The effect on sporadic-E region of quasi-biennial oscillaton occured at equatorial stratosphere

In this study, it is statistically investigated whether there is a relationship between critical frequency (foEs) of the sporadic-E that seen occasionally on E-region of ionosphere and the quasi-biennial oscillation (QBO) that flow at the east-west direction in the equatorial stratosphere or not. Multiple regression model as a statistical tool was used to determine the relationship between variables. In this model, the stationarity of the variables (foEs and QBO) was firstly analyzed for each station (Casos Island, Gibilmanna, Niue Island, and Tahiti). Then, co-integration test was made to determine the existence of a long-term relationship between QBO and foEs. After determining the presence of a long-term relationship between the variables, the magnitude of the relationship between variables was determined by using the multiple regression model. It is concluded that the variations in foEs was explainable with QBO measured at 10 hPa altitude at the rate of 69%, 94%, 79% and 58% for Casos Island, Gibilmanna, Niue Island and Tahiti stations, respectively. It is observed that the variations in foEs was explainable with QBO measured at 70 hPa altitude at the rate of 66%, 69%, 53% and 47% for Casos Island, Gibilmanna, Niue Island and Tahiti stations, respectively. Key Words: Multiple Regression Model; Equatorial Region; Sporadic-E; QBO