Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

N.A. Barkhatov at al. from July, 18th till July, 22nd, 2004 is shown. In addition for comparison on this plot Kp calculated by us on the basis of original magnetograms, and also the published official values of Kp are resulted. Some discrepancy of last two indices use in our case public magnetograms is caused. While published official Kp on a basis magnetograms «for internal using» is calculated. Kp official Kp recalc ] Kp clear 15 20 25 30 35 3 hours/div Fig. 4. Fragment of sequence of values from July, 18th to July, 22nd 2004 of the recalculated (clear) index of Kp on the basis o f cleared magnetograms (light columns), published values of the Kp-index (black columns) and calculated by us without clearing magnetograms (grey columns). 5. Conclusions The mid-annual disorder of values between published official (Kp official) and the corrected index (Kp clear) ±0.9 point in a digital index scale is observed. Between calculated by us on the basis o f without clearing magnetograms (Kp recalc) and the corrected index (Kp clear) the disorder ±0.7 point has made. It has appeared that in 80% of cases of value o f published official Kp the calculated index on the basis of cleared magnetograms is exceeded. By results of the executed comparative analysis we will assume that the error of an official planetary Kp-index shown during the periods strong magnetospheric disturbances to true values on the average 25% not less than in 60% of cases is added. Thus, the use proposed correct Kp-index to avoid excessive influence of the polar sources and the planetary geomagnetic disturbance more reliably to estimate. A cknow ledgm en ts. Work is executed at partial support under grant of the RFBR 09-05-00495, and also program Ministry o f Education and Science «Development of higher school scientific potential (2009-2010, project N 1623)». References Bartels J., N. H. Heck, and H. F. Johnston, The three-hour-range index measuring geomagnetic activity, Terr. Magn. Atmos. Electr., 44,411-454, 1939. Bartels J., The standardized index, Ks, and the planetary index, Kp, IATME Bull. 12b, p. 97, Int. Union of Geod. and Geophys., Paris, 1949. Kazue Takahashi, Bruce A. Toth, John V. Olson, An automated procedure for near-real-time Kp estimates // Journal of geophysical research, V. 106, No A10, p. 21017-21032, 2001. Kozyreva O.V., Kleimenova N.G., Estimation of Storm Time Level of Day Side Wave Geomagnetic Activity Using a New ULF Index // Geomagnetism and Aeronomy, V. 48, № 4, p. 491-499, 2008. Mayaud P.N., Atlas of К -indices, Part 1, in 1AGA Bull. 21, Int. Union of Geod. and Geophys., Paris, 1967. 16