Working Group on Geomagnetic Data and Indices
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Report on Kp, ap, Ap, Cp, C9, Q-days and D-days

IAGA 1997, Uppsala, Working Group V-2,
Wed Aug 6, 1997

presented by Kevin Ivory (representing Prof. M. Siebert)

This is the final report on that part of the International Service of Geomagnetic Indices (ISGI) carried out at the Geophysics Institute at Göttingen, hereafter referred to as Kp-Center Göttingen. It originated in the work of the late Prof. Bartels who introduced the geomagnetic indices Kp, ap, Ap, Cp and C9 in the years around 1950. Since 1951, monthly tables with definitive data of the Bartels indices have been distributed within the scope of ISGI. Since 1957, with the beginning of the International Geophysical Year, the tables were edited half-monthly. The monthly tables were supplemented by musical diagrams of Kp, semi-graphic tables of C9 and lists of the quietest and most disturbed days (Q-days and D-days). Normally the data were available within less than four weeks after the end of each period concerned.

While over all the decades since 1951 the distribution of the data took place by mail, the recent development in the field of electronic data transmission was fully incorporated in this service. So, as an additional offer, the latest tables of indices are immediately distributed per email to a list of interested scientists worldwide after calculation on a half-monthly basis. Archives of these indices from 1932 through the most recently calculated values are offered for public access on several anonymous FTP servers as well as on a well-documented World Wide Web server.

Since the death of Prof. Bartels in 1964, Prof. Siebert has been responsible for the service of the Kp-Center Göttingen up to the end of 1996, that is already six years in excess of his retirement. Due to changes in the fields of activity of the Geophysics Institute at Göttingen, an arrangement has been made to terminate the Kp service at Göttingen and to continue this service at the Adolf-Schmidt-Observatorium Niemegk, which is an observatory of the GeoForschungsZentrum (GFZ) Potsdam. The transfer from Göttingen to Niemegk happened without any interruption of service; the Kp-Center Göttingen closed at the end of 1996, which is the reason for this final report from Göttingen.

Due to the fact that the series of the Bartels indices have been extended backwards until 1932, 65 annual sets of these data covering six solar cycles have been made available by this service for use of the scientific community. This, of course, was possible only due to the cooperation and help of so many persons all over the world, especially members of the Geophysics Institute of the University of Göttingen, the financial support by the Göttingen Academy of Sciences and last but not least the steady contributions of the Kp observatories over so many years. All of them cordial thanks.

For page content questions please contact: Kevin Ivory

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