Latitudinal Variation of H⁺ Flow Velocity from Alouette-2 Topside Sounder Profiles

190-193Electron density profiles from the Alouette-2 topside sounder are used to estimate the H+ flow velocity at latitudes above 50° geomagnetic. The flow velocity increases with latitude resulting in a clear peak at the latitude of the electron density trough beyond which the velocity starts decreasing. A detailed examination of the flow velocity, calculated from the data covering the period from Jan. 1966 to Dec. 1967, shows significant seasonal changes, with velocities larger in winter than in summer. Also the daytime values of the flow velocity are found to be smaller than the nighttime values. Effects of magnetic storms of the H+ flow velocity are also examined