Search Publications
The Steady Global Corona and Solar Wind: A Three-dimensional MHD Simulation with Turbulence Transport and Heating
Matthaeus, William H.; Goldstein, Melvyn L.; Usmanov, Arcadi V. +1 more
We present a fully three-dimensional magnetohydrodynamic model of the solar corona and solar wind with turbulence transport and heating. The model is based on Reynolds-averaged solar wind equations coupled with transport equations for turbulence energy, cross helicity, and correlation scale. The model includes separate energy equations for protons…
An Unusual Energetic Particle Flux Enhancement Associated with Solar Wind Magnetic Island Dynamics
Chen, Y.; Zank, G. P.; Zhao, L. -L. +4 more
The possibility that charged particles are accelerated statistically in a “sea” of small-scale interacting magnetic flux ropes in the supersonic solar wind is gaining credence. In this Letter, we extend the Zank et al. statistical transport theory for a nearly isotopic particle distribution by including an escape term corresponding to particle los…
On the 1/f Spectrum in the Solar Wind and Its Connection with Magnetic Compressibility
Matteini, L.; Horbury, T. S.; Chen, C. H. K. +1 more
We discuss properties of Alfvénic fluctuations with large amplitude in plasmas characterized by low magnetic field compression. We note that in such systems power laws cannot develop with arbitrarily steep slopes at large scales, i.e., when | δ {\boldsymbol{B}}| becomes of the order of the background field | {\boldsymbol{B}}| . In such systems the…
HelMod in the Works: From Direct Observations to the Local Interstellar Spectrum of Cosmic-Ray Electrons
Jóhannesson, G.; Moskalenko, I. V.; Porter, T. A. +11 more
The local interstellar spectrum (LIS) of cosmic-ray (CR) electrons for the energy range 1 MeV to 1 TeV is derived using the most recent experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HELMOD, are combined to provide a single framework that…
Modulation of Galactic Cosmic Rays in the Inner Heliosphere over Solar Cycles
Qin, G.; Shen, Z. -N.
The 11- and 22-year modulation of galactic cosmic rays (GCRs) in the inner heliosphere is studied using a numerical model developed by Qin and Shen in 2017. Based on the numerical solutions of Parker’s transport equations, the model incorporates a modified Parker heliospheric magnetic field, a locally static time-delayed heliosphere, and a time-de…
3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?
Grappin, Roland; Alexandrova, Olga; Verdini, Andrea +1 more
We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansio…
Weakened Magnetization and Onset of Large-scale Turbulence in the Young Solar Wind—Comparisons of Remote Sensing Observations with Simulation
Parashar, Tulasi N.; Matthaeus, William H.; Goldstein, Melvyn L. +3 more
Recent analysis of Solar-Terrestrial Relations Observatory (STEREO) imaging observations have described the early stages of the development of turbulence in the young solar wind in solar minimum conditions. Here we extend this analysis to a global magnetohydrodynamic (MHD) simulation of the corona and solar wind based on inner boundary conditions,…
Lithium and Beryllium Isotopes with the PAMELA Experiment
Castellini, G.; Sarkar, R.; Ricci, M. +56 more
The cosmic ray (CR) lithium and beryllium (6Li, 7Li, 7Be, 9Be, 10Be) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on board the Resurs-DK1 satellite on 2006 June 15. The rare lithium and beryllium isotopes in CRs are …
On the Full-range β Dependence of Ion-scale Spectral Break in the Solar Wind Turbulence
He, Jiansen; Wang, Xin; Wang, Linghua +1 more
The power spectrum of magnetic fluctuations has a break at the high-frequency end of the inertial range. Beyond this break, the spectrum becomes steeper than the Kolmogorov law f -5/3. The break frequency was found to be associated with plasma beta (β). However, the full-range β dependence of the ion-scale spectral break has not been pr…