Multipoint measurements of large DC electric fields and shears in the auroral zone

We present electric field and electron data from the Auroral Turbulence II (AT2) sounding rocket mission. This three pay load rocket flew through several discrete night side auroral arc structures. The pay loads traversed a large, stable arc structure containing, near its poleward edge, at least 400 mV/m of DC electric field, together with broadband waves in the electric field at frequencies from DC up to 100 Hz. Multipoint measurements allow us to determine the size of this region and to observe that it is characterized by two distinct variations: a region of spatial shear approximately 1 km in extent across the arc, immediately followed by a region of temporal change in electric field, nearly 6 km in extent. The observed broadband waves do not show a preference for the spatial shear region over the time varying region.