The long-term ionospheric characteristics over Haikou

There are important effects on the electron equipments for the variations of ionosphere, such as it can induce shortwave communications quality decline even interrupted, navigation signal scintillation and error increase, space aerocraft orbit changes, hardware charging up and proton events etc. In a word, studying ionospheric characteristics is indispensable to study the ionospheric effects on electron equipments. Based on Haikou ionospheric vertical sounders station nearly fifty years data, the ionospheric daily variations, seasonal variations and long trend variations over Haikou area were studied and some meaningful conclusions were gained.