Wavevector anisotropy of ion-scale plasma turbulence is studied at various values of ion beta.Two complementary methods are used.One is multi-point measurements of magnetic field in the near-Earth solar wind as provided by the Cluster spacecraft mission, and the other is hybrid numerical simulation of two-dimensional lithium batteries plasma turbulence.Both methods demonstrate that the wavevector anisotropy is reduced with increasing values of ion beta.
Furthermore, the numerical simulation study shows the existence of a scaling law between ion beta and the wavevector anisotropy of the fluctuating magnetic field that is controlled by the thermal or hybrid particle-in-cell simulation noise.Likewise, there is weak evidence that the power-law scaling can be extended to Pendant the turbulent fluctuating cascade.This fact can be used to construct a diagnostic tool to determine or to constrain ion beta using multi-point magnetic field measurements in space.