Turbulence and wave transmission at an ICME-driven shock observed by the Solar Orbiter and Wind

ORAL

Abstract

Interplanetary shocks in the heliosphere have important consequences for the generation and evolution of solar wind turbulence. The direct effects of shock waves on nearby turbulence remains a controversial issue. An interplanetary coronal mass ejection (ICME) event was observed by the Solar Orbiter at 0.8 AU on 2020 April 19 and wind at 1 AU on 2020 April 20. Furthermore, an interplanetary shock wave was driven in front of the ICME. In this talk, we focus on the transmission of the magnetic fluctuations across the shock and analyze the characteristic wave modes of solar wind turbulence in the vicinity of the shock observed by both spacecraft. We find that the observed ICME-driven shock is a fast, forward oblique shock with a more perpendicular shock angle at the Wind position. After the shock crossing, the magnetic field fluctuation power increases. Most of the magnetic field fluctuation power resides in the transverse fluctuations. In the vicinity of the shock, both spacecraft observe right-hand polarized waves in the spacecraft frame. The upstream wave signatures fall within a relatively broad and low-frequency band, which might be attributed to low-frequency MHD waves excited by the streaming particles. For the downstream magnetic wave activity, we find oblique kinetic Alfvén waves with frequencies near the proton cyclotron frequency in the spacecraft frame. The frequency of the downstream waves increases by a factor of ∼7–10 due to the shock compression and the Doppler effect.

*We acknowledge the partial support of the NSF EPSCoR RII-Track-1 Cooperative Agreement OIA-1655280 and a NASA award 80NSSC20K1783. The Solar Orbiter magnetometer was funded by the UK Space Agency (grant ST/T001062/1)

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Publication: Turbulence and wave transmission at an ICME-driven shock observed by the Solar Orbiter and Wind
L.-L. Zhao, G. P. Zank, J. S. He, D. Telloni, Q. Hu, G. Li, M. Nakanotani, L. Adhikari, E. K. J. Kilpua, T. S. Horbury, H. O'Brien, V. Evans, V. Angelini
A&A, Forthcoming article
Received: 29 January 2021 / Accepted: 30 April 2021
DOI: 10.1051/0004-6361/202140450

Presenters

  • Lingling Zhao

    • University of Alabama in Huntsville
    • The University of Alabama in Huntsville
    • Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899, USA
    • Center for Space Plasma and Aeronomic Research (CSPAR) University of Alabama in Huntsville Huntsville, AL 35805, USA

Authors

  • Lingling Zhao

    • University of Alabama in Huntsville
    • The University of Alabama in Huntsville
    • Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899, USA
    • Center for Space Plasma and Aeronomic Research (CSPAR) University of Alabama in Huntsville Huntsville, AL 35805, USA

  • Gary P Zank

    • University of Alabama in Huntsville
    • Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899, USA
    • University of Alabama-Huntsville

  • Jiansen He

    • Peking University

  • Danielle Telloni

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

  • Qiang Hu

    • The university of Alabama in Huntsville

  • Gang Li

    • The university of Alabama in Huntsville

  • Masaru Nakanotani

    • The university of Alabama in Huntsville
    • Center for Space Plasma and Aeronomic Research (CSPAR) University of Alabama in Huntsville Huntsville, AL 35805, USA

  • Laxman Adhikari

    • The University of Alabama in Huntsville
    • University of Alabama in Huntsville
    • The university of Alabama in Huntsville
    • Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899, USA
    • Center for Space Plasma and Aeronomic Research (CSPAR) University of Alabama in Huntsville Huntsville, AL 35805, USA

  • Emilia Kilpua

    • University of Helsinki

  • Tim Horbury

    • Imperial College London
    • Department of Physics, The Blackett Laboratory, Imperial College London, London, UK