The turbulent Alfvenic aurora

It is demonstrated from observations that the Alfvenic aurora may be powered by a turbulent cascade transverse to the geomagnetic field from large MHD scales to small Alfven wave scales of several electron skin depths and less. We show that the energy transport through the cascade is sufficient to drive the observed acceleration of electrons from near-Earth space to form the aurora. We find that regions of Alfven wave dissipation, and particle acceleration, are localized or intermittent and embedded within a near-homogeneous background of large-scale MHD structures.