THE USE OF HORIZONTAL GEOMAGNETIC FIELD COMPONENTS FOR ESTIMATION OF GEOMAGNETICALLY INDUCED CURRENT OVER TURKEY DURING SPACE WEATHER EVENTS
Turkish Journal of Engineering (TUJE)
In this study, the time derivatives of the horizontal geomagnetic field components were computed to estimate the geomagnetically induced current (GIC) over Turkey during space weather events and the results were compared with the geomagnetic activity indices. The interplanetary magnetic field (IMF) index, disturbance storm time (Dst) index, global geomagnetic activity indices (ap and Kp) were used as indicator of space weather events. The changes because of solar flares and coronal mass
... oronal mass ejections in the space environment between the Sun and Earth are defined as space weather events. Such events' effects on the Earth's magnetosphere are called geomagnetic storms. In this study, two different space weather events that occurred on 20-26 June 2015 and 06-10 September 2017 are analyzed. The data of the horizontal magnetic field components used in the analysis are obtained from İznik magnetic observatory (40.5 ⸰ N, 29.7 ⸰ E). During space weather event on 20-26 June 2015, the maximum (max.) value of time derivative of (dX/dt and dH/dt) X and H horizontal magnetic field components were calculated as 72,22 nT/min. and 74,40 nT/min., respectively, while during space weather event on 06-10 September 2017, the max. value of the time derivative of the X and H horizontal magnetic field components are calculated and the results are 36,90 nT/min. and 38,12 nT/min., respectively. Also, it was observed that the strength of the local geomagnetic disturbance and amplitude of dX/dt and dH/dt at the observatory station depend strongly on the characteristics of geomagnetic activity indices during the space weather events. The southward IMF Bz component induces larger amplitude of dX/dt and dH/dt. The results indicate that the possibility of GIC occurrence over Turkey is quite high. Therefore, we strongly believe that further research and experiment on GIC for Turkey is important.