysical relativistic shock in a magnetized collisionless plasma. At the magnetized shock, the particle reflection by a compressed magnetic field of the shock produces a ring-like ... More
Evidence for Electron Landau Damping in Space Plasma TurbulenceFeb 15 2019How turbulent energy is dissipated in weakly collisional space and astrophysical plasmas is a major open question. Here, we present the application of a field-particle correlation technique to directly measure the transfer of energy between the turbulent ... More
The solution of the Generalized Kepler's equationFeb 14 2019In the context of general perturbation theories, the main problem of the artificial satellite analyses the motion of an orbiter around an Earth-like planet, only perturbed by its equatorial bulge or J2 effect. By means of a Lie transform and the Krylov-Bogoliubov-Mitropolsky ... More
Forecasting satellite trajectories by interpolating hybrid orbit propagatorsFeb 14 2019A hybrid orbit propagator based on the analytical integration of the Kepler problem is designed to determine the future position and velocity of any orbiter, usually an artificial satellite or space debris fragment, in two steps: an initial approximation ... More
Solar wind charge exchange in cometary atmospheres. I. Charge-changing and ionization cross sections for He and H particles in H$_2$OFeb 13 2019Solar wind charge-changing reactions are of paramount importance to the physico-chemistry of the atmosphere of a comet, mass-loading the solar wind through an effective conversion of fast light solar wind ions into slow heavy cometary ions. To understand ... More
Project Lyra: Catching 1I/'Oumuamua - Mission Opportunities After 2024Feb 13 2019In October 2017, the first interstellar object within our solar system was discovered. Today designated 1I/'Oumuamua, it shows characteristics that have never before been observed in a celestial body. Due to these characteristics, an in-situ investigation ... More
Self-similar expansion model of cylindrical flux ropes combined with Alfven wave current systemFeb 13 2019Magnetic flux ropes in space are generally connected to some regions electromagnetically. We consider the whole closed current system of the expanding flux ropes including the electric current associated with them. By combining the theories regarding ... More
Direct observations of a surface eigenmode of the dayside magnetopauseFeb 12 2019The abrupt boundary between a magnetosphere and the surrounding plasma, the magnetopause, has long been known to support surface waves. It was proposed that impulses acting on the boundary might lead to a trapping of these waves on the dayside by the ... More
Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-GerasimenkoFeb 12 2019Solar wind charge-changing reactions are of paramount importance to the physico-chemistry of the atmosphere of a comet. The ESA/Rosetta mission to comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in ... More
Two-Line Element Estimation From Space Catalog Using Machine LearningFeb 11 2019Two-line elements are widely used for space operations to predict the orbit with a moderate accuracy for 2-3 days. Local optimization methods, such as the nonlinear least squares method with differential corrections, can estimate a TLE as long as there ... More
Low Cost Radiation Hardened Software and Hardware Implementation for CubeSatsFeb 11 2019CubeSats are small satellites used for scientific experiments because they cost less than full sized satellites. Each CubeSat uses an on-board computer. The on-board computer performs sensor measurements, data processing, and CubeSat control. The challenges ... More
Spectral Analysis of the September 2017 Solar Energetic Particle EventsFeb 11 2019An interval of exceptional solar activity was registered in early September 2017, late in the decay phase of solar cycle 24, involving the complex Active Region 12673 as it rotated across the western hemisphere with respect to Earth. A large number of ... More
Stellar energetic particles in the magnetically turbulent habitable zones of TRAPPIST-1-like planetary systemsFeb 11 2019Planets in close proximity to their parent star, such as those in the habitable zones around M dwarfs, could be subject to particularly high doses of particle radiation. We have carried out test-particle simulations of ~GeV protons to investigate the ... More
The multi-scale nature of the solar windFeb 09 2019The solar wind is a magnetized plasma and as such exhibits collective plasma behavior associated with its characteristic spatial and temporal scales. The characteristic length scales include the size of the heliosphere, the collisional mean free paths ... More
A Comparative Study of 2017 July and 2012 July Complex Eruptions: Are Solar Superstorms "Perfect Storms" in Nature?Feb 09 2019It is paramount from both scientific and societal perspectives to understand the generation of extreme space weather. We discuss the formation of solar superstorms based on a comparative study of the 2012 July 23 and 2017 July 23 eruptions. The first ... More
Contextual Predictions for Parker Solar Probe II: Turbulence Properties and Taylor HypothesisFeb 09 2019The Parker Solar Probe (PSP) primary mission extends seven years and consists of 24 orbits of the Sun with descending perihelia culminating in a closest approach of ($\sim 9.8~R_\odot$). In the course of these orbits PSP will pass through widely varying ... More
Predictions for the First Parker Solar Probe EncounterFeb 08 2019We examine Alfv\'en Wave Solar atmosphere Model (AWSoM) predictions of the first Parker Solar Probe (PSP) encounter. We focus on the 12-day closest approach centered on the 1st perihelion. AWSoM (van der Holst et al., 2014) allows us to interpret the ... More
A new HLLD Riemann solver with Boris correction for reducing Alfvén speedFeb 07 2019Mar 03 2019A new Riemann solver is presented for the ideal magnetohydrodynamics (MHD) equations with the so-called Boris correction. The Boris correction is applied to reduce wave speeds, avoiding an extremely small timestep in MHD simulations. The proposed Riemann ... More
A new HLLD Riemann solver with Boris correction for reducing Alfvén speedFeb 07 2019A new Riemann solver is presented for the ideal magnetohydrodynamics (MHD) equations with the so-called Boris correction. The Boris correction is applied to reduce wave speeds, avoiding an extremely small timestep in MHD simulations. The proposed Riemann ... More