EGU23-6253, updated on 08 Jan 2024
https://doi.org/10.5194/egusphere-egu23-6253
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Turbulent energy transfer and dissipation in the terrestrial magnetosheath

Zoltan Vörös1,2, Owen Wyn Roberts1, Luca Sorriso-Valvo3,4, Emiliya Yordanova4, Yasuhito Narita1, Rumi Nakamura1, and Ferdinand Plaschke5
Zoltan Vörös et al.
  • 1Space Research Institute, Austrian Academy of Sciences, Graz, Austria
  • 2Institute of Earth's Physics and Space Science, ELRN, Sopron, Hungary
  • 3CNR/ISTP – Istituto per la Scienza e Tecnologia dei Plasmi, Via Amendola 122/D, 70126 Bari, Italy
  • 4Swedish Institute of Space Physics (IRF), Ångström Laboratory, Lägerhyddsvägen 1, SE-751 21 Uppsala, Sweden
  • 5Institute of Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Germany

The terrestrial magnetosheath (MS) represents a turbulent, high-beta, compressional, sporadically Alfvenic environment which contains the shocked solar wind (SW) magnetized plasma permeated with waves, instabilities and structures of various origins. In the processes of interaction of the structured SW with the shock and the MS, the electromagnetic, kinetic and thermal energies are transported between locations,  transferred between scales, conversed between each other and finally dissipated. Similarly to the SW case the energy transfer in MS is expected to be manifested in typical scalings seen in power spectral densities of various field and plasma parameters  over the fluid (inertial-range) and kinetic ion-electron scales. However, near the sub-solar dayside MS the inertial-range turbulent cascade is usually absent, while the kinetic range scaling roughly remains the same as in the SW. Observations of short magnetic correlation lengths near the sub-solar MS also confirm the absence of large-scale magnetic fluctuations which could populate the inertial-range of scales. Without the inertial range energy cascade the kinetic range turbulence should exhibit a fast decay downstream of the shock, but it is not observed. We argue that to understand the spectral scalings in the MS the whole energy budget has to be considered including possible nonlocal energy transfer terms. By using MMS data in the MS we show that, when the inertial range is present, the turbulent energy dissipation rate can be estimated by the energy transfer rate from both the Yaglom law and from the pressure-strain interaction term. When the inertial range is absent and the Yaglom law cannot be used,  the dissipation rate can still be estimated by using the pressure-strain term.

How to cite: Vörös, Z., Roberts, O. W., Sorriso-Valvo, L., Yordanova, E., Narita, Y., Nakamura, R., and Plaschke, F.: Turbulent energy transfer and dissipation in the terrestrial magnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6253, https://doi.org/10.5194/egusphere-egu23-6253, 2023.