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Title: Cosmic ray transport in heliospheric magnetic structures. I. Modeling background solar wind using the CRONOS magnetohydrodynamic code

The transport of energetic particles such as cosmic rays is governed by the properties of the plasma being traversed. While these properties are rather poorly known for galactic and interstellar plasmas due to the lack of in situ measurements, the heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric transport of energetic particles are structures such as corotating interaction regions, which, due to strongly enhanced magnetic field strengths, turbulence, and associated shocks, can act as diffusion barriers on the one hand, but also as accelerators of low energy CRs on the other hand as well. In a two-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with a numerical magnetohydrodynamic (MHD) setup (this paper), which will serve as an input to a transport code employing a stochastic differential equation approach (second paper). In this first paper, we present results from 3D MHD simulations with our code CRONOS: for validation purposes we use analytic boundary conditions and compare with similar work by Pizzo. For a more realistic modeling of solar wind conditions, boundary conditions derived from synoptic magnetogramsmore » via the Wang-Sheeley-Arge (WSA) model are utilized, where the potential field modeling is performed with a finite-difference approach in contrast to the traditional spherical harmonics expansion often utilized in the WSA model. Our results are validated by comparing with multi-spacecraft data for ecliptical (STEREO-A/B) and out-of-ecliptic (Ulysses) regions.« less
Authors:
; ;  [1] ; ; ;  [2] ;  [3]
  1. Institut für Theoretische Physik IV, Ruhr-Universität Bochum (Germany)
  2. Institut für Experimentelle und Angewandte Physik, Christian-Albrecht-Universität zu Kiel (Germany)
  3. Institut für Astro- und Teilchenphysik, Universität Innsbruck (Austria)
Publication Date:
OSTI Identifier:
22356641
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 788; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BOUNDARY CONDITIONS; COMPARATIVE EVALUATIONS; COSMIC RADIATION; DIFFERENTIAL EQUATIONS; DIFFUSION BARRIERS; HELIOSPHERE; INTERACTIONS; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; PLASMA; SHOCK WAVES; SIMULATION; SOLAR WIND; SPHERICAL HARMONICS; STOCHASTIC PROCESSES; SUN; THREE-DIMENSIONAL CALCULATIONS; TRANSPORT THEORY; TURBULENCE