|An Index (PC) Aimed at Monitoring the (P)olar (C)ap for Magnetic Activity
|PC is an index for magnetic activity in the (P)olar (C)ap. It is based on data from
a single nearpole station, and aimed to monitor the polar cap magnetic activity generated
by such solar wind parameters as the southward component of the interplanetary magnetic
field (IMF), the azimuthal component of the IMF (By), and the solar wind velocity
v. The station Thule, located in the village Qaanaaq in Greenland at 86.5 degrees
geomagnetic invariant latitude, fulfills the requirement of being close to the magnetic
pole in the northern hemisphere. The station Vostok at 83.3 degrees does the same
in the southern hemisphere. The PC index is derived independently for these two stations.
The PC-index is based on an idea by Troshichev et al. (1979) and developed in papers
by Troshichev and Andrezem (1985), ennerstrom et al. (1991). Earlier data for 1975-1982
appear in Troshichev et al. (1991). The data from 1975 to the present are published
in Report UAG-103, available from the National Geophysical Data Center.