Indices of Global Geomagnetic Activity -------------------------------------- Geomagnetic Kp Index and ap, Ap, Cp and C9 Indices The planetary three-hour-range index Kp 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 indices and the classification of international Q-days and D-days are derived from the Kp index. DOI of the dataset: https://doi.org/10.5880/Kp.0001 Dataset described in: Matzka, J., Stolle, C., Yamazaki, Y., Bronkalla, O. and Morschhauser, A., 2021. The geomagnetic Kp index and derived indices of geomagnetic activity. Space Weather, https://doi.org/10.1029/2020SW002641 Data publication: Matzka, J., Bronkalla, O., Tornow, K., Elger, K. and Stolle, C., 2021. Geomagnetic Kp index. V. 1.0. GFZ Data Services, https://doi.org/10.5880/Kp.0001 Licence of the dataset and plots: CC BY 4.0 References * Bartels, J., 1949. The standardized index, Ks, and the planetary index, Kp. IATME Bulletin, 12b, 97-120 * Bartels, J., 1957. The technique of scaling indices K and Q of geomagnetic activity, Ann. Intern. Geophys. Year 4, 215-226 * Bartels, J., 1957. The geomagnetic measures for the time-variations of solar corpuscular radiation, described for use in correlation studies in other geophysical fields, Ann. Intern. Geophys. Year 4, 227-236 * Matzka, J., Stolle, C., Yamazaki, Y., Bronkalla, O. and Morschhauser, A., 2021. The geomagnetic Kp index and derived indices of geomagnetic activity. Space Weather, https://doi.org/10.1029/2020SW002641 Matzka, J., Bronkalla, O., Tornow, K., Elger, K. and Stolle, C., 2021. Geomagnetic Kp index. V. 1.0. GFZ Data Services, https://doi.org/10.5880/Kp.0001 * Mayaud, P.N., 1980. Derivation, Meaning and Use of Geomagnetic Indices, Geophysical Monograph 22, Am. Geophys. Union, Washington D.C. * Menvielle, M. and Berthelier, A., 1991. The K-derived planetary indices: description and availability, Rev. Geophys. 29, 3, 415-432 for a complete review of the present IAGA indices; * Rangarajan, G.K., 1989. Indices of magnetic activity, in: Geomagnetism (Ed. I.A. Jacobs), Academic, San Diego * Siebert, M., 1971. Masszahlen der erdmagnetischen Aktivitaet, in: Handbuch der Physik, vol. 49/3, 206-275, Springer, Berlin, Heidelberg * Siebert, M. and Meyer, J. 1996. Geomagnetic Activity Indices, in: The Upper Atmosphere (Eds. W. Dieminger et al.), 887-911, Springer Berlin Heidelberg, 1996; Sources of Kp and derived indices * Since January 1997: GFZ German Research Centre for Geosciences Adolf-Schmidt-Observatory for Geomagnetism Lindenstrasse 7 D-14823 Niemegk Germany o E-mail distribution (contact Juergen Matzka, mailto:kp_index@gfz-potsdam.de) o https://doi.org/10.5880/Kp.0001 (monthly update) o ftp://ftp.gfz-potsdam.de/pub/home/obs/kp-ap/ (two-weekly update) o ftp://ftp.gfz-potsdam.de/home/obs/Kp_ap_Ap_SN_F107 (near real-time) * Until January 1997: Institut fuer Geophysik Universitaet Goettingen Germany * World Data Center for Geomagnetism, Copenhagen DTU Space, Technical University of Denmark o FTP server: ftp://ftp.space.dtu.dk/WDC/indices/kp-ap/ (two-weekly update) * World Data Centre for Geomagnetism, Kyoto Japan http://wdc.kugi.kyoto-u.ac.jp/kp/index.html Structure of the FTP sites The kp-ap/ directory contains readme.txt (text file) This readme file. music.exe (binary executable file) A PC executable program for 386 or higher machines. music.exe reads Kp/ap values in WDC format and produces a PostScript file with Bartels Kp music diagram. Download music.exe using binary mode. The data file ssc.dat is also required to run music.exe. ssc.dat (text data file) List of sudden commencements (ssc), partly preliminary. ap_monyr.ave (text file) A table with monthly and yearly averages of Ap. tab/ (subdirectory) Contains the monthly Kp/ap tables since January 1994 in a simple text format readable for both humans and computers (*.tab). The file tab_fmt.txt provides a format description. wdc/ (subdirectory) Contains the monthly Kp/ap tables and much more information since January 2000 in condensed tables (ASCII format), the WDC format. The file wdc_fmt.txt provides a format description. This format does not contain any information on the quiet and most disturbed days as the tables in the tab directory do. wdc/yearly/ (subdirectory) Contains the yearly files since 1932 in the WDC format. music/ (subdirectory) Contains the Kp values in the Bartels musical diagram (PostScript format and PDF format), which is very helpful in visualizing the indices, for the last 4 to 5 solar rotation, for each month since January 2000. music/yearly (subdirectory) Contains the Kp values in the Bartels musical diagram (PostScript format and PDF format) for each year since 1932. sn9c9/ (subdirectory) Contains the three-day mean sunspot number and Kp values as contracted values SN9 and C9 in graphical form (PS and PDF format) quietdst/ (subdirectory) Contains tables of the quietest and most disturbed days for all months since Jan 1932. (Values since 1900 also supplied, use with caution.) kp-freq/ (subdirectory) Contains tables of frequencies of Kp indices. ---------------------------------------------------------------------------- URL: https://www.gfz-potsdam.de/kp-index/ Last modified: March 15, 2021 by Juergen Matzka