ON THE GLOBAL AND REGIONAL BEHAVIOR OF THE MIDLATITUDE IONOSPHERE

Data from a chain of seven ionosondes in the range of 56-38-degrees-N and 1-38-degrees-E geographic coordinates were analysed to illustrate the global and regional behaviour of the mid-latitude F-region for som e selected geomagnetic storms that occurred during the solar cycle 21. It was found that there are different spatial scales in the response of the mid-latitude ionosphere to the disturbance in the magnetosphere -ionosphere-thermosphere system. The physical mechanisms and processes are discussed in relation to the relevance of various theories in the understanding of the dynamics of ionospheric storms.