Geomagnetic Kp index

Cite as:

Matzka, Jürgen; Bronkalla, Oliver; Tornow, Katrin; Elger, Kirsten; Stolle, Claudia (2021): Geomagnetic Kp index. V. 1.0. GFZ Data Services. https://doi.org/10.5880/Kp.0001

Status

I N R E V I E W : Matzka, Jürgen; Bronkalla, Oliver; Tornow, Katrin; Elger, Kirsten; Stolle, Claudia (2021): Geomagnetic Kp index. V. 1.0. GFZ Data Services. https://doi.org/10.5880/Kp.0001

Abstract

This data publication includes the IAGA-endorsed Kp index of geomagnetic activity as well as the derived indices ap, Ap, Cp and C9 in their definitive and nowcast version and the International Quiet and Disturbed Days. This dataset is provided by GFZ and derived from indices or near real-time geomagnetic observatory data provided by 13 contributing observatories. The Kp index and the derived products are distributed by GFZ and they are redistributed by various data centers and databases. When using the Kp index or any of the derived products of this dataset, please cite this data publication as well as the accompanying publication Matzka et al. (2021), which serves as a contemporary reference for users and describes the dataset and the state of the Kp index 70 years after its introduction.

The Kp index
The Kp index was introduced by Bartels (1949). We follow here generally the notation of Bartels (1957). A comprehensive list of references on the Kp index is provided in Matzka et al. (2021), which also describes the near real-time distribution of the indices.

DOI and versioning
With the introduction of the DOI ‘https://doi.org/10.5880/Kp.0001’ for the dataset, the DOI landing page and the associated FTP server linked to this DOI become the dataset's primary archive (while the other established index distribution mechanisms at GFZ will be maintained in parallel). With the DOI, the dataset can grow with time, but a change of the data, once published, is not possible. If necessity arises in the future to correct already published values, then the corrected dataset will be published with a new DOI. Older DOIs and data sets will then still be available. For each DOI, an additional versioning mechanism will be available to document changes to the files such as format changes, which do not affect the integrity of the data. The DOI 10.5880/Kp.0001 identifies the current version.

Additional Information

The dataset is organised in yearly files, which, for the current year, are updated on a monthly basis. Typically, during the second week of a month, the data for the previous month is calculated and appended to the current year's file, both for the definitive and nowcast version. While the definitive Kp (and derived indices) are calculated from K values provided by the contributing observatories, the nowcast Kp (and derived indices) are calculated at GFZ from observatory data provided by the contributing observatories.

The data are distributed in ASCII files. All files start with 10 header lines, each starting with a number sign (#, hash) and containing DOI as well as license information. Note that leading zeroes are not shown, they are represented by blanks. Missing data would be represented by -1.

For more information, please refer to the associated data description and Matzka et al. (2021).

Authors

Matzka, Jürgen;GFZ German Research Centre for Geosciences, Potsdam, Germany
Bronkalla, Oliver;GFZ German Research Centre for Geosciences, Potsdam, Germany
Tornow, Katrin;GFZ German Research Centre for Geosciences, Potsdam, Germany
Elger, Kirsten;GFZ German Research Centre for Geosciences, Potsdam, Germany
Stolle, Claudia;GFZ German Research Centre for Geosciences, Potsdam, Germany

Contact

Matzka, Jürgen; GFZ German Research Centre for Geosciences, Potsdam, Germany;
Stolle, Claudia; GFZ German Research Centre for Geosciences, Potsdam, Germany;
Bronkalla, Oliver; GFZ German Research Centre for Geosciences, Potsdam, Germany;

Contributors

Baillie, Orsi; Blais, Charles; Calp, David; Clarke, Ellen; Claycomb, Abram; Haseloff, Jürgen; Lewis, Andrew; Linthe, Achim; Morris, Jake; Morschhauser, Achim; Petersen, Tanja; Reay, Sarah; Schwarz, Gerhard; Willer, Anna Naemi; Worthington, Bill; Geomagnetic Observatory Canberra (CNB) maintained by: Geoscience Australia (Australia); Geomagnetic Observatory Brorfelde (BFE) maintained by: Technical University of Denmark (Denmark); Geomagnetic Observatory Eskdalemuir (ESK) maintained by: British Geological Survey (UK); Geomagnetic Observatory Eyrewell (EYR) maintained by: GNS Science (New Zealand); Geomagnetic Observatory Fredericksburg (FRD) maintained by: U.S. Geological Survey (US); Geomagnetic Observatory Hartland (HAD) maintained by: British Geological Survey (UK); Geomagnetic Observatory Lerwick (LER) maintained by: British Geological Survey (UK); Geomagnetic Observatory Meanook (MEA) maintained by: Natural Resources Canada (Canada); Geomagnetic Observatory Niemegk (NGK) maintained by: GFZ German Research Centre for Geosciences (Germany); Geomagnetic Observatory Ottawa (OTT) maintained by: Natural Resources Canada (Canada); Geomagnetic Observatory Sitka (SIT) maintained by: U.S. Geological Survey (US); Geomagnetic Observatory Uppsala (UPS) maintained by: Geological Survey of Sweden (Sweden); Geomagnetic Observatory Wingst (WNG) maintained by: GFZ German Research Centre for Geosciences (Germany)

Keywords

Kp, Kp index, ap index, Ap index, Cp index, C9 index, International Quiet and Disturbed Days, definitive index, nowcast index, geomagnetism, space weather, space physics