G. Provan et al., CUTLASS FINLAND RADAR OBSERVATIONS OF THE IONOSPHERIC SIGNATURES OF FLUX-TRANSFER EVENTS AND THE RESULTING PLASMA FLOWS, Annales geophysicae, 16(11), 1998, pp. 1411-1422
The CUTLASS Finland radar has been run in a two-beam special scan mode
, which offered excellent temporal and spatial information on the flow
s in the high-latitude ionosphere. A detailed study of one day of this
data revealed a convection reversal boundary (CRB) in the CUTLASS fie
ld of view (f.o.v) on the dayside, the direction of plasma flow either
side of the boundary being typical of a dawn-cell convection pattern.
Poleward of the CRB a number of pulsed transients are observed, seemi
ngly moving away from the radar. These transients are identified here
as the ionospheric signature of flux transfer events (FTEs). Equatorwa
rd of the CRB continuous backscatter was observed, believed to be due
to the return flow on closed field lines. The two-beam scan offered a
new and innovative opportunity to determine the size and velocity of t
he ionospheric signatures associated with flux transfer events and the
related plasma flow pattern. The transient signature was found to hav
e an azimuthal extent of 1900 +/- 900 km and an poleward extent of sim
ilar to 250 km. The motion of the transient features was in a predomin
antly westward azimuthal direction, at a velocity of 7.5 +/- 3 km.