Inertial Kinetic-Alfven Turbulence in a Space Plasma
ORAL
Abstract
Observations and analytical models indicate that the electron plasma beta parameter (ratio of the thermal to magnetic energy) becomes relatively small at low heliospheric distances, in the regions close to the solar corona, βe << βi ≤ 1. In such a regime, which is also encountered in the Earth’s magnetosheath and other astrophysical systems, kinetic-scale turbulence may be governed by the so-called inertial kinetic-Alfven modes [1,2]. We discuss the properties of this new regime of nonlinear plasma dynamics, present a phenomenological model of inertial kinetic-Alfven turbulence, and demonstrate that the results are in good agreement with the recent kinetic numerical simulations [3].
[1] Chen, C. H. K. & Boldyrev, S. Astrophys. J. 842 (2017) 122;
[2] Passot, T., Sulem, P. L., Tassi, E., Phys. Plasmas 25 (2018) 045107;
[3] Roytershteyn, V., Boldyrev, S., Delzanno, G. L., Chen, C. H. K., Grošelj, D., and Loureiro, N. F., Astrophys. J., 2018 (submitted).
*SB was partly supported by the NSF grant No. PHY-1707272, NASA grant No. 80NSSC18K0646 and by the Vilas Associates Award from the University of Wisconsin - Madison. VR was partly supported by NASA grant NNX15AR16G. CHKC was supported by STFC Ernest Rutherford Fellowship.
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Presenters
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Stanislav A Boldyrev
- Univ of Wisconsin, Madison, Space Science Institute, Boulder, CO 80301, USA
- Univ of Wisconsin, Madison