PCN index

The Polar Cap index (abbreviation PC index) monitors geomagnetic activity on the Polar Caps. This IAGA-endorsed index consists of two parts: PCN describes activity in the Northern Polar Cap and is determined from magnetic data taken at the geomagnetic observatory Qaanaaq (Thule) in Greenland (+85 degree magnetic latitude) under the responsibility of DTU Space. PCS monitors activity in the Southern Polar Cap and is determined by Arctic and Antarctic Research Institute (AARI).

The idea behind these indices is to estimate the intensity of anti-sunward plasma convection in the polar caps. This convection is associated with electric Hall currents and consequent magnetic field variations perpendicular to the antisunward plasma flow (and related Hall current) which can be monitored at the Qaanaaq and Vostok magnetic observatories.

PC aims at monitoring the energy input from solar wind to the magnetosphere (loading activity). The index is constructed in such a way that it has a linear relationship with the merging Electric Field at the magnetopause; consequently PC is given in units of mV/m as for the electric field.

In August 2013, the International Association of Geomagnetism and Aeronomy (IAGA) endorsed the PC index. The endorsed PC index is accessible at pcindex.org, at the International Service of Geomagnetic Indices (ISGI) or through WDC for geomagnetism Copenhagen's FTP .

Data and plots


Software and scripts

Creative Commons licens
PCN index by DTU Space is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) . Citation
World Data Center For Geomagnetism, Copenhagen. (2019). The Polar Cap North (PCN) index (definitive) [Data set]. DTU Space, Geomagnetism. https://doi.org/10.11581/DTU:00000057