Analysis of Y -component of Geomagnetic Field and SYM-H Index Using Wavelet Multiresolution Analysis

Electrodynamical coupling between the solar wind’s plasma and the Earth’s magnetosphere creates geomagnetic disturbances recorded on the ground. This work analyzes the Y -component of the geomagnetic field during two geomagnetic storms and compares it to the solar quiet days. The magnetogram data recorded on low latitude stations are used for the study. We investigated the correlation of the Y -component with geomagnetic index SYM-H using wavelet multiresolution analysis. We have used solar wind velocity, pressure, and interplanetary magnetic fields ( By and Bz ) to know the interplanetary structure for the selected duration. We found a positive correlation between Y -component and the SYM-H index for both events. The magnitude of the Y -component was significantly reduced during the main phase in comparison to the quiet days. Further, variation of solar wind parameters indicated geomagnetic storms are guided by the prolonged southward IMF- Bz component and highly fluctuated IMF- By component. This work connects the interplanetary plasma parameters to the storm-time geomagnetic variations.