Dr. H.-J. Linthe, mailto:kp_index@gfz-potsdam.deBoth recent and past tables (since 1932) are supplied as an archive on the FTP servers

- Denmark: ftp://ftp.dmi.min.dk/pub/Data/WDCC1/indices/kp-ap/
- Germany: ftp://ftp.gfz-potsdam.de/pub/home/obs/kp-ap/
- WWW access: http://www.gfz-potsdam.de/~kp_index/kp-ap/

Your mileage may vary with a different FTP program or the WWW access alternative.

Background information on geomagnetic indices and the classification of days is supplied at the WWW startpage http://www.gfz-potsdam.de/~kp_index/

- the columns for the solar radio flux (columns 66-71) are not maintained or used by our programs
- the list of most quiet and most disturbed days is not contained in this format; if you need those, please refer to the other tables (kpyymm.tab)
- we do not guarantee the correctness of the international sunspot number R; these values are published separately (Brussels, Belgium)

`Ks` indices range in 28 steps from 0 (quiet) to 9 (greatly
disturbed) with fractional parts expressed in thirds of a unit.
A `Ks`-value equal to 27, for example, means 2 and 2/3 or 3-;
a `Ks`-value equal to 30 means 3 and 0/3 or 3 exactly;
and a `Ks`-value equal to 33 means 3 and 1/3 or 3+.
The arithmetic mean of the `Ks` values scaled at the
13 observatories listed above gives `Kp`.

Column Format Description ====== ====== =========== 1- 2 i2 yy, last two digits of year 3- 4 i2 mm, month (1-12) 5- 6 i2 dd, day of month (1-31) 7-10 i4 Bartels solar rotation number - a sequence of 27-day intervals counted continuously from February 8, 1832 11-12 i2 Number of day within the Bartels 27-day cycle 13-28 8i2 3-hourly Kp indices (0-3, 3-6, 6-9, 9-12, 12-15, 15-18, 18-21, 21-24 UT) 29-31 i3 Daily Kp sum, expressed to the nearest third of a unit (supplied only for tradition, use Ap scientific purposes!) 32-55 8i3 3-hourly ap indices (0-3, 3-6, 6-9, 9-12, 12-15, 15-18, 18-21, 21-24 UT) 56-58 i3 Ap equivalent daily amplitude - the arithmetic mean of the day's eight ap values 59-61 f3.1 Cp or Planetary Daily Character Figure - a qualitative estimate of overall level of magnetic activity for the day determined from the sum of the eight ap amplitudes. Cp ranges, in steps of one-tenth, from 0 (quiet) to 2.5 (highly disturbed) 62-62 i1 C9 - a conversion of the 0 to 2.5 range of the Cp index to one digit between 0 and 9 63-65 i3 International Sunspot Number. Records contain * Zurich number through December 31, 1980 * International Brussels number thereafter 66-70 f5.1 Ottawa 10.7 cm Solar Radio Flux adjusted to 1 AU - measured at 1700 UT daily and expressed in units of 10^-22 W/m^2/Hz. Observations began on February 14, 1947. From that date through December 31, 1973, the fluxes given here do not reflect the revisions Ottawa made in 1966. 71-71 i1 Flux Qualifier 0: indicates flux required no adjustment; 1: indicates flux required adjustment for burst in progress at time of measurement; 2: indicates a flux approximated by either interpolation or extrapolation; 3: indicates no observation.

For questions concerning specific data or the contents of this page, please contact:

Dr. H.-J. Linthe, mailto:kp_index@gfz-potsdam.de