What can Hall-MHD simulations tell us about the transition region in the solar wind proton density spectrum?
- 1Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Prague, Czechia (victor@aurora.troja.mff.cuni.cz)
- 2LPP, Ecole Polytechnique, Palaiseau, France
- 3Dipartimento di Fisica e Astronomia, Universit ́a di Firenze, Firenze, Italia
Similarly to the power density spectrum of magnetic field fluctuations in the solar wind, the spectrum of density fluctuations also shows multiple spectral slopes. Both of them present a spectral index varying between –3/2 and –5/3 in the inertial range and close to –2.8 between the proton and electron gyrofrequencies.
Despite these similarities, the spectrum of density fluctuations has a significant difference with respect to the magnetic and velocity fluctuations spectra: it shows a transition region between the inertial and the kinetic ranges with spectral index typically around –1.
We have combined the results of compressible Hall-MHD numerical simulations and measurements of the BMSW instrument onboard Spektr-R satellite to study the possible causes of the flattening in the density spectrum. Both numerical and experimental approaches point towards an important role played by Kinetic Alfvén Waves.
How to cite: Montagud-Camps, V., Němec, F., Šafránková, J., Němeček, Z., Grappin, R., Verdini, A., and Pitňa, A.: What can Hall-MHD simulations tell us about the transition region in the solar wind proton density spectrum?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2440, https://doi.org/10.5194/egusphere-egu2020-2440, 2020.
