Magnetic Helicity Associated with the Proton Temperature Anisotropy Instabilities in the Presence of an Imbalanced Solar Wind Turbulence

Abstract Some of the most common processes in solar wind, such as turbulence and wave generation by instabilities, are associated with spectral magnetic helicity. Therefore, helicity is a convenient tool to investigate these processes. We use three-dimensional nonlinear kinetic simulations particle ions fluid electrons analyze produced proton temperature anisotropy instabilities coexisting an ambient turbulence. The symmetry unstable system violated alpha-particle streaming respect protons along mean field. At same time, turbulent fluctuations also imbalanced nonzero cross-helicity. show that phase instability resulting structure different from prediction linear theory. In particular, it contains sign reversals multiple domains generates its own signature, which extends over wide range angles around direction perpendicular field, can have or opposite instability. These findings consistent observed spectra wind.