Satellite beacon observations carried out in Cuba during solar cycle 21 and its theoretical interpretation with help of a numerical model

Ionospheric electron content measurements obtained in the American sector (Havana, Cuba) during the solar cycle 21 are presented. In combination with vertical sounding data (from San Jose de Las Lajas near Havana) these observations are analyzed with regard to solar activity dependence of the interhemispheric ionospheric coupling processes. The data indicate an obvious nighttime winter anomaly effect during low solar activity conditions which disappears with increasing solar activity. A physical-numerical model of the coupled system L = 1.5 in the American sector is applied to low and higher level of solar activity under quiet geomagnetic conditions. These calculations are compared with the observations.