  The source of diffuse aurora has been widely studied and linked to electron
cyclotron harmonic (ECH) and upper-band chorus (UBC) waves. It is known that
these waves scatter 100s of eV to 10s of keV electrons from the plasma sheet,
but the relative contribution of each wave type is still an open question. In
this paper, we report on an interesting and unusual auroral feature observed on
March 15, 2002. We believe that these observations could help further our
understanding of waves associated with diffuse aurora. This diffuse auroral
feature is characterized by four phases: (1) the initial phase exhibiting
regular diffuse aurora, (2) the brightening phase, where an east-west auroral
stripe rapidly brightens, (3) the eraser phase, where the stripe dims to below
its initial state, and (4) the recovery phase, where the diffuse aurora returns
to its original brightness. Using a superposed epoch analysis of 22 events, we
calculate the average recovery phase time to be 20 seconds, although this
varies widely between events. We hypothesize that the process responsible for
these auroral eraser events could be the result of chorus waves modulating
diffuse aurora.
