Author:

Keywords:

Science & Technology, Physical Sciences, Astronomy & Astrophysics, SOLAR RADIO-BURSTS, POLARIZATION, FREQUENCY, FEATURES, RANGE, 0201 Astronomical and Space Sciences, 5101 Astronomical sciences, 5109 Space sciences

Abstract:

© 2015, Springer Science+Business Media Dordrecht. An event on 14 June 2012, observed with the radio telescopes UTR-2 (Kharkov, Ukraine), URAN-2 (Poltava, Ukraine), and NDA (Nançay, France) during a joint Summer campaign, is analyzed and discussed. The high solar activity resulted in a storm of spikes, and a storm of Type III bursts, Type IIIb bursts, and a Type IV burst observed in the decameter band. During the observed time interval, the average flux of radio emission changed twice. Using spikes as a tool for diagnostics of plasma parameters, we followed variations of the coronal temperature and the coronal magnetic field in the observed time interval. Thus, in frames of the model described in this article the observed decameter spikes’ durations of 0.3 – 1 seconds correspond to the coronal plasma temperatures of ≈0.1–0.6×106K${\approx}\, 0.1\,\mbox{--}\,0.6 \times10^{6}~\mbox{K}$. At the same time the spikes’ frequency bandwidths of 25 – 80 kHz give us the magnetic-field value of about 2 G.