NCEI (formerly NGDC)
EMMA logo

Geomagnetic Kn, Ks, Km Indices

A full description of the indices Kn, Ks, Km is given in a monography,"Indices Kn, Ks et Km, 1964-1967", edited in 1968 by the Centre National de la Recherche Scientifique, 15 quai Anatole, France, 75007 Paris, which contains these indices for 2964-1967 while the International Association of Geomagnetism and Aeronony (IAGA) Bulletin NO. 39 contains those for 1959-1963. Yearly computations of these data are published in the series of IAGA Bulletin No.32. All
of them are available in digital form at the appropriate World Data Center. Briefly, the three-hourly indices Kn and Ks for the Northern and Southern Hemispheres respectively are derived from the K indices of observatories approximately well distributed in latitude and in longitude. The indices are standardized according to the distances of the stations to the auroral zones. The stations are arranged in groups representing a longitude sector in one of the hemispheres (5 in
the Northern Hemisphere, 4 in the Southern). The observatories currently in use are: MGD-Magadan, EYR-Eyrewell, PET-Petropavlovsk, LAU-Lauder, MMB-Memambetsu, CAN-Canberra, POD-Podkammenaya Tunguska, SVE-Sverdlovsk, GNA-Gnangara, NGK-Niemegk, KGL-Kerguelen, CZT-Crozet, HAD-Hartland, HER-Hermanus, OTT-Ottawa, AIA-Argentine Island, FRD-Fredericksburg, NEW-Newport, VIC-Victoria, TUC-Tucson The mean standardized K of each sector is converted into an equivalent amplitude and the
weighted (in longitude) averages and these amplitudes are converted back into Kn and Ks. Km is derived in the same way from am, the average of an and as. Indices an, as and am are expressed in gammas (one gamma equals one nanoTesla) and correspond to the magnetic activity level (as it can be inferred from K indices 0 at an invariant magnetic latitude of 50 degrees. Indices Kn, Ks and Km are expressed in the same units as Kp. Values published in these reports are only
provisional because in some months all observatories used in each longitude sector have not sent K indices at the right time and because K indices of Antarctic Stations have be rescaled at the end of each wintering.
Cite this dataset when used as a source.
  • ID not available.
Distribution Formats
  • ASCII
Distributor Justin Mabie
Space and Terrestrial Weather Specialist
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
(303) 497-6135
Justin.Mabie@noaa.gov
Dataset Point of Contact Justin Mabie
Space and Terrestrial Weather Specialist
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
(303) 497-6135
Justin.Mabie@noaa.gov
Time Period: 1983-01-01 to Present
Spatial Bounding Box Coordinates:
N: 90.000000
S: -90.000000
E: 180.000000
W: -180.000000
Documentation links not available.
Date(s)
  • publication: 1998-05-13
Edition: First
Dataset Progress Status Under development
Data Update Frequency: Monthly
Purpose: Monitor Geomagnetic Activity
Use Limitations
  • While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Originator(s)
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Publisher(s)
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Theme keywords NASA/GCMD Earth Science Keywords
  • EARTH SCIENCE > SOLID EARTH > Geomagnetism > Geomagnetic Indices
Uncontrolled Keywords
  • Ks, Kn, Km Indices
  • Geomagnetic Field
  • Azimuthal Component
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Place keywords NASA/GCMD Location Keywords
  • Global
  • Magnetosphere
Use Constraints
  • Use Constraints: None
Access Constraints
  • Access Constraints: No Constraints
Fees
  • Depends on the Data Set
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Last Modified: 2015-09-18
For questions about the information on this page, please email: Justin.Mabie@noaa.gov