2026-04-04T04:43:17Zhttp://doidb.wdc-terra.org/oaip/oai
oai:doidb.wdc-terra.org:70522021-03-15T08:42:35ZDOIDBDOIDB.GFZ
false4DOIDB.GFZ 10.5880/Kp.0001 Matzka, Jürgen Jürgen Matzka 0000-0001-9926-2796 GFZ German Research Centre for Geosciences, Potsdam, Germany Bronkalla, Oliver Oliver Bronkalla GFZ German Research Centre for Geosciences, Potsdam, Germany Tornow, Katrin Katrin Tornow GFZ German Research Centre for Geosciences, Potsdam, Germany Elger, Kirsten Kirsten Elger 0000-0001-5140-8602 GFZ German Research Centre for Geosciences, Potsdam, Germany Stolle, Claudia Claudia Stolle 0000-0002-5717-1623 GFZ German Research Centre for Geosciences, Potsdam, Germany Geomagnetic Kp index GFZ Data Services 2021 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 EARTH SCIENCE > SOLID EARTH > GEOMAGNETISM > GEOMAGNETIC INDICES > KP INDEX EARTH SCIENCE > SUN-EARTH INTERACTIONS > IONOSPHERE/MAGNETOSPHERE DYNAMICS > GEOMAGNETIC INDICES EARTH SCIENCE > SUN-EARTH INTERACTIONS > IONOSPHERE/MAGNETOSPHERE DYNAMICS > MAGNETIC FIELDS/MAGNETIC CURRENTS Matzka, Jürgen Jürgen Matzka 0000-0001-9926-2796 GFZ German Research Centre for Geosciences, Potsdam, Germany Matzka, Jürgen Jürgen Matzka 0000-0001-9926-2796 GFZ German Research Centre for Geosciences, Potsdam, Germany Bronkalla, Oliver Oliver Bronkalla GFZ German Research Centre for Geosciences, Potsdam, Germany Bronkalla, Oliver Oliver Bronkalla GFZ German Research Centre for Geosciences, Potsdam, Germany Bronkalla, Oliver Oliver Bronkalla GFZ German Research Centre for Geosciences, Potsdam, Germany Tornow, Katrin Katrin Tornow GFZ German Research Centre for Geosciences, Potsdam, Germany Tornow, Katrin Katrin Tornow GFZ German Research Centre for Geosciences, Potsdam, Germany Stolle, Claudia Claudia Stolle 0000-0002-5717-1623 GFZ German Research Centre for Geosciences, Potsdam, Germany Stolle, Claudia Claudia Stolle 0000-0002-5717-1623 GFZ German Research Centre for Geosciences, Potsdam, Germany Baillie, Orsi Orsi Baillie British Geological Survey (UK) Blais, Charles Charles Blais Natural Resources Canada (Canada) Calp, David David Calp Natural Resources Canada (Canada) Clarke, Ellen Ellen Clarke British Geological Survey (UK) Claycomb, Abram Abram Claycomb U.S. Geological Survey (US) Haseloff, Jürgen Jürgen Haseloff GFZ German Research Centre for Geosciences (Germany) Lewis, Andrew Andrew Lewis Geoscience Australia Linthe, Achim Achim Linthe GFZ German Research Centre for Geosciences, Potsdam, Germany Morris, Jake Jake Morris U.S. Geological Survey (US) Morschhauser, Achim Achim Morschhauser GFZ German Research Centre for Geosciences, Potsdam, Germany Petersen, Tanja Tanja Petersen The Institute of Geological & Nuclear Sciences Ltd (New Zealand) Reay, Sarah Sarah Reay British Geological Survey (UK) Schwarz, Gerhard Gerhard Schwarz Geological Survey of Sweden (Sweden) Willer, Anna Naemi Anna Naemi Willer Technical University of Denmark (Denmark) Worthington, Bill Bill Worthington U.S. Geological Survey (US) Geomagnetic Observatory Canberra (CNB) maintained by: Geoscience Australia (Australia) Geoscience Australia, Canberra, Australia Geomagnetic Observatory Brorfelde (BFE) maintained by: Technical University of Denmark (Denmark) Technical University of Denmark, Lyngby, Denmark Geomagnetic Observatory Eskdalemuir (ESK) maintained by: British Geological Survey (UK) British Geological Survey, Edinburg, UK Geomagnetic Observatory Eyrewell (EYR) maintained by: GNS Science (New Zealand) The Institute of Geological & Nuclear Sciences Ltd, Lower Hutt, New Zealand Geomagnetic Observatory Fredericksburg (FRD) maintained by: U.S. Geological Survey (US) U.S. Geological Survey, US Geomagnetic Observatory Hartland (HAD) maintained by: British Geological Survey (UK) British Geological Survey, UK Geomagnetic Observatory Lerwick (LER) maintained by: British Geological Survey (UK) British Geological Survey, UK Geomagnetic Observatory Meanook (MEA) maintained by: Natural Resources Canada (Canada) Natural Resources Canada, Canada Geomagnetic Observatory Niemegk (NGK) maintained by: GFZ German Research Centre for Geosciences (Germany) GFZ German Research Centre for Geosciences, Potsdam, Germany Geomagnetic Observatory Ottawa (OTT) maintained by: Natural Resources Canada (Canada) Natural Resources Canada, Canada Geomagnetic Observatory Sitka (SIT) maintained by: U.S. Geological Survey (US) U.S. Geological Survey, US Geomagnetic Observatory Uppsala (UPS) maintained by: Geological Survey of Sweden (Sweden) Geological Survey of Sweden, Sweden Geomagnetic Observatory Wingst (WNG) maintained by: GFZ German Research Centre for Geosciences (Germany) GFZ German Research Centre for Geosciences, Potsdam, Germany 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 1932-01-01 Dataset 10.1029/2020SW002641 http://isgi.unistra.fr/IAGABulletins/IATME_Bulletin_12b_Herbert_Weisman_Bartels_1949.pdf 10.1016/B978-1-4832-1304-0.50007-5 1.0 CC BY 4.0 Matzka et al. (2021) describe the state of the Kp index 70 years after its introduction and serve as a reference for users of the IAGA-endorsed Kp index as well as for the derived indices ap, Ap, Cp and C9 in their definitive and nowcast version as well as for 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. Please cite this data publication as well as the accompanying publication (Matzka et al., 2021) when using the Kp index or any of the derived indices obtained from this dataset or from its copies provided by GFZ or other institutions.

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.
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).
BFE (Brorfelde) maintained by: Technical Universtiy of Denmark (DTU) CNB (Canberra) maintained by: Geoscience Australia ESK (Eskdalemuir) maintained by: British Geological Survey EYR (Eyrewell) maintained by: GNS Sciences Limited FRD (Fredericksburg) maintained by: U.S. Geological Survey HAD (Hartland) maintained by: British Geological Survey LER (Lerwick) maintained by: British Geological Survey MEA (Meanook) maintained by: Natural Resources of Canada / Geological Survey of Canada NGK (Niemegk) maintained by: GFZ German Research Centre for Geosciences OTT (Ottawa) maintained by: Natural Resources of Canada / Geological Survey of Canada SIT (Sitka) maintained by: U.S. Geological Survey UPS (Uppsala) maintained by: Geological Survey of Sweden WNG (Wingst) maintained by: Federal Maritime and Hydrographic Agency Hamburg, GFZ German Research Centre for Geosciences Global coverage of the kp index -180 180 -90 90 Helmholtz-Gemeinschaft http://doi.org/10.13039/501100001656