Regional properties of traveling ionospheric disturbances observed in Central China Original Research Article

The present work investigates the regional properties of medium scale traveling ionospheric disturbances (TIDs) in Central China. By statistically analyzing some 6-year data of an HF Doppler array, we obtain the preferred propagation directions, the scale distribution and the seasonal changes of the observed TIDs. The main results are: (1) Most of the observed TIDs propagate in northeastward and southeastward directions, and a few in southwestward direction; (2) Both the spatial and temporal scales of the northeastward TIDs are much smaller than those of the southeastward TIDs; (3) The northeastward TIDs like to appear in spring and summer, and the southeastward TIDs like to appear in autumn and winter. The origin of these regional properties is suggested to have relationship with certain kind of meteorology events.