Indices of Global Geomagnetic Activity

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.

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

Nowcast Kp Index

Nowcast 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.

Kp index data from this website is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0)


Dr. Jürgen Matzka

Section 2.3: Geomagnetism

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Gebäude H 1, Raum 213
14823 Niemegk
Tel.: +49 331 33843 624-18