Cross-field transport due to low-frequency oscillations in the auroral region: A three-dimensional simulation

We have simulated the plasma transport processes in the nightside auroral region using our three‐dimensional (3‐D), multimoment, multifluid model. The model solves the continuity and momentum equations from 1500 km to 10 RE and allows self‐consistent treatment of the cross‐field transport. It has been shown that the low‐frequency D'Angelo instability, driven by the transverse inhomogeneity in the magnetic‐field‐aligned ion flow, was excited for the typical parameters in the auroral region. The instability generates cross‐field transport, which significantly modifies the field‐aligned flow. The effects of cross‐field transport are discussed. In the nonlinear stage of the instability, V‐shaped potential structures with magnitudes ∼1 kV are formed. The simulation provides insight into the dynamical evolution of the D'Angelo instability in the ionosphere‐magnetosphere coupling region, its effects on plasma transport processes, and formation of 3‐D potential structures.