Resolution No. 2 (2021): Polar Cap (PC) index

IAGA, noting

• that polar cap magnetic activity is not yet described by existing IAGA geomagnetic indices;

Considering

• that the Polar Cap (PC) index constitutes a quantitative estimate of geomagnetic activity at polar latitudes and serves as a proxy for energy that enters into the magnetosphere during solar wind-magnetosphere coupling;

Emphasising

• that the usefulness of such an index is dependent on having a continuous data series;

Recognising

• that the PC index is derived in partnership between the Arctic and Antarctic Research Institute (AARI, Russian Federation) and the National Space Institute, Technical University of Denmark (DTU, Denmark);

Recommends

• use of the PC index by the international scientific community, and

Urges

• that all possible efforts be made to maintain continuous operation of all geomagnetic observatories contributing to the PC index.

[Note 1: Renewal of Resolution No.4 (1997) after a long-term dispute about the method to derive the PC index has been settled in 2013]

[Note 2: Amendment of Resolution No. 3 (2013) for the purpose of clarification. The words “in its near real time and definitive forms” have been removed. “Note” has been renamed to “Note 1” and the words “in 2013” added to Note 1]