Quasi-real time geomagnetic data transfer from near northern magnetic pole region

摘要

It is well known that the magnetic field variations in the near geomagnetic-pole region can be used as an index of magnetospheric convection driven by solar wind-magnetos-phere coupling (PC index). Northern PC index (PCN) is derived from Qaanaaq (formally, Thule). Unfortunately, PCN is not produced in near-real time. To monitor the current condition of magnetospheric convection, it is necessary to collect geomagnetic field data in the near-geomagnetic pole region and to produce PCN-like index from those data. We have developed the system for collecting magnetic field data from Eureka, which is located in the northern near-pole region and transferring the data from Eureka to CRL in near real-time. Our system was installed at Eureka and has been operated since summer of 1999. Before producing PCN-like index from Eureka, we have compared geomagnetic field variations at Eureka and those at Qaanaaq. From the results of our data analysis, we have confirmed that PCN-like index can be derived from Eureka except for the period of low solar zenith angle (SZA < 70 deg.).