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M. I. Pishkalo 《Kinematics and Physics of Celestial Bodies》2013,29(1):37-43
Correlations are investigated between the pattern of solar activity described by the smoothed monthly relative sunspot numbers (Wolf numbers) near the minimum of a solar cycle and the cycle amplitude. The closest correlation is found between the amplitude of a solar cycle and the sum of the decrease in activity over two years prior to the cycle minimum and the increase in activity over two years after the minimum; the correlation coefficient between these parameters is 0.92. This parameter is used as a precursor to predict the amplitude of solar cycle 24, which is expected to reach its maximum amplitude (85 ± 12) in February 2014. Based on the correlations between the mean parameters of solar cycles, cycle 24 is expected to last for approximately 11.3 years and the minimum of the next cycle 25 is predicted for May 2020. 相似文献
3.
Shape and structure of the solar corona during the August 1, 2008, total solar eclipse is reported. The August 1, 2008, corona
is classified as of near-minimum type with well developed northern and southern polar ray systems over polar coronal holes
and several streamers of different brightness at the middle and low heliographic latitude. The flattening index was found
to be 0.21. 相似文献
4.
Mykola I. Pishkalo 《Solar physics》2014,289(5):1815-1829
Correlations between monthly smoothed sunspot numbers at the solar-cycle maximum [R max] and duration of the ascending phase of the cycle [T rise], on the one hand, and sunspot-number parameters (values, differences and sums) near the cycle minimum, on the other hand, are studied. It is found that sunspot numbers two?–?three years around minimum correlate with R max or T rise better than those exactly at the minimum. The strongest correlation (Pearson’s r=0.93 with P<0.001 and Spearman’s rank correlation coefficient r S=0.95 with P=9×10?12) proved to be between R max and the sum of the increase of activity over 30 months after the cycle minimum and the drop of activity over 30 or 36 months before the minimum. Several predictions of maximal amplitude and duration of the ascending phase for Solar Cycle 24 are given using sunspot-number parameters as precursors. All of the predictions indicate that Solar Cycle 24 is expected to reach a maximal smoothed monthly sunspot number (SSN) of 70?–?100. The prediction based on the best correlation yields the maximal amplitude of 90±12. The maximum of Solar Cycle 24 is expected to be in December 2013?–?January 2014. The rising and declining phases of Solar Cycle 24 are estimated to be about 5.0 and 6.3 years, respectively. The minimum epoch between Solar Cycles 24 and 25 is predicted to be at 2020.3 with minimal SSN of 5.1?–?5.4. We predict also that Solar Cycle 25 will be slightly stronger than Solar Cycle 24; its maximal SSN will be of 105?–?110. 相似文献
5.
N. I. Pishkalo 《Kinematics and Physics of Celestial Bodies》2012,28(4):183-188
Values of the Nikol??skii geometric flattening index of the solar corona, H, have been collected for 77 total solar eclipses from 1860 to 2010. The dependence of the H index on the Wolf number and the phase of solar activity is studied. The H index is found to take values in the range 0.9 to 2.5 and to anticorrelate with solar activity: the maximum values of the index are observed at solar minima and the minimum values are observed at solar maxima. In addition, the correlations between the H index and the Ludendorff photometric flattening index a + b and between the H index and extent of polar ray systems along the limb are investigated. 相似文献
6.
The structure and the shape of the solar corona during the total solar eclipse on March 29, 2006 were studied. The corona was of the intermediate pre-minimal type, it had northern and southern polar ray systems above the polar coronal holes and six streamers of different brightness in the middle and low heliographic latitudes. All the coronal structural features were found to have counterparts at the photosphere-chromosphere level on the limb and near it. The corona’s photometric flattening index was equal to 0.17. 相似文献
7.
M. I. Pishkalo 《Astronomische Nachrichten》1994,315(5):391-397
Hα profiles of chromospheric spicules computed for a variety of rotational behavior are compared with an observed profile, which was derived by averaging 11 Hα profiles taken near times of maximum spicule intensity. If turbulent velocity is small or equals zero, calculated profiles are in good agreement with the observed one under the conditions that rotation is non-rigid (faster rotation further away from the axis of the spicule) and the source function decreases in the direction from the spicule axis to the periphery. The comparison of calculated and observed tilts of spicule spectra relative to the direction of dispersion seems to corraborate the non-rigid character of spicular rotation. 相似文献
8.
Data on the value and sign of the circumpolar magnetic field of the Sun at a maximum of its activity in cycle 24 have been analyzed. The data were obtained from observations at the Wilcox Solar Observatory and from synoptic maps of the magnetic field built in the SOLIS project (SOLIS stands for Synoptic Optical Long-term Investigations of the Sun) and with the Helioseismic and Magnetic Imager (HMI). We studied the dynamics of the total magnetic fields in the circumpolar latitudinal zones of different extension in the northern and southern hemispheres. The epochs of the sign reversal of the polar magnetic field were determined. It was found that, in cycle 24, the magnetic field polarity changed three times in the northern hemisphere and only once in the southern one. In the northern hemisphere, the reversal of the polar magnetic field finished approximately a year earlier than that in the southern one. The obtained results are compared to the data on the sign reversal of the polar magnetic field of the Sun reported for the previous solar cycles. 相似文献
9.
Mykola I. Pishkalo 《Solar physics》2006,233(2):277-290
We have investigated the correlation between the relative sunspot number and tilt of the heliospheric current sheet (HCS)
in solar cycles 21–23. Strong and highly significant positive correlation (r > 0.8, P < 0.001) was found for corresponding data in the time interval from May 1976 through December 2004. Cross-correlation analysis
does not reveal any time shift between the data sets. Reconstructed values of the HCS tilt, for the time interval before 1976,
are found using sunspot numbers. To take different amplitude of solar cycles into account they were then normalized to zero
in the minima of the solar activity and to average in solar cycles 21–23 maximal calculated HCS tilt in the maxima. These
normalized reconstructed HCS data are compared with the angular positions of the brightest coronal streamers observed during
total solar eclipses in 1870–2002, and their agreement is better for the minima of the solar activity than for the maxima. 相似文献
10.
M. I. Pishkalo 《Kinematics and Physics of Celestial Bodies》2008,24(5):242-247
The correlation between various parameters of solar cycles 1–23 is investigated. The derived regressions are used to make predictions of solar cycles 24 and 25. It is expected that solar cycle 24 will reach its maximum amplitude of 110.2 ± 33.4 in April–June 2012 and the next minimum will occur in December 2018–January 2019. The duration of solar cycle 24 will be about 11.1 years. Solar cycle 25 will reach its maximum amplitude of 112.3 ± 33.4 approximately in April–June 2023. 相似文献