Quantification of the Cross-helicity Turbulent Cascade in Compressible MHD Simulations

Abstract In plasma turbulence, energy and cross helicity are transferred across scales at a constant rate as consequence of nonlinear interactions. incompressible magnetohydrodynamics (MHD), the cascade both quantities can be computed by means temporal evolution second-order structure functions, known Karman–Howarth–Monin (KHM) equations. present work, we derive KHM equation to compute in compressible MHD. Using three-dimensional direct numerical simulations, validate use it measure cross-helicity turbulence properties. Our results show slower development with respect one presence inverse cascades large when strong mean field. We propose relation these phenomena longer duration geomagnetic storms after arrival solar winds observation patchy inertial ranges displaying positive negative rates for certain wind intervals.