Clyde River (CLY) SuperDARN radar velocities reflecting plasma flows in the ionosphere are consistent with measurements by the incoherent scatter radar RISR. While agreement is good in the range of RISR velocity magnitudes of 0–700 m s⁻¹, CLY velocities become progressively smaller at faster flows. In one example of strong disagreements between the instruments, by 200 m s⁻¹, the radars monitored strongly sheared flows. Validation of the CLY radar confirms the reliability of SuperDARN operation.

The asymmetries between the leading and trailing edges of large-scale plasma density structures in the ionosphere are examined using a general formalism for the gradient-drift instability for arbitrary altitude and propagation direction. The asymmetry changes dramatically with propagation direction and is most likely to be observed by a ground-based radar when the radar’s boresight is parallel to the structure’s elongation direction and perpendicular to its direction of motion.

Convection reversal boundary (CRB) is a special characteristic of plasma flow patterns in the high-latitude ionosphere. It is typically a border line between regions with closed and open Earth’s magnetic field lines. This paper investigates seasonal and solar cycle trends in the CRB location. We use an extensive Super Dual Auroral Radar Network data base for 19 years of operation and apply a non-standard approach of making monthly averaged convection maps.