New detail on auroral processes

Abstract

High‐resolution imaging from spacecraft is revealing new detail on structures in bright, dynamic auroras. In the auroral regions where particles are accelerated to high energies, dynamic structures evolve on time scales of seconds or less, although the processes that drive particle acceleration and transfer of energy to small scales are not fully understood. Chaston et al. show how new spaceborne auroral imagery combined with simultaneous particle measurements can help improve understanding of the physical processes involved in the aurora. In particular, they show how magnetic reconnection (in which magnetic field lines break and reconnect, releasing energy), tearing, and sheared flows can transfer energy from larger to smaller scales and help form the auroral structures observed. (Geophysical Research Letters, doi:10.1029/2011GL049185, 2011)