English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Understanding the nature of the turbulent fluctuations below the iongyroradius in solar-wind turbulence is a great challenge. Recent studies havebeen mostly in favor of kinetic Alfv\'en wave (KAW) type of fluctuations, butother kinds of fluctuations with characteristics typical of magnetosonic,whistler and ion Bernstein modes, could also play a role depending on theplasma parameters. Here we investigate the properties of the sub-proton-scalecascade with high-resolution hybrid-kinetic simulations of freely-decayingturbulence in 3D3V phase space, including electron inertia effects. Two protonplasma beta are explored: the "intermediate" $\beta_p=1$ and "low"$\beta_p=0.2$ regimes, both typically observed in solar wind and corona. Themagnetic energy spectum exhibits $k_\perp^{-8/3}$ and $k_\|^{-7/2}$ power lawsat $\beta_p=1$, while they are slightly steeper at $\beta_p=0.2$. Nevertheless,both regimes develop a spectral anisotropy consistent with $k_\|\simk_\perp^{2/3}$ at $k_\perp\rho_p>1$, and pronounced small-scale intermittency.In this context, we find that the kinetic-scale cascade is dominated byKAW-like fluctuations at $\beta_p=1$, whereas the low-$\beta$ case presents amore complex scenario suggesting the simultaneous presence of different typesof fluctuations. In both regimes, however, a non-negligible role of ionBernstein type of fluctuations at the smallest scales seems to emerge.

Kinetic cascade in solar-wind turbulence: 3D3V hybrid-kinetic simulations with electron inertia