caa a22 4500 445345918 CHVBK 20180317142828.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s11207-011-9716-7 doi (NATIONALLICENCE)springer-10.1007/s11207-011-9716-7 Multilevel Analysis of Oscillation Motions in Active Regions of the Sun [Elektronische Daten] [V. Abramov-Maximov, G. Gelfreikh, N. Kobanov, K. Shibasaki, S. Chupin] The nature of the three-minute and five-minute oscillations observed in sunspots is considered to be an effect of propagation of magnetohydrodynamic (MHD) waves from the photosphere to the solar corona. However, the real modes of these waves and the nature of the filters that result in rather narrow frequency bands of these modes are still far from being generally accepted, in spite of a large amount of observational material obtained in a wide range of wave bands. The significance of this field of research is based on the hope that local seismology can be used to find the structure of the solar atmosphere in magnetic tubes of sunspots. We expect that substantial progress can be achieved by simultaneous observations of the sunspot oscillations in different layers of the solar atmosphere in order to gain information on propagating waves. In this study we used a new method that combines the results of an oscillation study made in optical and radio observations. The optical spectral measurements in photospheric and chromospheric lines of the line-of-sight velocity were carried out at the Sayan Solar Observatory. The radio maps of the Sun were obtained with the Nobeyama Radioheliograph at 1.76cm. Radio sources associated with the sunspots were analyzed to study the oscillation processes in the chromosphere - corona transition region in the layer with magnetic field B=2000G. Ahigh level of instability of the oscillations in the optical and radio data was found. We used a wavelet analysis for the spectra. The best similarities of the spectra of oscillations obtained by the two methods were detected in the three-minute oscillations inside the sunspot umbra for the dates when the active regions were situated near the center of the solar disk. Acomparison of the wavelet spectra for optical and radio observations showed a time delay of about 50seconds of the radio results with respect to the optical ones. This implies an MHD wave traveling upward inside the umbral magnetic tube of the sunspot. For the five-minute oscillations the similarity in spectral details could be found only for optical oscillations at the chromospheric level in the umbral region or very close to it. The time delays seem to be similar. Besides three-minute and five-minute ones, oscillations with longer periods (8 and 15 minutes) were detected in optical and radio records. Their nature still requires further observational and theoretical study for even a preliminary discussion. Springer Science+Business Media B.V., 2011 Oscillations, solar nationallicence Radio emission, active regions nationallicence Sunspots, velocity nationallicence Waves, magnetohydrodynamic nationallicence Abramov-Maximov V. Central Astronomical Observatory at Pulkovo, Russian Acad. Sci., 196140, St. Petersburg, Russia aut Gelfreikh G. Central Astronomical Observatory at Pulkovo, Russian Acad. Sci., 196140, St. Petersburg, Russia aut Kobanov N. Institute of Solar-Terrestrial Physics, P.O. Box 4026, 664033, Irkutsk, Russia aut Shibasaki K. Nobeyama Solar Radio Observatory, Minamisaku, Nagano, Japan aut Chupin S. Institute of Solar-Terrestrial Physics, P.O. Box 4026, 664033, Irkutsk, Russia aut Solar Physics Springer Netherlands 270/1(2011-05-01), 175-189 0038-0938 270:1<175 2011 270 11207 https://doi.org/10.1007/s11207-011-9716-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9716-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Abramov-Maximov V. Central Astronomical Observatory at Pulkovo, Russian Acad. Sci., 196140, St. Petersburg, Russia aut NATIONALLICENCE 700 1- Gelfreikh G. Central Astronomical Observatory at Pulkovo, Russian Acad. Sci., 196140, St. Petersburg, Russia aut NATIONALLICENCE 700 1- Kobanov N. Institute of Solar-Terrestrial Physics, P.O. Box 4026, 664033, Irkutsk, Russia aut NATIONALLICENCE 700 1- Shibasaki K. Nobeyama Solar Radio Observatory, Minamisaku, Nagano, Japan aut NATIONALLICENCE 700 1- Chupin S. Institute of Solar-Terrestrial Physics, P.O. Box 4026, 664033, Irkutsk, Russia aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 270/1(2011-05-01), 175-189 0038-0938 270:1<175 2011 270 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer