In the time interval 1749-1818 a great part of missing daily relative sunspot numbers was reconstructed by nonlinear two-step method of interpolation. In the first step directly interpolated were gaps not longer than five days. In the second step the data were sorted in the so called Bartels scheme, i.e. in rows of a length of 27 days
subsequently ranged in a matrix. In thís step the missing data of longer gaps were interpolated columnwise, i.e. missing value at any position was interpolated from the data at same column positions of preceeding and folloving rows. The interpolation was limited to sequences of no more than four missing data. The procedure enables interpolate long gaps and simultaneously respect the 27-day variation of solar activity. A part of missing data in the intervals, where the frequency of observations was very low and has not fullfilled the limitations of the interpolation method. was
not interpolated. Annual tables of daily data are given in Appendix A, monthly and annual means in Appendix B, and annual plots of daily data in Appendix C. The differences between monthly and annual means of the primary observations and of the data completed by interpolation fluctuate around zero. The amplitude of fluctuations
depends inversely on the frequency of observations. Most conspicuous are the deviations in the time interval 1776-1795, when the frequency of observations was wery low or almost zero. The dispersion of monthly differences σ is ±13.7 R and
of annual differences ±9.3 R. The results give insight on the reliability of relative sunspot numbers in the investigated time interval. and Součástí článku jsou 2 apendixy:
- Appendix A Daily relative sunspot numbers 1749-1818
(s. 7-42)
- Appendix B Monthly and annual means of relative sunspot numbers 1749-1818 (s. 43-66)
The missing daily relative sunspot numbers in the time interval 1818-1848 were reconstructed by the nonlinear two-step method of interpolation. In the first step directly interpolated gaps were not longer than five days. In the second step, the data were sorted in the so called Bartels scheme, i.e. in rows of the length of 27 days
subsequently ranged in a matrix. The missing data of longer gaps were interpolated columnwise, i.e. the missing value at any position was interpolated from the data at the same positions of preceeding and following rows. The procedure enables to interpolate long gaps and simultaneously respect the 27-day data variation. The Appendix A contains annual tables of daily data, Appendix B gives monthly and annual means and Appendix C presents simutaneously annual plots of primary data and of those reconstructed by interpolation. The differences between the monthly and annual means of primary data and of data completed by interpolation are small and fluctuate around zero. Only in the time interval 1835-1842, when the frequency of observations was lowered, the amplitude of fluctuations is enhanced. The dispersion of monthly differences σ is ±4.3 R and of annual means ±1,1 R. The two-step method of interpolation was tested on the daily data series in the time interval 1918-1948. The sequence of missing daily data in the years 1818-1848 represents a masking function. The differences between the monthly and annual means of primary and modified data are small with fluctuations around zero and with dispersion σ for monthly differences ±2.7 R and for annual differences ±0.6 R. The small dispersion gives evidence about a high reliability of relative sunspot numbers derived from observations in the years
1818-1848 and also about the effectivity of the two-step method of interpolation. and Materiál obsahuje 3 (nestránkované) apendixy:
- Appendix A Daily relative sunspot numbers 1818-1848 [s. 6-22]
- Appendix B Monthly and annual means of relative sunsppot numbers 1818-1848 [s. 23-24]
- Appendix C Plots of daily relative sunspot numbers 1818-1848
[s. 25-56]
Based on the dependence of the maximum relative RM-number of the add 11-year cycle on the RM of the previous even cycle it is forecast that RM should exceed 200 in the next 11-year sunspot cycle No. 23. and Published in Bull. Astron. Inst. Czechosl. 42 (1991), 157-158
High resolution white light and Hα observations carried out at the Observatorio del Teide (Tenerife) witli the 40 cm Vacuum Telescope of the Kiepenheuer Institute (FRG), allow us to study the processes taking place during the development of 15 large active regions (flux larger than 5x1021Mx). The behaviour of the magnetic fragments which coalesce to form the mature spots, inform us about the nature of the subphotospheric flux rope. The following are the main findings;
(i) Fragments with typically 1021Mx preserve their identity and even survive to the decay of the sunspots.
(ii) Each fragment has a very precise location in the whole ensemble.
(iii) The incomplete coalescense of the fragments leaves interstices which are penetrated by hot gas. Tfiis gives a natural explanation of the umbral fine structures (ie. umbral dots and light bridges).
We have used force-free extrapolations of photospheric magnetic field observations from Marshall Space Fllght Center to compute the total intensity and circular polarisation of sunspot associated emission from active region 2502 in the period June 13 to 15, 1980. The computed maps were compared to high resolution observations of tne same active region obtained witn tne Westerbork Synthesis Radio Telescope, Tne most interesting aspect of tne active region was tne developement of a new spot between the proceeding and the following spots on June 14, wnich subsequently merged witn the preceeding spot. The new spot
was associated witn enhanced microwave emission with a peak brigtness temperature in excess of 4 10^6 K. Our model computations are In satisfactory agreement witn tne sunspot observations for June 13, nowever tbey falled to reproduce tne
enhanced emission associated witn tne new spot on June 14 and 15. We snow tnat unrealistic values of tne conductive flux are required for the interpretation of tne emission of the new sunspot in terms of thermal processes. We suggest tnat tnis source Is due to gyrosynchrotron radiation from mildly relativistic electrons accelerated by reslstive instabiltles in tne evolvlng magnetic field.
Problems, methods and results are discussed to model finestructures of sunspots, plages and prominences from observed data. The very small scales of those structures prevents so far their full resolution in a spectrum. Thus, twocomponent models of other indirect methods are used to deduce model atmosphere, magnetic and velocity field within these finestructures.
We review the basic features of oscillations observed at different height levels in the sunspot atmosphere, moreover, various possibilities for a theoretical interpretation are discussed. In the umbra oscillation power is concentrated in severa] period bands
(3 min., 5 min., and ≥ 20 min.) which on their part are composed of closely packed peaks. The observed amplitudes and phases of velocity and of intensity oscillations depend in a characteristic way on the period and on the height. These features are used to look for the most probable physical mechanisms which could produce the different modes: At subphotospheric depths two independent resonators are acting. A resonator for slow, quasi-transveree waves can explain the lifetimes of umbral dots (≥ 20 min.), while a resonator for fast (acoustic), quasi-longitudinal waves could result in the umbral 5-min. oscillations. The acoustic resonator strongly couples with the slow-mode longitudinal resonator at photospheric and chromospheric heights, the latter produces the resonance peaks in the 3-min. band. Running penumbral waves can be explained by the transformation of 5-min, waves from the convective zone in the almost horizontal magnetic field. The interpretation of oscillations provides a new method of probing not only subphotospheric, but also atmospheric layers of sunspots (e.g., of determining temperature gradients), thus completing customary spectroscopic diagnostics.