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Related papers: Solar Energetic Particle drifts in the Parker spir…

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Drifts are known to play a role in galactic cosmic ray transport within the heliosphere and are a standard component of cosmic ray propagation models. However, the current paradigm of Solar Energetic Particle (SEP) propagation holds the…

Solar and Stellar Astrophysics · Physics 2013-08-30 M. S. Marsh , S. Dalla , J. Kelly , T. Laitinen

We investigate the deceleration of Solar Energetic Particles (SEPs) during their propagation from the Sun through interplanetary space, in the presence of weak to strong scattering in a Parker spiral configuration, using relativistic full…

Solar and Stellar Astrophysics · Physics 2015-08-17 S. Dalla , M. S. Marsh , T. Laitinen

The event-averaged charge state of heavy ion Solar Energetic Particles (SEPs), measured at 1 AU from the Sun, typically increases with the ions' kinetic energy. The origin of this behaviour has been ascribed to processes taking place within…

Space Physics · Physics 2017-02-08 S. Dalla , M. S. Marsh , M. Battarbee

Particle drifts perpendicular to the background magnetic field have been proposed by some authors as an explanation for the very efficient perpendicular transport of solar energetic particles (SEPs). This process, however, competes with…

Space Physics · Physics 2021-12-07 J. P. van den Berg , N. E. Engelbrecht , N. Wijsen , R. D. Strauss

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 turbulence and spatial nonuniformity of the guide magnetic field cause two competitive effects, namely, the scattering effect and the adiabatic focusing effect, respectively. In this work, we numerically solve the five-dimensional…

Space Physics · Physics 2019-11-11 H. -Q. He , W. Wan

Context. The intensity profiles of iron and oxygen in Solar Energetic Particle (SEP) events often display differences that result in a decreasing Fe/O ratio over time. The physical mechanisms behind this behaviour are not fully understood,…

Solar and Stellar Astrophysics · Physics 2017-02-08 S. Dalla , M. S. Marsh , P. Zelina , T. Laitinen

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

Solar energetic particles (SEPs), accelerated during solar eruptions, propagate in turbulent solar wind before being observed with in situ instruments. In order to interpret their origin through comparison with remote-sensing observations…

Solar and Stellar Astrophysics · Physics 2020-01-08 T. Laitinen , S. Dalla

The gradient and curvature of the Parker spiral interplanetary magnetic field give rise to curvature and gradient guiding centre drifts on cosmic rays. The plasma turbulence present in the interplanetary space is thought to suppress the…

Solar and Stellar Astrophysics · Physics 2024-12-19 T. Laitinen , S. Dalla

Solar energetic particles (SEPs), accelerated during solar eruptions, are observed to rapidly reach a wide heliolongitudinal range in the interplanetary space. To access these locations, the SEPs must have either been accelerated at a wide…

Solar and Stellar Astrophysics · Physics 2023-05-17 T. Laitinen , S. Dalla , C. O. G. Waterfall , A. Hutchinson

Recent observations have shown that coronal shocks driven by coronal mass ejections can develop and accelerate particles within several solar radii in large solar energetic particle (SEP) events. Motivated by this, we present an SEP…

Solar and Stellar Astrophysics · Physics 2017-12-20 Xiangliang Kong , Fan Guo , Joe Giacalone , Hui Li , Yao Chen

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

We model the transport of solar energetic particles (SEPs) in the solar wind. We propagated relativistic test particles in the field of a steady three-dimensional magnetohydrodynamic simulation of the solar wind. We used the code MPI-AMRVAC…

Solar and Stellar Astrophysics · Physics 2025-02-19 Houeibib Ahmed , Pantellini Filippo , Griton Lea

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

Context. Solar Energetic Particles (SEPs) with energy in the GeV range can propagate to Earth from their acceleration region near the Sun and produce Ground Level Enhancements (GLEs). The traditional approach to interpreting and modelling…

Solar and Stellar Astrophysics · Physics 2020-08-04 S. Dalla , G. De Nolfo , A. Bruno , J. Giacalone , T. Laitinen , S. Thomas , M. Battarbee , M. S. Marsh

Recent modelling of solar energetic particles (SEPs) propagation through the heliospheric turbulence, also discussed in this workshop, has investigated the role of the pitch-angle scattering and the perpendicular transport in spreading…

Solar and Stellar Astrophysics · Physics 2015-12-31 F. Fraschetti

In-situ measurements by several spacecraft have revealed that the solar wind is frequently perturbed by transient structures (magnetic folds, jets, waves, flux-ropes) that propagate rapidly away from the Sun over large distances. Parker…

Solar and Stellar Astrophysics · Physics 2021-09-15 R. F. Pinto , N. Poirier , A. P. Rouillard , A. Kouloumvakos , L. Griton , N. Fargette , R. Kieokaew , B. Lavraud , A. S. Brun

A functional form I_{max}(R)=kR^{-\alpha}, where R is the radial distance of spacecraft, was usually used to model the radial dependence of peak intensities I_{max}(R) of solar energetic particles (SEPs). In this work, the five-dimensional…

Space Physics · Physics 2017-06-20 H. -Q. He , G. Zhou , W. Wan

We present a 2D kinematic model to study the acceleration of solar energetic particles (SEPs) at a shock driven by a coronal mass ejection. The shock is assumed to be spherical about an origin that is offset from the center of the Sun. This…

Solar and Stellar Astrophysics · Physics 2023-06-27 Xiaohang Chen , Joe Giacalone , Fan Guo
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