Planetary index of geomagnetic activity

Aurora borealis Kangerlussuaq, Greenland. Photo: Jürgen Matzka
Nowcast Kp index: Example of a particularly strong Kp index from 8 September 2017.

The Kp Index is one of the internationally most renowned geomagnetic indices. The German Research Centre for Geosciences GFZ has been providing this complex data service since 1997. It is based on data from 13 geomagnetic observatories. Scientists worldwide use the Kp Index for their research and data products. It is valuable for space climate studies, for the analysis of space weather, it is applied in empirical and physics-based models for aerospace activities or in models of the Earth's magnetic field. Currently, an average of more than 1000 publications per year − mostly ionospheric and magnetospheric studies – profit from it.

The global Kp index is a measure of irregular natural geomagnetic disturbances caused by the solar wind. Thus, the index also indicates geomagnetic storms caused by very strong solar flares, which can have far-reaching consequences on our electrical systems.

Julius Bartels first introduced the 3-hour geomagnetic Kp index in 1949. The Kp index is calculated from the K indices of 13 geomagnetic observatories, all of which are located outside the auroral zone. In Germany, for example, in Wingst, where observations have been taking place since 1938, and in Niemegk. Other European observatories are located in Sweden, Denmark, England and Scotland.

New publication on the Kp Index and DOI allocation

The GFZ data product has recently been assigned a DOI, the Digital Object Identifier 10.5880/Kp.0001 by GFZ Data Services. This gives the digital object a unique and permanently available access. In future, this will also provide a more precise overview of how often the GFZ's freely available data product is actually used.

Furthermore, the first comprehensive description of the Kp index since 1996 was recently published. The article "The geomagnetic Kp index and derived indices of geomagnetic activity" was published in the American scientific journal Space Weather. It was prepared under the leadership of Dr. Jürgen Matzka  and Prof. Claudia Stolle , who conduct research in the Geomagnetism Section at the GFZ. The publication displays the latest developments such as the real-time Kp and describes improvements that have been in effect since August 2020. The real-time Kp is now used by many institutions, including the European Space Agency (ESA) or the National Aeronautics and Space Administration (NASA).

  • Link to the publication in Space Weather (AGU Journal)
  • Link to the data publication

Scientific contact:

Dr. Jürgen Matzka 
Section 2.3 Geomagnetism
Helmholtz Centre Potsdam
German Research Centre for Geoscience GFZ
14473 Potsdam
Tel.: +49 (0)33843/624-18


Media contact:

Josef Zens  

Head of Public and Media Relations
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
14473 Potsdam
Phone: +49 331 288-1040

Additional News

Glacier ice algae boost Greenland's ice melt - nourished by phosphorus

Diamonds need Voltage

Faster earthquake early warning with artificial intelligence

Fragen und Antworten zum Erdbeben in Kroatien

Melody of an Alpine summit falling apart

Geothermal exploration with fibre optic seismics in Potsdam

Early warning system for dams at risk

Better calculation of stress in the underground

How hot can it be for life to exist deep below the ocean floor?

Earthquake Scenario for Large German City