Theory and Transport of Nearly Incompressible Magnetohydrodynamic Turbulence: High Plasma Beta Regime

ORAL

Abstract

Nearly incompressible magnetohydrodynamic (NI MHD) theory for β ∼ 1 (or β << 1) plasma has been developed and applied to the study of solar wind turbulence. The leading order term in β ∼ 1 or β << 1 plasma describes majority 2D turbulence, while the higher-order term describes a minority slab turbulence. Here, we develop new NI MHD turbulence transport model equations in the high plasma beta regime. The leading order term in a β >> 1 plasma is fully incompressible and admits both structures (flux ropes or magnetic islands) and slab (Alfvén waves) fluctuations. This paper couples the NI MHD turbulence transport equations with a three fluid (proton, electron and pickup ion) equations, and solves the 1D steady-state equations from 1 au to 75 au. The model is tested against 27 years of Voyager 2 data, and Ulysses and NH SWAP data. The results agree remarkably well, with some scatter, about the theoretical predictions.

*We acknowledge the partial support of a Parker Solar Probe contract SV4-84017, an NSF EPSCoR RII-Track-1 cooperative agreement OIA-1655280, and NASA awards 80NSSC20K1783 and 80NSSC21K1319, and NASA Heliospheric Shield 80NSSC22M0164, and the SWAP instrument effort on the New Horizons project (M99023MJM; PU-A WD1006357), with support from NASA's New Frontiers Program and the IMAP mission as a part of NASA's Solar Terrestrial Probes (STP) mission line (80GSFC19C0027). A.P. acknowledges the partial support by the Czech Grant Agency under contract (23-06401S).

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Publication: Adhikari, L., Zank, G. P., Wang, B., et al. 2023, ApJ (in press)

Presenters

  • Laxman Adhikari

    • Department of Space Science and Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, USA
    • The University of Alabama in Huntsville

Authors

  • Laxman Adhikari

    • Department of Space Science and Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, USA
    • The University of Alabama in Huntsville

  • Gary P Zank

    • University of Alabama in Huntsville
    • Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899, USA

  • Bingbing Wang

    • University of Alabama in Huntsville

  • Lingling Zhao

    • The university of Alabama in Huntsville

  • Daniele Telloni

    • National Institute for Astrophysics—Astrophysical Observatory of Torino Via Osservatorio 20, I-10025 Pino Torinese, Italy

  • Alex Pitna

    • Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, Prague, Czechia
    • Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Prague 8, Czech Republic

  • Merav Opher

    • Astronomy Department, Boston University, Boston, MA 02115, USA
    • Boston University

  • Bishwas Shrestha

    • Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA

  • David J McComas

    • Princeton University
    • Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA

  • Katariina Nykyri

    • Embry-Riddle Aeronautical University, Daytona Beach
    • Department of Physical Sciences and Centre for Space and Atmospheric Research, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114, USA
    • Embry-Riddle Aeronautical University

  • Laxman Adhikari

    • Department of Space Science and Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, USA
    • The University of Alabama in Huntsville