Small-scale Structure and Variability in Mid-Latitude Ionospheric Plasma Convection

English Abstract:

The plasma of the mid-latitude ionosphere is perturbed by strong electric fields that extend equatorward of the usual auroral zone during disturbed periods. The resulting plasma density irregularities and plasma convection are observed with the radars of the new mid-latitude SuperDARN chain. In addition, the radars regularly observe backscatter from the ionosphere on the nightside during quiet times at subauroral latitudes; these velocities measure only tens of meters per second and appear to be well organized. The fields of view of the mid-latitude radars overlap extensively forming common volumes in the North American sector that make it possible to map the structure and variability of the convection with high confidence at the smallest resolutions afforded by the radar measurements, namely, tens of seconds in time and tens of kilometers in distance. We describe early results from a study of the characteristic scales of velocity variation in mid-latitude plasma convection and the connection to effects in Magnetosphere-Ionosphere-Thermosphere coupling.