Statistical study of electron density turbulence and ion-cyclotron waves in the inner heliosphere: Solar Orbiter observations

0550196 - ÚFA 2022 RIV FR eng J - Journal Article
Carbone, F. - Sorriso-Valvo, L. - Khotyaintsev, Y. V. - Steinvall, K. - Vecchio, A. - Telloni, D. - Yordanova, E. - Graham, D. B. - Edberg, N.J.T. - Eriksson, A.I. - Johansson, E.P.G. - Vásconez, L. - Maksimovic, M. - Bruno, R. - D'Amicis, R. - Bale, S. D. - Chust, T. - Krasnoselskikh, V. - Kretzschmar, M. - Lorfèvre, E. - Plettemeier, D. - Souček, Jan - Steller, M. - Štverák, Štěpán - Trávníček, Pavel - Vaivads, A. - Horbury, T.S. - O'Brien, H. - Angelini, V. - Evans, V.
Statistical study of electron density turbulence and ion-cyclotron waves in the inner heliosphere: Solar Orbiter observations.
Astronomy & Astrophysics. Roč. 656, Dec 14 (2021), č. článku A16. ISSN 0004-6361. E-ISSN 1432-0746
Institutional support: RVO:68378289
Keywords : solar wind * turbulence * waves * plasmas
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 6.240, year: 2021
Method of publishing: Open access
https://arxiv.org/pdf/2105.07790.pdf

Context. The recently released spacecraft potential measured by the RPW instrument on board Solar Orbiter has been used to estimate the solar wind electron density in the inner heliosphere.
Aims. The measurement of the solar wind’s electron density, taken in June 2020, has been analysed to obtain a thorough characterization of the turbulence and intermittency properties of the fluctuations. Magnetic field data have been used to describe the presence of ion-scale waves.
Methods. To study and quantify the properties of turbulence, we extracted selected intervals. We used empirical mode decomposition to obtain the generalized marginal Hilbert spectrum, equivalent to the structure functions analysis, which additionally reduced issues typical of non-stationary, short time series. The presence of waves was quantitatively determined by introducing a parameter describing the time-dependent, frequency-filtered wave power.
Results. A well-defined inertial range with power-law scalng was found almost everywhere in the sample studied. However, the Kolmogorov scaling and the typical intermittency effects are only present in fraction of the samples. Other intervals have shallower spectra and more irregular intermittency, which are not described by models of turbulence. These are observed predominantly during intervals of enhanced ion frequency wave activity. Comparisons with compressible magnetic field intermittency (from the MAG instrument) and with an estimate of the solar wind velocity (using electric and magnetic field) are also provided to give general context and help determine the cause of these anomalous fluctuations.
Permanent Link: http://hdl.handle.net/11104/0326009