Analysis of Magnetic Fields in Inertial Alfvén Wave Collisions

Turbulence in astrophysical and space plasmas is dominated by the nonlinear interaction of counter propagating Alfvén waves. Most Alfvén wave turbulence theories have been based on ideal plasma models for Alfvén waves at large scales. However, in the inertial Alfvén wave regime, relevant to magnetospheric plasmas, how the turbulent nonlinear interactions are modified by the dispersive nature of the waves remains to be explored. Here, we present the first laboratory evidence of the nonlinear interaction in the inertial regime. A comparison is made with the theory for MHD Alfvén waves.