First observations of the temporal/spatial variation of the sub‐auroral polarization stream from the SuperDARN Wallops HF radar

[1] In this letter we present the first two-dimensional observations of sub-auroral ion drift (SAID) variability within the sub-auroral polarization stream (SAPS) using a new mid-latitude SuperDARN radar located at Wallops Island, VA. The radar data are complemented with observations from the DMSP F15, TIMED, and NOAA-18 spacecraft to confirm that a backscatter feature observed at the equatorward edge of the auroral oval is a manifestation of SAPS/SAID. During a several hour long period on August 6, 2005, the velocity data indicate that significant changes in the SAPS flow occurred on time scales of a few minutes. The Wallops HF radar observations demonstrate that the SAPS phenomenon is a source of small-scale irregularities extending over many hours of MLT and that the electric fields associated with SAID in particular are highly variable.