Spectrum of kinetic plasma turbulence at 0.3-0.9 AU from the Sun
- 1LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, 5 place Jules Janssen, 92195 Meudon, France (olga.alexandrova@obspm.fr)
- 2National Institute for Astrophysics-Institute for Space Astrophysics and Planetology, Via del Fosso del Cavaliere 100, I-00133 Roma, Italy
- 3Astronomical Institute, CAS, Bocni II/1401, Prague CZ-14100, Czech Republic
- 4GFZ German Research Centre for Geosciences, University of Potsdam, Germany
We investigate the spectral properties of the turbulence in the solar wind which is a weakly collisional astrophysical plasma, accessible by in-situ observations. Using the Helios search coil magnetometer measurements in the fast solar wind, in the inner heliosphere, we focus on properties of the turbulent magnetic fluctuations at scales smaller than the ion characteristic scales, the so-called kinetic plasma turbulence. At such small scales, we show that the magnetic power spectra between 0.3 and 0.9 AU from the Sun have a generic shape ~f-8/3exp(-f/fd) where the dissipation frequency fd is correlated with the Doppler shifted frequency fρe of the electron Larmor radius. This behavior is statistically significant: all the observed kinetic spectra are well described by this model, with fd=fρe/1.8. These results provide important constraints on the dissipation mechanism in nearly collisionless space plasmas.
How to cite: Alexandrova, O., Krishna Jagarlamudi, V., Hellinger, P., Maksimovic, M., Shprits, Y., and Mangeney, A.: Spectrum of kinetic plasma turbulence at 0.3-0.9 AU from the Sun, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12072, https://doi.org/10.5194/egusphere-egu21-12072, 2021.
