SOME BEHAVIOURS OF IONOSPHERIC VARIATIONS OVER CHINA REGION

The paper reviews the relevant materials to characterize the main features of ionospheric properties over the china region through the important parameters of foF2 and TEC as well as some spread-F and sporadic-E phenomena..It is found that the major characteristics of the average and disturbed behaviours of the ionosphere are common with those observed at low and middle latitudes in other longitudinal sectors. It is also emphasized that some distinct behaviours in seasonal and diurnal variations of foF2 and TEC values are observed at different latitude stations in China and they may be caused by different ionospheric and dynamic effects including a strong equatorial fountain effect at southern stations and possibly large effect of middle atmosphere circulations at some northern stations.