The dynamic regime of the ionospheric E-region as observed at Irkutsk

摘要

Presented are the results derived from analyzing the observations of horizontal ionospheric drifts at the ionospheric E-region heights. The observations were made during 1958-1982 using the method of spaced receivers at vertical-incidence radio soundings. The observational data were analyzed separately for the regular E-layer and for the sporadic Es-layer. The complex character of the dynamic regime in this region of space is emphasized. Inspection of the data suggests that the sporadic Es-features are fully involved in the drifts of regular layers. The difference of the horizontal drift parameters implies that for the regular E-layer the north-eastern directions occur by 0-15% more frequently when compared with the drifts of the sporadic Es-layer. It is pointed out that with increasing geomagnetic activity, there is an increase of the probability of the north-eastward transport. The mean value of the modulus of the drift velocity vector in different directions is 100-110 m/s. The azimuth of the drift velocity vector changes clockwise on a diurnal scale. In this case the prevailing drift directions differ both in seasons and in the dayside and nightside ionosphere.