caa a22 4500 445347279 CHVBK 20180317142832.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s11207-011-9822-6 doi (NATIONALLICENCE)springer-10.1007/s11207-011-9822-6 Quasi-periodic Oscillations of Solar Active Regions in Connection with Their Flare Activity - NoRH Observations [Elektronische Daten] [V. Abramov-Maximov, G. Gelfreikh, K. Shibasaki] The sunspot-associated sources at the frequency of 17GHz give information on plasma parameters in the regions of magnetic field about B=2000G at the level of the chromosphere-corona transition region. The observations of short period (from one to ten minutes) oscillations in sunspots reflect propagation of magnetohydrodynamic (MHD) waves in the magnetic flux tubes of the sunspots. We investigate the oscillation parameters in active regions in connection with their flare activity. We confirm the existence of a link between the oscillation spectrum and flare activity. We find differences in the oscillations between pre-flare and post-flare phases. In particular, we demonstrate a case of powerful three-minute oscillations that start just before the burst. This event is similar to the cases of the precursors investigated by Sych etal. (Astron. Astrophys. 505, 791, 2009). We also found well-defined eight-minute oscillations of microwave emission from sunspot. We interpret our observations in terms of a relationship between MHD waves propagating from sunspots and flare processes. Springer Science+Business Media B.V., 2011 Oscillations, solar nationallicence Radio emission, active regions nationallicence Corona, radio emission nationallicence Radio bursts, association with flares 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 Shibasaki K. Nobeyama Solar Radio Observatory, Minamisaku, Nagano, Japan aut Solar Physics Springer Netherlands 273/2(2011-11-01), 403-412 0038-0938 273:2<403 2011 273 11207 https://doi.org/10.1007/s11207-011-9822-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9822-6 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- Shibasaki K. Nobeyama Solar Radio Observatory, Minamisaku, Nagano, Japan aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 273/2(2011-11-01), 403-412 0038-0938 273:2<403 2011 273 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer