Öz
This essay involves mathematical analyzes of 21 July 21, 2017, geomagnetic storm in the 24th solar cycle. It focuses on solar wind parameters (Bz, E, P, N, v, T), zonal geomagnetic indices (Dst, ap, AE, Kp) obtained from NASA and discusses the July storm by strictly obeying the cause-effect relationship. The paper examines the phenomenon carefully and tries to reveal properties of the storm with the models governing by the causality principle. In this study, values interval and deviations of the variables are defined via descriptive analysis, binary relationships of the data are displayed with the covariance matrix and the cluster of the data are introduced by the dendrogram. Factor analysis is conducted with the help of normal distributions of the data and the phenomenon is tried to discuss with linear and nonlinear models. The study, without detachment from the context of the discussion, also detects anomalies of total electron content (TEC) data obtained from CODE (GIM).