Structure and dynamics of polar cap F-layer patches

Coordinated measurements of F-region plasma patches were conducted on 3 and 4 February 1984 from Thule and Sondrestrom, Greenland. Optical, ionosonde, amplitude scintillation, Total Electron Content (TEC), and incoherent scatter radar measurements were combined to reveal several new aspects of the structure and transport of these localized regions of enhanced F-region ionization. These patches were directly tracked for the first time flowing anti-sunward from the center of the polar cap to the poleward edge of of the auroral oval. Amplitude scintillation caused by irregularities within these structured patches showed a systematic increase on the trailing edge of the patches consistent with an E X B instability mechanism. Equally important, significant scintillation was also observed on the loading edge and throughout the patch, requiring another instability mechanism to produce irregularities throughout the interior of the patch. Keywords: F region; Polar cap plasma; Polar cap ionospheric irregularities.