Plasma convection at high latitudes using the EISCAT VHF and ESR incoherent scatter radars

The recent availability of substantial data sets taken by the ELSCAT Svalba rd Radar allows several important tests to be made on the determination of convection patterns from incoherent scatter radar results. During one 30-h period, the Svalbard Radar made 15 min scans combining local held aligned o bservations with two, low elevation positions selected to intersect the two beams of the Common Programme Four experiment being simultaneously conduct ed by the EISCAT VHF radar at Tromso. The common volume results from the tw o radars are compared. The plasma convection velocities determined independ ently by the two radars are shown to agree very closely and the combined th ree-dimensional velocity data used to test the common assumption of negligi ble field-aligned flow in this regime.