Differential rotation of solar structural formations from observations in the He I λ 1083 nm line
|1Zyelyk, Ya.I, 2Stepanian, NN, 3Andreyeva, OA |
1Space Research Institute of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Kyiv, Ukraine
2Scientific-Research Institute “Crimean Astrophysical Observatory” of the Ministry for Education and Science of Ukraine, Nauchny, AR Crimea, Ukraine
3Scientific-Research Institute “Crimean Astrophysical Observatory” of the Ministry for Education and Science of Ukraine, Nauchny, Crimea, Ukraine
|Kosm. nauka tehnol. 2009, 15 ;(1):44-56|
|Publication Language: Russian|
Using spectral analysis methods, we estimated some characteristics of the differential rotation for three types of the solar structures observed in the upper chromosphere, in 10-degree latitude zones in the characteristic period intervals during last three cycles of the solar activity, namely, 1) significant stationary periodic rotation components during three cycles; 2) temporal variationsof periodic rotation components at different latitudes within the bounds of each cycle on the basis of the results of the spectral analysis in the sliding temporal one-year window with the half-year shift for the overall 26-year observation interval. It is found that for all the latitudinal distributions of all structure types the total power of processes in each of several intervals of significant rotation periods varies with time both during each cycle and from cycle to cycle. The total power of the processes for the active regions with spots and floccules differs essentially at high latitudes and is close to good agreement at low ones. The total power variations with latitude for coronal holes differ essentially from its variations for active regions and floccules. The differential rotation measure for all the solar structures under consideration varies with time, even the moments of change of its sign are observed. We analyzed briefly the evolution factors of differential rotation of solar formations under consideration with latitude and time, expressing in various nature, sizes, lifetime of these structures, depth of their sources occurrence and character of proper motions.
|Keywords: differential rotation, spectral analysis, Sun|
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28. Welch P. D. The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms. IEEE Trans. Audio Electroacoustics, Vol. AU–15, 70–73 (June 1967).