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Related papers: Spreading protons in the heliosphere: a note on cr…

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Impulsive solar energetic electrons are often observed in the interplanetary space near the Earth and have an attractive diagnostic potential for poorly understood solar flare acceleration processes. We investigate the transport of solar…

Solar and Stellar Astrophysics · Physics 2009-11-13 E. P. Kontar , H. A. S. Reid

The Sun drives a supersonic wind which inflates a giant plasma bubble in our very local interstellar neighborhood, the heliosphere. It is bathed in an extremely variable background of energetic ions and electrons which originate from a…

The topic of this review paper is on the influence of solar wind turbulence on shock propagation and its consequence on the acceleration and transport of energetic particles at shocks. As the interplanetary shocks sweep through the…

Solar and Stellar Astrophysics · Physics 2021-02-12 Fan Guo , Joe Giacalone , Lulu Zhao

The processes responsible for the effective longitudinal transport of solar energetic particles (SEPs) are still not completely understood. We address this issue by simulating SEP electron propagation using a spatially 2D transport model…

Solar and Stellar Astrophysics · Physics 2018-04-12 R. D. Strauss , N. Dresing , N. E. Engelbrecht

Proton and alpha particle collisional transport coefficients (isotropization, relative deceleration frequencies and heating rates) at 1 AU are quantified using the WIND/SWE data. In agreement with previous studies the ion-ion Coulomb…

Space Physics · Physics 2016-08-04 Petr Hellinger

The solar wind affects the plasma environment around all solar system bodies. A strong solar wind dynamic pressure pushes plasma boundaries closer to these objects. For small objects kinetic effects on scales smaller than an ion gyroradius…

The effect of solar rotation on the proton-alpha differential flow speed, $v_{\alpha p}$, and consequently on the angular momentum transport in the solar wind, is explored. It is found that the force introduced by the azimuthal components…

Astrophysics · Physics 2011-02-11 Bo Li , Shadia Rifai Habbal , Xing Li

The trajectories of Solar Energetic Particles (SEPs) in an Interplanetary Magnetic Field (IMF) exhibiting large-scale fluctuations due to footpoint motions originating in the photosphere, are simulated using a full-orbit test-particle code.…

Solar and Stellar Astrophysics · Physics 2015-06-04 James Kelly , Silvia Dalla , Timo Laitinen

The multitude of recent multi-point spacecraft observations of solar energetic particle (SEP) events have made it possible to study the longitudinal distribution of SEPs in great detail. SEPs, even those accelerated during impulsive events,…

Solar and Stellar Astrophysics · Physics 2018-04-12 R. D. Strauss , H. Fichtner

After introduction we focus on: the transport of charged particles, the acceleration of ions at shocks, and the acceleration of electrons at shocks. Chapter 2 studies the propagation of solar energetic particles(SEPs) in turbulent magnetic…

High Energy Astrophysical Phenomena · Physics 2012-11-16 Fan Guo

Although the enhancements in the alpha-proton ratio in the solar wind (expressed as $A_{He} = N_a/N_p*100$) in the Interplanetary Coronal Mass Ejections (ICMEs) have been studied in the past, $A_{He}$ enhancements at the stream interface…

Solar and Stellar Astrophysics · Physics 2023-08-09 Yogesh , D. Chakrabarty , Nandita Srivastava

Modeling fast solar wind based on the kinetic theory is an important task for scientists. In this paper, we present a two-fluid model for fast solar wind with anisotropic Kappa-Maxwellian electrons and Bi-Maxwellian protons. In the…

Space Physics · Physics 2019-09-25 Somayeh Taran , Hossein Safari , Farhad Daei

Cosmic rays (CRs) are tracers of solar events when they are associated with solar flares, but also galactic events when they come from outside our solar system. SEPs are correlated with the 11-year solar cycle while GCRs are anti-correlated…

Solar and Stellar Astrophysics · Physics 2020-10-06 Barbara Perri , Allan Sacha Brun , Antoine Strugarek , Victor Réville

Context. Current solar energetic particle (SEP) propagation models describe the effects of interplanetary plasma turbulence on SEPs as diffusion, using a Fokker-Planck (FP) equation. However, FP models cannot explain the observed fast…

Solar and Stellar Astrophysics · Physics 2016-06-08 T. Laitinen , A. Kopp , F. Effenberger , S. Dalla , M. S. Marsh

We investigate the propagation of high-speed solar wind streams from their origin near the Sun to 1 AU using three-dimensional magnetohydrodynamic simulations. By tracking both global stream structure and individual plasma parcels, we…

Solar and Stellar Astrophysics · Physics 2026-05-05 Stefan J. Hofmeister

We study the effect of the magnetic gradient and curvature drifts on the pitch-angle dependent transport of solar energetic particles (SEPs), focusing on 3 - 36 MeV protons. By considering observers located at various positions in the…

Space Physics · Physics 2020-02-12 Nicolas Wijsen , Angels Aran , Blai Sanahuja , Jens Pomoell , Stefaan Poedts

The physical processes in the solar corona that shape the solar wind remain an active research topic. Modeling efforts have shown that energy and plasma exchanges near the transition region plays a crucial role in modulating solar wind…

Solar wind electron velocity distributions at 1 au consist of a thermal "core" population and two suprathermal populations: "halo" and "strahl". The core and halo are quasi-isotropic, whereas the strahl typically travels radially outwards…

Spacecraft observations have shown that the proton temperature in the solar wind falls off with radial distance more slowly than expected for an adiabatic prediction. Usually, previous studies have been focused on the evolution of the…

Space Physics · Physics 2018-12-19 D. Perrone , D. Stansby , T. Horbury , L. Matteini

Propagation of energetic particles across the mean field direction in turbulent magnetic fields is often described as spatial diffusion. Recently, it has been suggested that initially the particles propagate systematically along meandering…

Space Physics · Physics 2017-06-22 T. Laitinen , S. Dalla , D. Marriott