Indices of Global Geomagnetic Activity

This service contributes to the International Service of Geomagnetic Indices (ISGI) of the IAGA.

The planetary three-hour-range Kp index was introduced by J. Bartels in 1949 and is derived from the standardized K index (Ks) of 13 magnetic observatories. It is designed to measure solar particle radiation by its magnetic effects.

The geomagnetic ap, Ap, Cp and C9 and the classification of international Q-days and D-days are derived from the Kp index.

Quicklook Kp Index

Quicklook Kp index, shown daily in a bar plot with an overview of the last six days.

Most Recent Definitive Indices

Planetary magnetic three-hour-range indices, shown in old style musical diagram.


Profile photo of  Dr. Jürgen Matzka

Dr. Jürgen Matzka
Earth's Magnetic Field

Lindenstr. 7
Building H 1, room 101
14823 Niemegk
tel. +49 33843 624-18


Profile photo of  Prof. Dr. Claudia Stolle

Prof. Dr. Claudia Stolle
Earth's Magnetic Field

Behlertstraße 3a
Building K 3, room 012
14467 Potsdam
tel. +49 331 288-1230

In cooperation with:

International Association of Geomagnetism and Aeronomy
Service International des Indices Geomagnetiques