OBSERVATION OF TOTAL ELECTRON-CONTENT, AMPLITUDE AND PHASE SCINTILLATIONS IN THE AURORAL IONOSPHERE

The connection between the spatial gradient of the equivalent vertical total electron content (N(tot)) of the ionosphere and scintillation p atches are examined. It is shown that in the evening hours under quiet geomagnetic conditions, a steplike gradient of N(tot) with latitude d evelops at the northern edge of the main ionospheric trough. Later in the evening, the above structure moves southward and the latitudinal g radient of N(tot) becomes very pronounced and around it a scintillatio n patch is formed. During magnetic disturbances, the monotonic sharp g radient of N(tot) is destroyed. A number of maxima of total electron c ontent which become collocated with many scintillation patches are for med. Further, under disturbed conditions, the power law index of both the amplitude and phase scintillation spectra shows a marked variation with latitude which may be quasi-periodic.