Turbulent energy cascade in the inner heliosphere: a universal process underlying different turbulent patterns - Archive ouverte HAL Accéder directement au contenu
Poster De Conférence Année : 2017

Turbulent energy cascade in the inner heliosphere: a universal process underlying different turbulent patterns

Andrea Verdini
  • Fonction : Auteur
Roland Grappin
Victor Montagud-Camps

Résumé

Direct measurements of the rate of turbulent energy cascade at 1 AU via structure functions (e.g., Starwarz et al 2009) indicate that the cascade rate is comparable to the level required to obtain the observed slow radial decrease of proton temperature observed in the inner heliosphere (Totten et al 1995). This is in contrast with the diversity of turbulent anisotropy (Dasso et al 2005, Verdini Grappin 2015) observed, as well as the systematicchange in spectral slope when passing from slow, cold flows to fast, hot flows.We want here to isolate initial conditions around 0.2 AU that can show at the same time the observed universal temperature gradient and the variety of turbulent patterns found in fast and slow winds. Direct numerical simulations of turbulent evolution including solar wind expansion are done allowing to measure directly the turbulent heating between 0.2 and 1 AU. When starting at 0.2 AU with large scale excitation of wavenumbers mainly perpendicular to the mean field, that is, corresponding to the 2D configuration characteristic of slow winds (Dasso et al 2005), we find a radial proton temperature gradient close to the 1/R profile observed, when adopting reasonable values of the Mach number and expansion rate. The fast/hot wind case is discussed.
Fichier non déposé

Dates et versions

hal-02861318 , version 1 (08-06-2020)

Identifiants

  • HAL Id : hal-02861318 , version 1

Citer

Andrea Verdini, Roland Grappin, Victor Montagud-Camps. Turbulent energy cascade in the inner heliosphere: a universal process underlying different turbulent patterns. American Geophysical Union, Fall Meeting 2017, Dec 2017, New Orleans, Louisiane, United States. 11, pp.SH11B-2455, 2017. ⟨hal-02861318⟩
14 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More