Analysis of the first four moderate geomagnetic storms of the year 2015

Abstract

This essay investigates of rst four moderate geomagnetic activities (04 January storm, 07 January storm, 17 February storm, and 24 February storm) of 2015 in the 24 th solar cycle. It tries to understand these storms with the aid of the zonal geomagnetic indices. It predicts the zonal geomagnetic indices (Dst, ap, AE) of the storms by an arti cial neural network model. The phenomena that occurred in January and February are discussed on the solar wind parameters (B z , E, P, N, v, T) and the zonal geomagnetic indices obtained from NASA. In the study, after glancing at the 2015-year general appearance, binary correlations of the variables are indicated by the covariance matrix, and the hierarchical cluster of the variables are presented by the dendrogram.The arti cial neural network model is governed by the physical principles in the paper. The model uses the solar wind parameters as inputs and the zonal geomagnetic indices as outputs. The causality principle forms the models by cause-effect association. Back propagation algorithm is speci ed as Levenberg-Marquardt (trainlm) and 35 neural numbers are utilized in the arti cial neural network. The neural network model predicts the Dst, ap, and AE indices of January and February geomagnetic storms with an accuracy that deserves discussion. Estimating the geomagnetic activities may support interplanetary works. value of 12.36 nPa and the proton density N hits its maximum value of 29.4 1/cm 3 . After two hours, on 07 January at 9:00 UT the B z magnetic eld decreases to its minimum value (-17.04 nT), the electric eld E ranges to its highest value of 8.16 mV/m, the AE index shows its maximum value of 1327 nT, and the ap ZG index hits its maximum value of 94 nT.