Relationship between solar wind parameters and magnetic activity in the near-pole region: Application to space weather forecasting

Abstract

We studied the relationship between solar wind and geomagnetic disturbances in the near-pole region using the polar cap index ( PC) at Thule and WIND satellite data. The results of the analyses showed that the PC index is saturated when the merging electric field ( E m ) is high (more than 5 mV/m) and that the PC index is enhanced by the effect of the DP 1 current system. Further, the E m and the PC index show a good correlation with energy injection rate Q. This result suggests that ring current development can be estimated from the PC index as well as from the E m . Therefore, the real-time PC index is useful for monitoring the magnetospheric electric field and nowcasting and forecasting geomagnetic storms.